diff --git a/en_US.ISO8859-1/books/handbook/printing/chapter.sgml b/en_US.ISO8859-1/books/handbook/printing/chapter.sgml index 596b90c8eb..faff1afa92 100644 --- a/en_US.ISO8859-1/books/handbook/printing/chapter.sgml +++ b/en_US.ISO8859-1/books/handbook/printing/chapter.sgml @@ -1,4672 +1,4644 @@ Printing - - Contributed by &a.kelly; 30 September - 1995 - - In order to use printers with FreeBSD, you will need to set them up to - work with the Berkeley line printer spooling system, also known as the LPD - spooling system. It is the standard printer control system in FreeBSD. - This section introduces the LPD spooling system, often simply called - LPD. - - If you are already familiar with LPD or another printer spooling - system, you may wish to skip to section Restructured and updated by &a.jim;, March + 2000. + + + Synopsis + + In order to use printers with FreeBSD, you will need to set them + up to work with the Berkeley line printer spooling system, also + known as the LPD spooling system. It is the standard printer + control system in FreeBSD. This chapter introduces the LPD spooling + system, often simply called LPD, and will guide you through it's + configuration. + + If you are already familiar with LPD or another printer spooling + system, you may wish to skip to section Setting up the spooling system. - + + - What the Spooler Does + Introduction - LPD controls everything about a host's printers. It is responsible - for a number of things: + LPD controls everything about a host's printers. It is + responsible for a number of things: - It controls access to attached printers and printers attached to - other hosts on the network. + It controls access to attached printers and printers + attached to other hosts on the network. - + It enables users to submit files to be printed; these submissions are known as jobs. - + - It prevents multiple users from accessing a printer at the same - time by maintaining a queue for each + It prevents multiple users from accessing a printer at the + same time by maintaining a queue for each printer. - + - It can print header pages (also known as - banner or burst pages) so - users can easily find jobs they have printed in a stack of - printouts. + It can print header pages (also known + as banner or burst + pages) so users can easily find jobs they have printed in a + stack of printouts. - + It takes care of communications parameters for printers connected on serial ports. - + It can send jobs over the network to another LPD spooler on another host. - + It can run special filters to format jobs to be printed for various printer languages or printer capabilities. - + It can account for printer usage. - - Through a configuration file, and by providing the special filter - programs, you can enable the LPD system to do all or some subset of the - above for a great variety of printer hardware. - - - - Why You Should Use the Spooler - - If you are the sole user of your system, you may be wondering why - you should bother with the spooler when you do not need access control, - header pages, or printer accounting. While it is possible to enable - direct access to a printer, you should use the spooler anyway - since - - - - LPD prints jobs in the background; you do not have to wait for - data to be copied to the printer. - - - - LPD can conveniently run a job to be printed through filters to - add date/time headers or convert a special file format (such as a - TeX DVI file) into a format the printer will understand. You will - not have to do these steps manually. - - - - Many free and commercial programs that provide a print feature - usually expect to talk to the spooler on your system. By setting up - the spooling system, you will more easily support other software you - may later add or already have. - - + + Through a configuration file + (/etc/printcap), and by providing the special + filter programs, you can enable the LPD system to do all or some + subset of the above for a great variety of printer hardware. + + + Why You Should Use the Spooler + + If you are the sole user of your system, you may be wondering + why you should bother with the spooler when you do not need access + control, header pages, or printer accounting. While it is + possible to enable direct access to a printer, you should use the + spooler anyway since: + + + + LPD prints jobs in the background; you do not have to wait + for data to be copied to the printer. + + + + LPD can conveniently run a job to be printed through + filters to add date/time headers or convert a special file + format (such as a TeX DVI file) into a format the printer will + understand. You will not have to do these steps + manually. + + + + Many free and commercial programs that provide a print + feature usually expect to talk to the spooler on your system. + By setting up the spooling system, you will more easily + support other software you may later add or already + have. + + + - + - Setting Up the Spooling System - - To use printers with the LPD spooling system, you will need to set - up both your printer hardware and the LPD software. This document - describes two levels of setup: - + Basic Setup + + To use printers with the LPD spooling system, you will need to + set up both your printer hardware and the LPD software. This + document describes two levels of setup: + See section Simple Printer - Setup to learn how to connect a printer, tell LPD how to + Setup to learn how to connect a printer, tell LPD how to communicate with it, and print plain text files to the printer. - - - See section Advanced Printer - Setup to find out how to print a variety of special file - formats, to print header pages, to print across a network, to - control access to printers, and to do printer accounting. - - - - - - Simple Printer Setup - - This section tells how to configure printer hardware and the LPD - software to use the printer. It teaches the basics: - - - - Section Hardware Setup - gives some hints on connecting the printer to a port on your - computer. - - + - Section Software Setup - shows how to setup the LPD spooler configuration file - /etc/printcap. + See section Advanced + Printer Setup to find out how to print a variety of + special file formats, to print header pages, to print across a + network, to control access to printers, and to do printer + accounting. - - If you are setting up a printer that uses a network protocol to - accept data to print instead of a serial or parallel interface, see - Printers With Networked - Data Stream Interaces. - - Although this section is called “Simple Printer Setup,” - it is actually fairly complex. Getting the printer to work with your - computer and the LPD spooler is the hardest part. The advanced options - like header pages and accounting are fairly easy once you get the - printer working. - - - Hardware Setup - - This section tells about the various ways you can connect a - printer to your PC. It talks about the kinds of ports and cables, and - also the kernel configuration you may need to enable FreeBSD to speak - to the printer. - - If you have already connected your printer and have successfully - printed with it under another operating system, you can probably skip - to section Software - Setup. - - - Ports and Cables - Nearly all printers you can get for a PC today support one or - both of the following interfaces: - - - - Serial interfaces use a serial port on - your computer to send data to the printer. Serial interfaces - are common in the computer industry and cables are readily - available and also easy to construct. Serial interfaces - sometimes need special cables and might require you to configure - somewhat complex communications options. - - - - Parallel interfaces use a parallel port - on your computer to send data to the printer. Parallel - interfaces are common in the PC market. Cables are readily - available but more difficult to construct by hand. There are - usually no communications options with parallel interfaces, - making their configuration exceedingly simple. - - Parallel interfaces are sometimes known as - “Centronics” interfaces, named after the connector - type on the printer. - - - - In general, serial interfaces are slower than parallel - interfaces. Parallel interfaces usually offer just one-way - communication (computer to printer) while serial gives you two-way. - Many newer parallel ports can also receive data from the printer, - but only few printers need to send data back to the computer. And - FreeBSD does not support two-way parallel communication yet. - - Usually, the only time you need two-way communication with the - printer is if the printer speaks PostScript. PostScript printers - can be very verbose. In fact, PostScript jobs are actually programs - sent to the printer; they need not produce paper at all and may - return results directly to the computer. PostScript also uses - two-way communication to tell the computer about problems, such as - errors in the PostScript program or paper jams. Your users may be - appreciative of such information. Furthermore, the best way to do - effective accounting with a PostScript printer requires two-way - communication: you ask the printer for its page count (how many - pages it has printed in its lifetime), then send the user's job, - then ask again for its page count. Subtract the two values and you - know how much paper to charge the user. - - So, which interface should you use? - - - - If you need two-way communication, use a serial port. - FreeBSD does not yet support two-way communication over a - parallel port. - - - - If you do not need two-way communication and can pick - parallel or serial, prefer the parallel interface. It keeps a - serial port free for other peripherals—such as a terminal - or a modem—and is faster most of the time. It is also - easier to configure. - - - - Finally, use whatever works. - - - - - - Parallel Ports + + Simple Printer Setup - To hook up a printer using a parallel interface, connect the - Centronics cable between the printer and the computer. The - instructions that came with the printer, the computer, or both - should give you complete guidance. - - Remember which parallel port you used on the computer. The - first parallel port is /dev/lpt0 to FreeBSD; - the second is /dev/lpt1, and so on. - + This section tells how to configure printer hardware and the + LPD software to use the printer. It teaches the basics: + + + + Section Hardware + Setup gives some hints on connecting the printer to a + port on your computer. + + + + Section Software + Setup shows how to setup the LPD spooler configuration + file (/etc/printcap). + + + + If you are setting up a printer that uses a network protocol + to accept data to print instead of a serial or parallel interface, + see Printers With + Networked Data Stream Interaces. + + Although this section is called “Simple Printer + Setup”, it is actually fairly complex. Getting the printer + to work with your computer and the LPD spooler is the hardest + part. The advanced options like header pages and accounting are + fairly easy once you get the printer working. + + + Hardware Setup + + This section tells about the various ways you can connect a + printer to your PC. It talks about the kinds of ports and + cables, and also the kernel configuration you may need to enable + FreeBSD to speak to the printer. + + If you have already connected your printer and have + successfully printed with it under another operating system, you + can probably skip to section Software Setup. + + + Ports and Cables + + Nearly all printers you can get for a PC today support one + or both of the following interfaces: + + + + Serial interfaces use a serial + port on your computer to send data to the printer. Serial + interfaces are common in the computer industry and cables + are readily available and also easy to construct. Serial + interfaces sometimes need special cables and might require + you to configure somewhat complex communications + options. + + + + Parallel interfaces use a + parallel port on your computer to send data to the + printer. Parallel interfaces are common in the PC market. + Cables are readily available but more difficult to + construct by hand. There are usually no communications + options with parallel interfaces, making their + configuration exceedingly simple. + + Parallel interfaces are sometimes known as + “Centronics” interfaces, named after the + connector type on the printer. + + + + In general, serial interfaces are slower than parallel + interfaces. Parallel interfaces usually offer just one-way + communication (computer to printer) while serial gives you + two-way. Many newer parallel ports can also receive data from + the printer, but only few printers need to send data back to + the computer. And FreeBSD does not support two-way parallel + communication yet. + + Usually, the only time you need two-way communication with + the printer is if the printer speaks PostScript. PostScript + printers can be very verbose. In fact, PostScript jobs are + actually programs sent to the printer; they need not produce + paper at all and may return results directly to the computer. + PostScript also uses two-way communication to tell the + computer about problems, such as errors in the PostScript + program or paper jams. Your users may be appreciative of such + information. Furthermore, the best way to do effective + accounting with a PostScript printer requires two-way + communication: you ask the printer for its page count (how + many pages it has printed in its lifetime), then send the + user's job, then ask again for its page count. Subtract the + two values and you know how much paper to charge the + user. + - - Serial Ports + + Parallel Ports + + To hook up a printer using a parallel interface, connect + the Centronics cable between the printer and the computer. + The instructions that came with the printer, the computer, or + both should give you complete guidance. + + Remember which parallel port you used on the computer. + The first parallel port is /dev/lpt0 to + FreeBSD; the second is /dev/lpt1, and so + on. + - To hook up a printer using a serial interface, connect the - proper serial cable between the printer and the computer. The - instructions that came with the printer, the computer, or both - should give you complete guidance. + + Serial Ports - If you are unsure what the “proper serial cable” is, - you may wish to try one of the following alternatives: + To hook up a printer using a serial interface, connect the + proper serial cable between the printer and the computer. The + instructions that came with the printer, the computer, or both + should give you complete guidance. - - - A modem cable connects each pin of the - connector on one end of the cable straight through to its - corresponding pin of the connector on the other end. This type - of cable is also known as a “DTE-to-DCE” - cable. - - - - A null-modem cable connects some pins - straight through, swaps others (send data to receive data, for - example), and shorts some internally in each connector hood. - This type of cable is also known as a “DTE-to-DTE” - cable. - - - - A serial printer cable, required for - some unusual printers, is like the null modem cable, but sends - some signals to their counterparts instead of being internally - shorted. - - - - You should also set up the communications parameters for the - printer, usually through front-panel controls or DIP switches on the - printer. Choose the highest bps (bits per second, sometimes - baud rate) rate that both your computer and the - printer can support. Choose 7 or 8 data bits; none, even, or odd - parity; and 1 or 2 stop bits. Also choose a flow control protocol: - either none, or XON/XOFF (also known as “in-band” or - “software”) flow control. Remember these settings for - the software configuration that follows. + If you are unsure what the “proper serial + cable” is, you may wish to try one of the following + alternatives: + + + + A modem cable connects each pin + of the connector on one end of the cable straight through + to its corresponding pin of the connector on the other + end. This type of cable is also known as a + “DTE-to-DCE” cable. + + + + A null-modem cable connects some + pins straight through, swaps others (send data to receive + data, for example), and shorts some internally in each + connector hood. This type of cable is also known as a + “DTE-to-DTE” cable. + + + + A serial printer cable, required + for some unusual printers, is like the null modem cable, + but sends some signals to their counterparts instead of + being internally shorted. + + + + You should also set up the communications parameters for + the printer, usually through front-panel controls or DIP + switches on the printer. Choose the highest + bps (bits per second, sometimes + baud rate) rate that both your computer + and the printer can support. Choose 7 or 8 data bits; none, + even, or odd parity; and 1 or 2 stop bits. Also choose a flow + control protocol: either none, or XON/XOFF (also known as + “in-band” or “software”) flow control. + Remember these settings for the software configuration that + follows. + - - - - Software Setup - - This section describes the software setup necessary to print - with the LPD spooling system in FreeBSD. - - Here is an outline of the steps involved: - - - - Configure your kernel, if necessary, for the port you are - using for the printer; section Kernel Configuration tells you - what you need to do. - - - - Set the communications mode for the parallel port, if you are - using a parallel port; section Setting the Communication - Mode for the Parallel Port gives details. - - - - Test if the operating system can send data to the printer. - Section Checking Printer + + + Software Setup + + This section describes the software setup necessary to print + with the LPD spooling system in FreeBSD. + + Here is an outline of the steps involved: + + + + Configure your kernel, if necessary, for the port you + are using for the printer; section Kernel Configuration tells + you what you need to do. + + + + Set the communications mode for the parallel port, if + you are using a parallel port; section Setting the + Communication Mode for the Parallel Port gives + details. + + + + Test if the operating system can send data to the printer. + Section Checking Printer Communications gives some suggestions on how to do - this. - - - - Set up LPD for the printer by modifying the file - /etc/printcap. Section The /etc/printcap File shows - you how. - - - - - Kernel Configuration - - The operating system kernel is compiled to work with a specific - set of devices. The serial or parallel interface for your printer - is a part of that set. Therefore, it might be necessary to add - support for an additional serial or parallel port if your kernel is - not already configured for one. - - To find out if the kernel you are currently using supports a - serial interface, type: - - &prompt.root; dmesg | grep sioN - - Where N is the number of the serial - port, starting from zero. If you see output similar to the - following: + this. + + + + Set up LPD for the printer by modifying the file + /etc/printcap. You will find out how + to do this later in this chapter. + + + + + Kernel Configuration + + The operating system kernel is compiled to work with a + specific set of devices. The serial or parallel interface for + your printer is a part of that set. Therefore, it might be + necessary to add support for an additional serial or parallel + port if your kernel is not already configured for one. - sio2 at 0x3e8-0x3ef irq 5 on isa + To find out if the kernel you are currently using supports + a serial interface, type: + + &prompt.root; dmesg | grep sioN + + Where N is the number of the + serial port, starting from zero. If you see output similar to + the following: + + sio2 at 0x3e8-0x3ef irq 5 on isa sio2: type 16550A - - then the kernel supports the port. - To find out if the kernel supports a parallel interface, - type: + then the kernel supports the port. - &prompt.root; dmesg | grep lptN - - Where N is the number of the parallel - port, starting from zero. If you see output similar to the - following lpt0 at 0x378-0x37f on isa then the - kernel supports the port. - - You might have to reconfigure your kernel in order for the - operating system to recognize and use the parallel or serial port - you are using for the printer. - - To add support for a serial port, see the section on kernel - configuration. To add support for a parallel port, see that section - and the section that follows. - - - Adding <filename>/dev</filename> Entries for the Ports - - Even though the kernel may support communication along a - serial or parallel port, you will still need a software interface - through which programs running on the system can send and receive - data. That is what entries in the /dev - directory are for. - - To add a /dev entry for a - port: - - - - Become root with the &man.su.1; command. Enter the root - password when prompted. - - - - Change to the /dev directory: - - &prompt.root; cd /dev - - - - - Type: - - &prompt.root; ./MAKEDEV port - - Where port is the device entry - for the port you want to make. Use lpt0 - for the first parallel port, lpt1 for the - second, and so on; use ttyd0 for the first - serial port, ttyd1 for the second, and so - on. - - - - Type: - - &prompt.root; ls -l port - - to make sure the device entry got created. - - + To find out if the kernel supports a parallel interface, + type: + + &prompt.root; dmesg | grep lptN + + Where N is the number of the + parallel port, starting from zero. If you see output similar + to the following lpt0 at 0x378-0x37f on isa + then the kernel supports the port. + + You might have to reconfigure your kernel in order for the + operating system to recognize and use the parallel or serial + port you are using for the printer. + + To add support for a serial port, see the section on + kernel configuration. To add support for a parallel port, see + that section and the section that + follows. + + + + Adding <filename>/dev</filename> Entries for the + Ports + + Even though the kernel may support communication along a + serial or parallel port, you will still need a software + interface through which programs running on the system can + send and receive data. That is what entries in the + /dev directory are for. + + To add a /dev entry for a + port: + + + + Become root with the &man.su.1; command. Enter the + root password when prompted. + + + + Change to the /dev + directory: + + &prompt.root; cd /dev + + + + Type: + + &prompt.root; ./MAKEDEV port + + Where port is the device + entry for the port you want to make. Use + lpt0 for the first parallel port, + lpt1 for the second, and so on; use + ttyd0 for the first serial port, + ttyd1 for the second, and so on. + + + + Type: + + &prompt.root; ls -l port + + to make sure the device entry got created. + + - Setting the Communication Mode for the Parallel Port - + Setting the Communication Mode for the Parallel + Port + When you are using the parallel interface, you can choose whether FreeBSD should use interrupt-driven or polled communication with the printer. - + - The interrupt-driven method is the - default with the GENERIC kernel. With this method, the - operating system uses an IRQ line to determine when the - printer is ready for data. + The interrupt-driven method is + the default with the GENERIC kernel. With this method, + the operating system uses an IRQ line to determine when + the printer is ready for data. - + The polled method directs the - operating system to repeatedly ask the printer if it is ready - for more data. When it responds ready, the kernel sends more - data. + operating system to repeatedly ask the printer if it is + ready for more data. When it responds ready, the kernel + sends more data. - - The interrupt-driven method is somewhat faster but uses up a - precious IRQ line. You should use whichever one works. - + + The interrupt-driven method is somewhat faster but uses up + a precious IRQ line. You should use whichever one + works. + You can set the communications mode in two ways: by configuring the kernel or by using the &man.lptcontrol.8; program. - - To set the communications mode by configuring the - kernel: - + + To set the communications mode by configuring + the kernel: + - Edit your kernel configuration file. Look for or add an - lpt0 entry. If you are setting up the - second parallel port, use lpt1 instead. - Use lpt2 for the third port, and so - on. - + Edit your kernel configuration file. Look for or add + an lpt0 entry. If you are setting up + the second parallel port, use lpt1 + instead. Use lpt2 for the third port, + and so on. + If you want interrupt-driven mode, add the irq specifier: - + device lpt0 at isa? port? tty irq N vector lptintr - Where N is the IRQ number - for your computer's parallel port. + Where N is the IRQ + number for your computer's parallel port. - + If you want polled mode, do not add the irq specifier: - + device lpt0 at isa? port? tty vector lptintr - + Save the file. Then configure, build, and install the - kernel, then reboot. See kernel - configuration for more details. + kernel, then reboot. See kernel configuration for + more details. - + To set the communications mode with - &man.lptcontrol.8;: - + &man.lptcontrol.8;: + Type: - + &prompt.root; lptcontrol -i -u N - + to set interrupt-driven mode for lptN. - + Type: - + &prompt.root; lptcontrol -p -u N - + to set polled-mode for lptN. - + You could put these commands in your - /etc/rc.local file to set the mode each time - your system boots. See &man.lptcontrol.8; for more + /etc/rc.local file to set the mode each + time your system boots. See &man.lptcontrol.8; for more information. Checking Printer Communications - - Before proceeding to configure the spooling system, you should - make sure the operating system can successfully send data to your - printer. It is a lot easier to debug printer communication and - the spooling system separately. - + + Before proceeding to configure the spooling system, you + should make sure the operating system can successfully send + data to your printer. It is a lot easier to debug printer + communication and the spooling system separately. + To test the printer, we will send some text to it. For printers that can immediately print characters sent to them, the program &man.lptest.1; is perfect: it generates all 96 printable ASCII characters in 96 lines. - - For a PostScript (or other language-based) printer, we will - need a more sophisticated test. A small PostScript program, such - as the following, will suffice: + + For a PostScript (or other language-based) printer, we + will need a more sophisticated test. A small PostScript + program, such as the following, will suffice: %!PS 100 100 moveto 300 300 lineto stroke 310 310 moveto /Helvetica findfont 12 scalefont setfont (Is this thing working?) show showpage - + - When this document refers to a printer language, I am - assuming a language like PostScript, and not Hewlett Packard's - PCL. Although PCL has great functionality, you can intermingle - plain text with its escape sequences. PostScript cannot directly - print plain text, and that is the kind of printer language for - which we must make special accommodations. - - + When this document refers to a printer language, it is + assuming a language like PostScript, and not Hewlett + Packard's PCL. Although PCL has great functionality, you + can intermingle plain text with its escape sequences. + PostScript cannot directly print plain text, and that is the + kind of printer language for which we must make special + accommodations. + + Checking a Parallel Printer - + This section tells you how to check if FreeBSD can - communicate with a printer connected to a parallel port. - + communicate with a printer connected to a parallel + port. + To test a printer on a parallel - port: - + port: + Become root with &man.su.1;. - + Send data to the printer. If the printer can print plain text, then use - &man.lptest.1;. Type: - + &man.lptest.1;. Type: + &prompt.root; lptest > /dev/lptN - - Where N is the number of - the parallel port, starting from zero. + + Where N is the number + of the parallel port, starting from zero. - + If the printer understands PostScript or other printer language, then send a small program to the printer. Type: - + &prompt.root; cat > /dev/lptN - + Then, line by line, type the program - carefully as you cannot edit a line - once you have pressed RETURN or ENTER. When you have - finished entering the program, press CONTROL+D, or - whatever your end of file key is. - - Alternatively, you can put the program in a file and - type: - + carefully as you cannot edit a + line once you have pressed RETURN + or ENTER. When you have finished + entering the program, press + CONTROL+D, or whatever your end + of file key is. + + Alternatively, you can put the program in a file + and type: + &prompt.root; cat file > /dev/lptN - - Where file is the name of - the file containing the program you want to send to the - printer. + + Where file is the + name of the file containing the program you want to + send to the printer. - - You should see something print. Do not worry if the text - does not look right; we will fix such things later. + + You should see something print. Do not worry if the + text does not look right; we will fix such things + later. - + Checking a Serial Printer - + This section tells you how to check if FreeBSD can communicate with a printer on a serial port. - + To test a printer on a serial - port: - + port: + Become root with &man.su.1;. - + - Edit the file /etc/remote. Add the - following entry: - + Edit the file /etc/remote. Add + the following entry: + printer:dv=/dev/port:br#bps-rate:pa=parity Where port is the device entry for the serial port (ttyd0, ttyd1, etc.), - bps-rate is the bits-per-second - rate at which the printer communicates, and - parity is the parity required by - the printer (either even, + bps-rate is the + bits-per-second rate at which the printer communicates, + and parity is the parity + required by the printer (either even, odd, none, or zero). - - Here is a sample entry for a printer connected via a - serial line to the third serial port at 19200 bps with no - parity: - + + Here is a sample entry for a printer connected via + a serial line to the third serial port at 19200 bps with + no parity: + printer:dv=/dev/ttyd2:br#19200:pa=none - + - Connect to the printer with &man.tip.1;. Type: - + Connect to the printer with &man.tip.1;. + Type: + &prompt.root; tip printer - + If this step does not work, edit the file /etc/remote again and try using /dev/cuaaN instead of /dev/ttydN. - + Send data to the printer. If the printer can print plain text, then use - &man.lptest.1;. Type: - + &man.lptest.1;. Type: + ~$lptest - + If the printer understands PostScript or other printer language, then send a small program to the - printer. Type the program, line by line, very - carefully as backspacing or other editing - keys may be significant to the printer. You may also - need to type a special end-of-file key for the printer - so it knows it received the whole program. For - PostScript printers, press CONTROL+D. - - Alternatively, you can put the program in a file and - type: - + printer. Type the program, line by line, + very carefully as backspacing + or other editing keys may be significant to the + printer. You may also need to type a special + end-of-file key for the printer so it knows it + received the whole program. For PostScript + printers, press CONTROL+D. + + Alternatively, you can put the program in a file + and type: + ~>file - - Where file is the name of - the file containing the program. After - &man.tip.1; sends the file, press any required + + Where file is the + name of the file containing the program. After + &man.tip.1; sends the file, press any required end-of-file key. - - You should see something print. Do not worry if the text - does not look right; we will fix that later. + + You should see something print. Do not worry if the + text does not look right; we will fix that later. - + Enabling the Spooler: The <filename>/etc/printcap</filename> File At this point, your printer should be hooked up, your kernel - configured to communicate with it (if necessary), and you have been - able to send some simple data to the printer. Now, we are ready to - configure LPD to control access to your printer. - + configured to communicate with it (if necessary), and you have + been able to send some simple data to the printer. Now, we are + ready to configure LPD to control access to your printer. + You configure LPD by editing the file - /etc/printcap. The LPD spooling system reads - this file each time the spooler is used, so updates to the file take - immediate effect. - - The format of the &man.printcap.5; file is straightforward. Use - your favorite text editor to make changes to + /etc/printcap. The LPD spooling system + reads this file each time the spooler is used, so updates to the + file take immediate effect. + + The format of the &man.printcap.5; file is straightforward. + Use your favorite text editor to make changes to /etc/printcap. The format is identical to other capability files like /usr/share/misc/termcap and - /etc/remote. For complete information about - the format, see the &man.cgetent.3;. - + /etc/remote. For complete information + about the format, see the &man.cgetent.3;. + The simple spooler configuration consists of the following steps: - Pick a name (and a few convenient aliases) for the printer, - and put them in the /etc/printcap file; see - Naming the - Printer. + Pick a name (and a few convenient aliases) for the + printer, and put them in the + /etc/printcap file; see the + Naming the Printer + section for more information on naming. - + - Turn off header pages (which are on by default) by inserting - the sh capability; see Suppressing Header - Pages. + Turn off header pages (which are on by default) by + inserting the sh capability; see the + Suppressing Header + Pages section for more information. - + - Make a spooling directory, and specify its location with the - sd capability; see Making the Spooling - Directory. + Make a spooling directory, and specify its location with + the sd capability; see the Making the Spooling + Directory section for more information. - + Set the /dev entry to use for the - printer, and note it in /etc/printcap with - the lp capability; see Identifying the Printer - Device. Also, if the printer is on a serial port, set - up the communication parameters with the fs, - fc, xs, and - xc capabilities; see Configuring Spooler - Communications Parameters. + printer, and note it in /etc/printcap + with the lp capability; see the Identifying the Printer + Device for more information. Also, if the printer is + on a serial port, set up the communication parameters with + the fs, fc, + xs, and xc + capabilities; which is discussed in the Configuring Spooler + Communications Parameters section. - + - Install a plain text input filter; see Installing the Text - Filter + Install a plain text input filter; see the Installing the Text + Filter section for details. - + Test the setup by printing something with the - &man.lpr.1; command; see Trying It Out and Troubleshooting. + &man.lpr.1; command. More details are available in the + Trying It Out and + Troubleshooting + sections. - Language-based printers, such as PostScript printers, cannot - directly print plain text. The simple setup outlined above and - described in the following sections assumes that if you are - installing such a printer you will print only files that the - printer can understand. + Language-based printers, such as PostScript printers, + cannot directly print plain text. The simple setup outlined + above and described in the following sections assumes that if + you are installing such a printer you will print only files + that the printer can understand. - Users often expect that they can print plain text to any of the - printers installed on your system. Programs that interface to LPD - to do their printing usually make the same assumption. If you are - installing such a printer and want to be able to print jobs in the - printer language and print plain text jobs, you - are strongly urged to add an additional step to the simple setup - outlined above: install an automatic plain-text-to-PostScript (or - other printer language) conversion program. Section Accommodating Plain Text - Jobs on PostScript Printers tells how to do this. - + Users often expect that they can print plain text to any of + the printers installed on your system. Programs that interface + to LPD to do their printing usually make the same assumption. + If you are installing such a printer and want to be able to + print jobs in the printer language and + print plain text jobs, you are strongly urged to add an + additional step to the simple setup outlined above: install an + automatic plain-text-to-PostScript (or other printer language) + conversion program. The section entitled Accommodating Plain + Text Jobs on PostScript Printers tells how to do + this. + Naming the Printer - - The first (easy) step is to pick a name for your printer. It - really does not matter whether you choose functional or whimsical - names since you can also provide a number aliases for the - printer. - + + The first (easy) step is to pick a name for your printer + It really does not matter whether you choose functional or + whimsical names since you can also provide a number aliases + for the printer. + At least one of the printers specified in the /etc/printcap should have the alias - lp. This is the default printer's name. If - users do not have the PRINTER environment variable - nor specify a printer name on the command line of any of the LPD - commands, then lp will be the default printer - they get to use. - + lp. This is the default printer's name. + If users do not have the PRINTER environment + variable nor specify a printer name on the command line of any + of the LPD commands, then lp will be the + default printer they get to use. + Also, it is common practice to make the last alias for a - printer be a full description of the printer, including make and - model. - - Once you have picked a name and some common aliases, put them - in the /etc/printcap file. The name of the - printer should start in the leftmost column. Separate each alias - with a vertical bar and put a colon after the last alias. - + printer be a full description of the printer, including make + and model. + + Once you have picked a name and some common aliases, put + them in the /etc/printcap file. The name + of the printer should start in the leftmost column. Separate + each alias with a vertical bar and put a colon after the last + alias. + In the following example, we start with a skeletal - /etc/printcap that defines two printers (a - Diablo 630 line printer and a Panasonic KX-P4455 PostScript laser - printer): + /etc/printcap that defines two printers + (a Diablo 630 line printer and a Panasonic KX-P4455 PostScript + laser printer): # # /etc/printcap for host rose # rattan|line|diablo|lp|Diablo 630 Line Printer: bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4: - + In this example, the first printer is named rattan and has as aliases line, diablo, lp, and Diablo 630 Line - Printer. Since it has the alias - lp, it is also the default printer. The second - is named bamboo, and has as aliases + Printer. Since it has the alias + lp, it is also the default printer. The + second is named bamboo, and has as aliases ps, PS, S, panasonic, and Panasonic KX-P4455 PostScript v51.4. Suppressing Header Pages - + The LPD spooling system will by default print a - header page for each job. The header page - contains the user name who requested the job, the host from which - the job came, and the name of the job, in nice large letters. - Unfortunately, all this extra text gets in the way of debugging - the simple printer setup, so we will suppress header pages. - + header page for each job. The header + page contains the user name who requested the job, the host + from which the job came, and the name of the job, in nice + large letters. Unfortunately, all this extra text gets in the + way of debugging the simple printer setup, so we will suppress + header pages. + To suppress header pages, add the sh capability to the entry for the printer in - /etc/printcap. Here is the example + /etc/printcap. Here is an example /etc/printcap with sh added: - + # # /etc/printcap for host rose - no header pages anywhere # rattan|line|diablo|lp|Diablo 630 Line Printer:\ :sh: bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4:\ :sh: - Note how we used the correct format: the first line starts in - the leftmost column, and subsequent lines are indented with a - single TAB. Every line in an entry except the last ends in a - backslash character. + Note how we used the correct format: the first line starts + in the leftmost column, and subsequent lines are indented with + a single TAB. Every line in an entry except the last ends in + a backslash character. Making the Spooling Directory - + The next step in the simple spooler setup is to make a - spooling directory, a directory where print - jobs reside until they are printed, and where a number of other - spooler support files live. - - Because of the variable nature of spooling directories, it is - customary to put these directories under - /var/spool. It is not necessary to backup - the contents of spooling directories, either. Recreating them is - as simple as running &man.mkdir.1;. - - It is also customary to make the directory with a name that is - identical to the name of the printer, as shown below: - + spooling directory, a directory where + print jobs reside until they are printed, and where a number + of other spooler support files live. + + Because of the variable nature of spooling directories, it + is customary to put these directories under + /var/spool. It is not necessary to + backup the contents of spooling directories, either. + Recreating them is as simple as running &man.mkdir.1;. + + It is also customary to make the directory with a name + that is identical to the name of the printer, as shown + below: + &prompt.root; mkdir /var/spool/printer-name - - However, if you have a lot of printers on your network, you - might want to put the spooling directories under a single - directory that you reserve just for printing with LPD. We will do - this for our two example printers rattan and + + However, if you have a lot of printers on your network, + you might want to put the spooling directories under a single + directory that you reserve just for printing with LPD. We + will do this for our two example printers + rattan and bamboo: - + &prompt.root; mkdir /var/spool/lpd &prompt.root; mkdir /var/spool/lpd/rattan &prompt.root; mkdir /var/spool/lpd/bamboo - + - If you are concerned about the privacy of jobs that users - print, you might want to protect the spooling directory so it is - not publicly accessible. Spooling directories should be owned - and be readable, writable, and searchable by user daemon and - group daemon, and no one else. We will do this for our example - printers: - + If you are concerned about the privacy of jobs that + users print, you might want to protect the spooling + directory so it is not publicly accessible. Spooling + directories should be owned and be readable, writable, and + searchable by user daemon and group daemon, and no one else. + We will do this for our example printers: + &prompt.root; chown daemon.daemon /var/spool/lpd/rattan &prompt.root; chown daemon.daemon /var/spool/lpd/bamboo &prompt.root; chmod 770 /var/spool/lpd/rattan &prompt.root; chmod 770 /var/spool/lpd/bamboo - - Finally, you need to tell LPD about these directories using - the /etc/printcap file. You specify the - pathname of the spooling directory with the sd - capability: + + Finally, you need to tell LPD about these directories + using the /etc/printcap file. You + specify the pathname of the spooling directory with the + sd capability: # # /etc/printcap for host rose - added spooling directories # rattan|line|diablo|lp|Diablo 630 Line Printer:\ :sh:sd=/var/spool/lpd/rattan: bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4:\ :sh:sd=/var/spool/lpd/bamboo: - Note that the name of the printer starts in the first column - but all other entries describing the printer should be indented - with a tab and each line escaped with a backslash. - + Note that the name of the printer starts in the first + column but all other entries describing the printer should be + indented with a tab and each line escaped with a + backslash. + If you do not specify a spooling directory with sd, the spooling system will use /var/spool/lpd as a default. - + Identifying the Printer Device - - In section Adding /dev - Entries for the Ports, we identified which entry in the + + In the Adding + /dev Entries for the Ports + section, we identified which entry in the /dev directory FreeBSD will use to - communicate with the printer. Now, we tell LPD that information. - When the spooling system has a job to print, it will open the - specified device on behalf of the filter program (which is - responsible for passing data to the printer). - + communicate with the printer. Now, we tell LPD that + information. When the spooling system has a job to print, it + will open the specified device on behalf of the filter program + (which is responsible for passing data to the printer). + List the /dev entry pathname in the /etc/printcap file using the lp capability. - + In our running example, let us assume that rattan is on the first parallel port, and - bamboo is on a sixth serial port; here are the - additions to /etc/printcap: - + bamboo is on a sixth serial port; here are + the additions to /etc/printcap: + # # /etc/printcap for host rose - identified what devices to use # rattan|line|diablo|lp|Diablo 630 Line Printer:\ :sh:sd=/var/spool/lpd/rattan:\ :lp=/dev/lpt0: bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4:\ :sh:sd=/var/spool/lpd/bamboo:\ :lp=/dev/ttyd5: - - If you do not specify the lp capability for - a printer in your /etc/printcap file, LPD - uses /dev/lp as a default. + + If you do not specify the lp capability + for a printer in your /etc/printcap file, + LPD uses /dev/lp as a default. /dev/lp currently does not exist in FreeBSD. - - If the printer you are installing is connected to a parallel - port, skip to the section Installing the Text Filter. - Otherwise, be sure to follow the instructions in the next - section. + + If the printer you are installing is connected to a + parallel port, skip to the section entitled, Installing the Text + Filter. Otherwise, be sure to follow the instructions + in the next section. - + Configuring Spooler Communication Parameters - + For printers on serial ports, LPD can set up the bps rate, - parity, and other serial communication parameters on behalf of the - filter program that sends data to the printer. This is + parity, and other serial communication parameters on behalf of + the filter program that sends data to the printer. This is advantageous since: - + It lets you try different communication parameters by - simply editing the /etc/printcap file; - you do not have to recompile the filter program. + simply editing the /etc/printcap + file; you do not have to recompile the filter + program. - + It enables the spooling system to use the same filter - program for multiple printers which may have different serial - communication settings. + program for multiple printers which may have different + serial communication settings. - The following /etc/printcap capabilities - control serial communication parameters of the device listed in - the lp capability: + The following /etc/printcap + capabilities control serial communication parameters of the + device listed in the lp capability: br#bps-rate Sets the communications speed of the device to bps-rate, where - bps-rate can be 50, 75, 110, 134, - 150, 200, 300, 600, 1200, 1800, 2400, 4800, 9600, 19200, or - 38400 bits-per-second. + bps-rate can be 50, 75, 110, + 134, 150, 200, 300, 600, 1200, 1800, 2400, 4800, 9600, + 19200, or 38400 bits-per-second. - + fc#clear-bits - + Clears the flag bits clear-bits in the - sgttyb structure after opening - the device. + sgttyb structure after + opening the device. - + fs#set-bits - + - Sets the flag bits set-bits - in the sgttyb structure. + Sets the flag bits + set-bits in the + sgttyb structure. - + xc#clear-bits - + Clears local mode bits clear-bits after opening the device. - + xs#set-bits - + Sets local mode bits set-bits. - + For more information on the bits for the fc, fs, - xc, and xs capabilities, see - the file + xc, and xs capabilities, + see the file /usr/include/sys/ioctl_compat.h. - + When LPD opens the device specified by the - lp capability, it reads the flag bits in the - sgttyb structure; it clears any bits in the - fc capability, then sets bits in the + lp capability, it reads the flag bits in + the sgttyb structure; it clears any bits in + the fc capability, then sets bits in the fs capability, then applies the resultant - setting. It does the same for the local mode bits as well. - - Let us add to our example printer on the sixth serial port. - We will set the bps rate to 38400. For the flag bits, we will set - the TANDEM, ANYP, LITOUT, FLUSHO, and PASS8 flags. For the local - mode bits, we will set the LITOUT and PASS8 flags: + setting. It does the same for the local mode bits as + well. + + Let us add to our example printer on the sixth serial + port. We will set the bps rate to 38400. For the flag bits, + we will set the TANDEM, + ANYP, LITOUT, + FLUSHO, and PASS8 flags. + For the local mode bits, we will set the + LITOUT and PASS8 + flags: bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4:\ :sh:sd=/var/spool/lpd/bamboo:\ :lp=/dev/ttyd5:fs#0x82000c1:xs#0x820: Installing the Text Filter - - We are now ready to tell LPD what text filter to use to send - jobs to the printer. A text filter, also - known as an input filter, is a program that - LPD runs when it has a job to print. When LPD runs the text - filter for a printer, it sets the filter's standard input to the - job to print, and its standard output to the printer device - specified with the lp capability. The filter - is expected to read the job from standard input, perform any - necessary translation for the printer, and write the results to - standard output, which will get printed. For more information on - the text filter, see section Filters. - - For our simple printer setup, the text filter can be a small - shell script that just executes /bin/cat to - send the job to the printer. FreeBSD comes with another filter - called lpf that handles backspacing and - underlining for printers that might not deal with such character - streams well. And, of course, you can use any other filter - program you want. The filter lpf is described - in detail in section lpf: a - Text Filter. - + + We are now ready to tell LPD what text filter to use to + send jobs to the printer. A text filter, + also known as an input filter, is a + program that LPD runs when it has a job to print. When LPD + runs the text filter for a printer, it sets the filter's + standard input to the job to print, and its standard output to + the printer device specified with the lp + capability. The filter is expected to read the job from + standard input, perform any necessary translation for the + printer, and write the results to standard output, which will + get printed. For more information on the text filter, see + the Filters + section. + + For our simple printer setup, the text filter can be a + small shell script that just executes + /bin/cat to send the job to the printer. + FreeBSD comes with another filter called + lpf that handles backspacing and + underlining for printers that might not deal with such + character streams well. And, of course, you can use any other + filter program you want. The filter lpf is + described in detail in section entitled lpf: a Text + Filter. + First, let us make the shell script - /usr/local/libexec/if-simple be a simple text - filter. Put the following text into that file with your favorite - text editor: - + /usr/local/libexec/if-simple be a simple + text filter. Put the following text into that file with your + favorite text editor: + #!/bin/sh # # if-simple - Simple text input filter for lpd # Installed in /usr/local/libexec/if-simple # # Simply copies stdin to stdout. Ignores all filter arguments. /bin/cat && exit 0 exit 2 - + Make the file executable: - + &prompt.root; chmod 555 /usr/local/libexec/if-simple - + And then tell LPD to use it by specifying it with the if capability in /etc/printcap. We will add it to the two printers we have so far in the example /etc/printcap: - + # # /etc/printcap for host rose - added text filter # rattan|line|diablo|lp|Diablo 630 Line Printer:\ :sh:sd=/var/spool/lpd/rattan:\ :lp=/dev/lpt0:\ :if=/usr/local/libexec/if-simple: bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4:\ :sh:sd=/var/spool/lpd/bamboo:\ :lp=/dev/ttyd5:fs#0x82000e1:xs#0x820:\ :if=/usr/local/libexec/if-simple: Trying It Out - + You have reached the end of the simple LPD setup. - Unfortunately, congratulations are not quite yet in order, since - we still have to test the setup and correct any problems. To test - the setup, try printing something. To print with the LPD system, - you use the command &man.lpr.1;, + Unfortunately, congratulations are not quite yet in order, + since we still have to test the setup and correct any + problems. To test the setup, try printing something. To + print with the LPD system, you use the command &man.lpr.1;, which submits a job for printing. - - You can combine &man.lpr.1; with the &man.lptest.1; program, - introduced in section Checking - Printer Communications to generate some test text. + + You can combine &man.lpr.1; with the &man.lptest.1; + program, introduced in section Checking Printer + Communications to generate some test text. To test the simple LPD setup: - + Type: - + &prompt.root; lptest 20 5 | lpr -Pprinter-name - Where printer-name is a the name of - a printer (or an alias) specified in - /etc/printcap. To test the default printer, - type &man.lpr.1; without any - argument. Again, if you are testing a printer - that expects PostScript, send a PostScript program in that - language instead of using &man.lptest.1;. You can do so by - putting the program in a file and typing lpr - file. - - For a PostScript printer, you should get the results of the - program. If you are using &man.lptest.1;, then your results - should look like the following: + Where printer-name is a the + name of a printer (or an alias) specified in + /etc/printcap. To test the default + printer, type &man.lpr.1; without any + argument. Again, if you are testing a printer that expects + PostScript, send a PostScript program in that language instead + of using &man.lptest.1;. You can do so by putting the program + in a file and typing lpr + file. + + For a PostScript printer, you should get the results of + the program. If you are using &man.lptest.1;, then your + results should look like the following: - + !"#$%&'()*+,-./01234 "#$%&'()*+,-./012345 #$%&'()*+,-./0123456 $%&'()*+,-./01234567 %&'()*+,-./012345678 - - To further test the printer, try downloading larger programs - (for language-based printers) or running &man.lptest.1; with - different arguments. For example, lptest 80 60 - will produce 60 lines of 80 characters each. - - If the printer did not work, see the next section, Troubleshooting. + + To further test the printer, try downloading larger + programs (for language-based printers) or running + &man.lptest.1; with different arguments. For example, + lptest 80 60 will produce 60 lines of 80 + characters each. + + If the printer did not work, see the Troubleshooting + section. + + + + + + Advanced Printer Setup + + This section describes filters for printing specially formatted + files, header pages, printing across networks, and restricting and + accounting for printer usage. - - Troubleshooting - - After performing the simple test with &man.lptest.1;, you - might have gotten one of the following results instead of the - correct printout: - - - - It worked, after awhile; or, it did not eject a full - sheet. - - - The printer printed the above, but it sat for awhile and - did nothing. In fact, you might have needed to press a - PRINT REMAINING or FORM FEED button on the printer to get - any results to appear. - - If this is the case, the printer was probably waiting to - see if there was any more data for your job before it - printed anything. To fix this problem, you can have the - text filter send a FORM FEED character (or whatever is - necessary) to the printer. This is usually sufficient to - have the printer immediately print any text remaining in its - internal buffer. It is also useful to make sure each print - job ends on a full sheet, so the next job does not start - somewhere on the middle of the last page of the previous - job. - - The following replacement for the shell script - /usr/local/libexec/if-simple prints a - form feed after it sends the job to the printer: + + Filters + + Although LPD handles network protocols, queuing, access control, + and other aspects of printing, most of the real + work happens in the filters. Filters are + programs that communicate with the printer and handle its device + dependencies and special requirements. In the simple printer setup, + we installed a plain text filter—an extremely simple one that + should work with most printers (section Installing the Text + Filter). + + However, in order to take advantage of format conversion, printer + accounting, specific printer quirks, and so on, you should understand + how filters work. It will ultimately be the filter's responsibility + to handle these aspects. And the bad news is that most of the time + you have to provide filters yourself. The good + news is that many are generally available; when they are not, they are + usually easy to write. + + Also, FreeBSD comes with one, + /usr/libexec/lpr/lpf, that works with many + printers that can print plain text. (It handles backspacing and tabs + in the file, and does accounting, but that is about all it does.) + There are also several filters and filter components in the FreeBSD + ports collection. + + Here is what you will find in this section: + + + + Section How Filters + Work, tries to give an overview of a filter's role in the + printing process. You should read this section to get an + understanding of what is happening “under the hood” + when LPD uses filters. This knowledge could help you anticipate + and debug problems you might encounter as you install more and + more filters on each of your printers. + + + + LPD expects every printer to be able to print plain text by + default. This presents a problem for PostScript (or other + language-based printers) which cannot directly print plain text. + Section Accommodating + Plain Text Jobs on PostScript Printers tells you what you + should do to overcome this problem. I recommend reading this + section if you have a PostScript printer. + + + + PostScript is a popular output format for many programs. Even + some people (myself included) write PostScript code directly. But + PostScript printers are expensive. Section Simulating PostScript on + Non-PostScript Printers tells how you can further modify + a printer's text filter to accept and print PostScript data on a + non-PostScript printer. I recommend reading + this section if you do not have a PostScript printer. + + + + Section Conversion + Filters tells about a way you can automate the conversion + of specific file formats, such as graphic or typesetting data, + into formats your printer can understand. After reading this + section, you should be able to set up your printers such that + users can type lpr -t to print troff data, or + lpr -d to print TeX DVI data, or lpr + -v to print raster image data, and so forth. I + recommend reading this section. + + + + Section Output + Filters tells all about a not often used feature of LPD: + output filters. Unless you are printing header pages (see Header Pages), + you can probably skip that section altogether. + + + + Section lpf: a Text + Filter describes lpf, a fairly + complete if simple text filter for line printers (and laser + printers that act like line printers) that comes with FreeBSD. If + you need a quick way to get printer accounting working for plain + text, or if you have a printer which emits smoke when it sees + backspace characters, you should definitely consider + lpf. + + + + + How Filters Work + + As mentioned before, a filter is an executable program started + by LPD to handle the device-dependent part of communicating with the + printer. + + When LPD wants to print a file in a job, it starts a filter + program. It sets the filter's standard input to the file to print, + its standard output to the printer, and its standard error to the + error logging file (specified in the lf + capability in /etc/printcap, or + /dev/console by default). + + Which filter LPD starts and the filter's arguments depend on + what is listed in the /etc/printcap file and + what arguments the user specified for the job on the + &man.lpr.1; command line. For example, if the user typed + lpr -t, LPD would start the troff filter, listed + in the tf capability for the destination printer. + If the user wanted to print plain text, it would start the + if filter (this is mostly true: see Output Filters for + details). + + There are three kinds of filters you can specify in + /etc/printcap: + + + + The text filter, confusingly called the + input filter in LPD documentation, handles + regular text printing. Think of it as the default filter. LPD + expects every printer to be able to print plain text by default, + and it is the text filter's job to make sure backspaces, tabs, + or other special characters do not confuse the printer. If you + are in an environment where you have to account for printer + usage, the text filter must also account for pages printed, + usually by counting the number of lines printed and comparing + that to the number of lines per page the printer supports. The + text filter is started with the following argument list: + + + filter-name + -c + -wwidth + -llength + -iindent + -n login + -h host + acct-file + + + where + + + + + + + appears if the job's submitted with lpr + -l + + + + + width + + + is the value from the pw (page + width) capability specified in + /etc/printcap, default 132 + + + + + length + + + is the value from the pl (page + length) capability, default 66 + + + + + indent + + + is the amount of the indentation from lpr + -i, default 0 + + + + + login + + + is the account name of the user printing the + file + + + + + host + + + is the host name from which the job was + submitted + + + + + acct-file + + + is the name of the accounting file from the + af capability. + + + + + + + + A conversion filter converts a specific + file format into one the printer can render onto paper. For + example, ditroff typesetting data cannot be directly printed, + but you can install a conversion filter for ditroff files to + convert the ditroff data into a form the printer can digest and + print. Section Conversion + Filters tells all about them. Conversion filters also + need to do accounting, if you need printer accounting. + Conversion filters are started with the following arguments: + + + filter-name + -xpixel-width + -ypixel-height + -n login + -h host + acct-file + + + where pixel-width is the value + from the px capability (default 0) and + pixel-height is the value from the + py capability (default 0). + + + + The output filter is used only if there + is no text filter, or if header pages are enabled. In my + experience, output filters are rarely used. Section Output Filters describe + them. There are only two arguments to an output filter: + + + filter-name + -wwidth + -llength + + + which are identical to the text filters and + arguments. + + + + Filters should also exit with the + following exit status: + + + + exit 0 + + + If the filter printed the file successfully. + + + + + exit 1 + + + If the filter failed to print the file but wants LPD to + try to print the file again. LPD will restart a filter if it + exits with this status. + + + + + exit 2 + + + If the filter failed to print the file and does not want + LPD to try again. LPD will throw out the file. + + + + + The text filter that comes with the FreeBSD release, + /usr/libexec/lpr/lpf, takes advantage of the + page width and length arguments to determine when to send a form + feed and how to account for printer usage. It uses the login, host, + and accounting file arguments to make the accounting entries. + + If you are shopping for filters, see if they are LPD-compatible. + If they are, they must support the argument lists described above. + If you plan on writing filters for general use, then have them + support the same argument lists and exit codes. + + + + Accommodating Plain Text Jobs on PostScript Printers + + If you are the only user of your computer and PostScript (or + other language-based) printer, and you promise to never send plain + text to your printer and to never use features of various programs + that will want to send plain text to your printer, then you do not + need to worry about this section at all. + + But, if you would like to send both PostScript and plain text + jobs to the printer, then you are urged to augment your printer + setup. To do so, we have the text filter detect if the arriving job + is plain text or PostScript. All PostScript jobs must start with + %! (for other printer languages, see your printer + documentation). If those are the first two characters in the job, + we have PostScript, and can pass the rest of the job directly. If + those are not the first two characters in the file, then the filter + will convert the text into PostScript and print the result. + + How do we do this? + + If you have got a serial printer, a great way to do it is to + install lprps. lprps is a + PostScript printer filter which performs two-way communication with + the printer. It updates the printer's status file with verbose + information from the printer, so users and administrators can see + exactly what the state of the printer is (such as toner + low or paper jam). But more + importantly, it includes a program called psif + which detects whether the incoming job is plain text and calls + textps (another program that comes with + lprps) to convert it to PostScript. It then uses + lprps to send the job to the printer. + + lprps is part of the FreeBSD ports collection + (see The Ports Collection). You can + fetch, build and install it yourself, of course. After installing + lprps, just specify the pathname to the + psif program that is part of + lprps. If you installed lprps + from the ports collection, use the following in the serial + PostScript printer's entry in + /etc/printcap: + + +:if=/usr/local/libexec/psif: - + You should also specify the rw capability; + that tells LPD to open the printer in read-write mode. + + If you have a parallel PostScript printer (and therefore cannot + use two-way communication with the printer, which + lprps needs), you can use the following shell + script as the text filter: + + #!/bin/sh # -# if-simple - Simple text input filter for lpd -# Installed in /usr/local/libexec/if-simple +# psif - Print PostScript or plain text on a PostScript printer +# Script version; NOT the version that comes with lprps +# Installed in /usr/local/libexec/psif # -# Simply copies stdin to stdout. Ignores all filter arguments. -# Writes a form feed character (\f) after printing job. -/bin/cat && printf "\f" && exit 0 -exit 2 - - - - - It produced the “staircase effect.” - - - You got the following on paper: - - -!"#$%&'()*+,-./01234 - "#$%&'()*+,-./012345 - #$%&'()*+,-./0123456 - - You have become another victim of the - staircase effect, caused by conflicting - interpretations of what characters should indicate a - new-line. UNIX-style operating systems use a single - character: ASCII code 10, the line feed (LF). MS-DOS, OS/2, - and others uses a pair of characters, ASCII code 10 - and ASCII code 13 (the carriage return - or CR). Many printers use the MS-DOS convention for - representing new-lines. - - When you print with FreeBSD, your text used just the - line feed character. The printer, upon seeing a line feed - character, advanced the paper one line, but maintained the - same horizontal position on the page for the next character - to print. That is what the carriage return is for: to move - the location of the next character to print to the left edge - of the paper. - - Here is what FreeBSD wants your printer to do: - - - - - - Printer received CR - Printer prints CR - - - - Printer received LF - Printer prints CR + LF - - - - - - Here are some ways to achieve this: +read first_line +first_two_chars=`expr "$first_line" : '\(..\)'` - - - Use the printer's configuration switches or control - panel to alter its interpretation of these characters. - Check your printer's manual to find out how to do - this. - - - If you boot your system into other operating - systems besides FreeBSD, you may have to - reconfigure the printer to use a - an interpretation for CR and LF characters that those - other operating systems use. You might prefer one of - the other solutions, below. - - - - - Have FreeBSD's serial line driver automatically - convert LF to CR+LF. Of course, this works with - printers on serial ports only. To - enable this feature, set the CRMOD bit in - fs capability in the - /etc/printcap file for the - printer. - - - - Send an escape code to the - printer to have it temporarily treat LF characters - differently. Consult your printer's manual for escape - codes that your printer might support. When you find - the proper escape code, modify the text filter to send - the code first, then send the print job. - - Here is an example text filter for printers that - understand the Hewlett-Packard PCL escape codes. This - filter makes the printer treat LF characters as a LF and - CR; then it sends the job; then it sends a form feed to - eject the last page of the job. It should work with - nearly all Hewlett Packard printers. - - +if [ "$first_two_chars" = "%!" ]; then + # + # PostScript job, print it. + # + echo "$first_line" && cat && printf "\004" && exit 0 + exit 2 +else + # + # Plain text, convert it, then print it. + # + ( echo "$first_line"; cat ) | /usr/local/bin/textps && printf "\004" && exit 0 + exit 2 +fi + + In the above script, textps is a program we + installed separately to convert plain text to PostScript. You can + use any text-to-PostScript program you wish. The FreeBSD ports + collection (see The Ports Collection) + includes a full featured text-to-PostScript program called + a2ps that you might want to investigate. + + + + Simulating PostScript on Non-PostScript Printers + + PostScript is the de facto standard for + high quality typesetting and printing. PostScript is, however, an + expensive standard. Thankfully, Alladin + Enterprises has a free PostScript work-alike called + Ghostscript that runs with FreeBSD. + Ghostscript can read most PostScript files and can render their + pages onto a variety of devices, including many brands of + non-PostScript printers. By installing Ghostscript and using a + special text filter for your printer, you can make your + non-PostScript printer act like a real PostScript printer. + + Ghostscript should be in the FreeBSD ports collection, if you + would like to install it from there. You can fetch, build, and + install it quite easily yourself, as well. + + To simulate PostScript, we have the text filter detect if it is + printing a PostScript file. If it is not, then the filter will pass + the file directly to the printer; otherwise, it will use Ghostscript + to first convert the file into a format the printer will + understand. + + Here is an example: the following script is a text filter + for Hewlett Packard DeskJet 500 printers. For other printers, + substitute the argument to the + gs (Ghostscript) command. (Type gs + -h to get a list of devices the current installation of + Ghostscript supports.) + + #!/bin/sh # -# hpif - Simple text input filter for lpd for HP-PCL based printers -# Installed in /usr/local/libexec/hpif +# ifhp - Print Ghostscript-simulated PostScript on a DeskJet 500 +# Installed in /usr/local/libexec/hpif + # -# Simply copies stdin to stdout. Ignores all filter arguments. -# Tells printer to treat LF as CR+LF. Ejects the page when done. +# Treat LF as CR+LF: +# +printf "\033&k2G" || exit 2 -printf "\033&k2G" && cat && printf "\033&l0H" && exit 0 -exit 2 - - Here is an example - /etc/printcap from a host called - orchid. It has a single printer attached to its first - parallel port, a Hewlett Packard LaserJet 3Si named - teak. It is using the above script as - its text filter: - - # -# /etc/printcap for host orchid +# Read first two characters of the file # -teak|hp|laserjet|Hewlett Packard LaserJet 3Si:\ - :lp=/dev/lpt0:sh:sd=/var/spool/lpd/teak:mx#0:\ - :if=/usr/local/libexec/hpif: - - - - - - - It overprinted each line. - - - The printer never advanced a line. All of the lines of - text were printed on top of each other on one line. - - This problem is the “opposite” of the - staircase effect, described above, and is much rarer. - Somewhere, the LF characters that FreeBSD uses to end a line - are being treated as CR characters to return the print - location to the left edge of the paper, but not also down a - line. - - Use the printer's configuration switches or control - panel to enforce the following interpretation of LF and CR - characters: - - - - - - Printer receives - Printer prints - - - - - - CR - CR - - - - LF - CR + LF - - - - - - - - The printer lost characters. - - - While printing, the printer did not print a few - characters in each line. The problem might have gotten - worse as the printer ran, losing more and more - characters. - - The problem is that the printer cannot keep up with the - speed at which the computer sends data over a serial line. - (This problem should not occur with printers on parallel - ports.) There are two ways to overcome the problem: +read first_line +first_two_chars=`expr "$first_line" : '\(..\)'` - - - If the printer supports XON/XOFF flow control, have - FreeBSD use it by specifying the TANDEM bit in the - fs capability. - - - - If the printer supports carrier flow control, - specify the MDMBUF bit in the fs - capability. Make sure the cable connecting the printer - to the computer is correctly wired for carrier flow - control. - - - - If the printer does not support any flow control, - use some combination of the NLDELAY, TBDELAY, CRDELAY, - VTDELAY, and BSDELAY bits in the fs - capability to add appropriate delays to the stream of - data sent to the printer. - - - - - - - It printed garbage. - - - The printer printed what appeared to be random garbage, - but not the desired text. - - This is usually another symptom of incorrect - communications parameters with a serial printer. - Double-check the bps rate in the br - capability, and the parity bits in the fs - and fc capabilities; make sure the - printer is using the same settings as specified in the - /etc/printcap file. - - - - - Nothing happened. - - - If nothing happened, the problem is probably within - FreeBSD and not the hardware. Add the log file - (lf) capability to the entry for the - printer you are debugging in the - /etc/printcap file. For example, here - is the entry for rattan, with the - lf capability: +if [ "$first_two_chars" = "%!" ]; then + # + # It is PostScript; use Ghostscript to scan-convert and print it. + # + # Note that PostScript files are actually interpreted programs, + # and those programs are allowed to write to stdout, which will + # mess up the printed output. So, we redirect stdout to stderr + # and then make descriptor 3 go to stdout, and have Ghostscript + # write its output there. Exercise for the clever reader: + # capture the stderr output from Ghostscript and mail it back to + # the user originating the print job. + # + exec 3>&1 1>&2 + /usr/local/bin/gs -dSAFER -dNOPAUSE -q -sDEVICE=djet500 \ + -sOutputFile=/dev/fd/3 - && exit 0 - + # + /usr/local/bin/gs -dSAFER -dNOPAUSE -q -sDEVICE=djet500 -sOutputFile=- - \ + && exit 0 +else + # + # Plain text or HP/PCL, so just print it directly; print a form + # at the end to eject the last page. + # + echo $first_line && cat && printf "\033&l0H" && +exit 0 +fi + +exit 2 + + Finally, you need to notify LPD of the filter via the + if capability: + + +:if=/usr/local/libexec/hpif: + + That is it. You can type lpr plain.text and + lpr whatever.ps and both should print + successfully. + + + + Conversion Filters + + After completing the simple setup described in Simple Printer Setup, the first + thing you will probably want to do is install conversion filters for + your favorite file formats (besides plain ASCII text). + + + Why Install Conversion Filters? + + Conversion filters make printing various kinds of files easy. + As an example, suppose we do a lot of work with the TeX + typesetting system, and we have a PostScript printer. Every time + we generate a DVI file from TeX, we cannot print it directly until + we convert the DVI file into PostScript. The command sequence + goes like this: + + &prompt.user; dvips seaweed-analysis.dvi +&prompt.user; lpr seaweed-analysis.ps + + By installing a conversion filter for DVI files, we can skip + the hand conversion step each time by having LPD do it for us. + Now, each time we get a DVI file, we are just one step away from + printing it: + + &prompt.user; lpr -d seaweed-analysis.dvi + + We got LPD to do the DVI file conversion for us by specifying + the option. Section Formatting and Conversion + Options lists the conversion options. + + For each of the conversion options you want a printer to + support, install a conversion filter and + specify its pathname in /etc/printcap. A + conversion filter is like the text filter for the simple printer + setup (see section Installing + the Text Filter) except that instead of printing plain + text, the filter converts the file into a format the printer can + understand. + + + + Which Conversions Filters Should I Install? + + You should install the conversion filters you expect to use. + If you print a lot of DVI data, then a DVI conversion filter is in + order. If you have got plenty of troff to print out, then you + probably want a troff filter. + + The following table summarizes the filters that LPD works + with, their capability entries for the + /etc/printcap file, and how to invoke them + with the lpr command: + + + + + + File type + /etc/printcap capability + lpr option + + + + + + cifplot + cf + + + + + DVI + df + + + + + plot + gf + + + + + ditroff + nf + + + + + FORTRAN text + rf + + + + + troff + rf + + + + + raster + vf + + + + + plain text + if + none, , or + + + + + + + In our example, using lpr -d means the + printer needs a df capability in its entry in + /etc/printcap. + + Despite what others might contend, formats like FORTRAN text + and plot are probably obsolete. At your site, you can give new + meanings to these or any of the formatting options just by + installing custom filters. For example, suppose you would like to + directly print Printerleaf files (files from the Interleaf desktop + publishing program), but will never print plot files. You could + install a Printerleaf conversion filter under the + gf capability and then educate your users that + lpr -g mean “print Printerleaf + files.” + + + + Installing Conversion Filters + + Since conversion filters are programs you install outside of + the base FreeBSD installation, they should probably go under + /usr/local. The directory + /usr/local/libexec is a popular location, + since they are specialized programs that only LPD will run; + regular users should not ever need to run them. + + To enable a conversion filter, specify its pathname under the + appropriate capability for the destination printer in + /etc/printcap. + + In our example, we will add the DVI conversion filter to the + entry for the printer named bamboo. Here is + the example /etc/printcap file again, with + the new df capability for the printer + bamboo. + + +# +# /etc/printcap for host rose - added df filter for bamboo +# rattan|line|diablo|lp|Diablo 630 Line Printer:\ :sh:sd=/var/spool/lpd/rattan:\ :lp=/dev/lpt0:\ - :if=/usr/local/libexec/if-simple:\ - :lf=/var/log/rattan.log - - Then, try printing again. Check the log file (in our - example, /var/log/rattan.log) to see - any error messages that might appear. Based on the messages - you see, try to correct the problem. - - If you do not specify a lf - capability, LPD uses /dev/console as a - default. - - - - - - - - - - Using Printers - - This section tells you how to use printers you have setup with - FreeBSD. Here is an overview of the user-level commands: + :if=/usr/local/libexec/if-simple: - - - &man.lpr.1; +bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4:\ + :sh:sd=/var/spool/lpd/bamboo:\ + :lp=/dev/ttyd5:fs#0x82000e1:xs#0x820:rw:\ + :if=/usr/local/libexec/psif:\ + :df=/usr/local/libexec/psdf: - - Print jobs - - - - - &man.lpq.1; + The DVI filter is a shell script named + /usr/local/libexec/psdf. Here is that + script: - - Check printer queues - - - - - &man.lprm.1; + +#!bin/sh +# +# psdf - DVI to PostScript printer filter +# Installed in /usr/local/libexec/psdf +# +# Invoked by lpd when user runs lpr -d +# +exec /usr/local/bin/dvips -f | /usr/local/libexec/lprps "$@" - - Remove jobs from a printer's queue - - - - - There is also an administrative command, &man.lpc.8;, described in - the section Administrating the LPD - Spooler, used to control printers and their queues. + This script runs dvips in filter mode (the + argument) on standard input, which is the job + to print. It then starts the PostScript printer filter + lprps (see section Accommodating Plain + Text Jobs on PostScript Printers) with the arguments LPD + passed to this script. lprps will use those + arguments to account for the pages printed. + + + + More Conversion Filter Examples + + Since there is no fixed set of steps to install conversion + filters, let me instead provide more examples. Use these as + guidance to making your own filters. Use them directly, if + appropriate. + + This example script is a raster (well, GIF file, actually) + conversion filter for a Hewlett Packard LaserJet III-Si + printer: + + +#!/bin/sh +# +# hpvf - Convert GIF files into HP/PCL, then print +# Installed in /usr/local/libexec/hpvf + +PATH=/usr/X11R6/bin:$PATH; export PATH +giftopnm | ppmtopgm | pgmtopbm | pbmtolj -resolution 300 \ + && exit 0 \ + || exit 2 - All three of the commands &man.lpr.1;, &man.lprm.1;, and &man.lpq.1; - accept an option to specify on which - printer/queue to operate, as listed in the - /etc/printcap file. This enables you to submit, - remove, and check on jobs for various printers. If you do not use the - option, then these commands use the printer - specified in the PRINTER environment variable. Finally, - if you do not have a PRINTER environment variable, these - commands default to the printer named lp. + It works by converting the GIF file into a portable anymap, + converting that into a portable graymap, converting that into a + portable bitmap, and converting that into LaserJet/PCL-compatible + data. + + Here is the /etc/printcap file with an + entry for a printer using the above filter: - Hereafter, the terminology default printer - means the printer named in the PRINTER environment - variable, or the printer named lp when there is no - PRINTER environment variable. - - - Printing Jobs - - To print files, type: - - &prompt.user; lpr filename ... - - This prints each of the listed files to the default printer. If - you list no files, &man.lpr.1; reads data to - print from standard input. For example, this command prints some - important system files: + +# +# /etc/printcap for host orchid +# +teak|hp|laserjet|Hewlett Packard LaserJet 3Si:\ + :lp=/dev/lpt0:sh:sd=/var/spool/lpd/teak:mx#0:\ + :if=/usr/local/libexec/hpif:\ + :vf=/usr/local/libexec/hpvf: + + The following script is a conversion filter for troff data + from the groff typesetting system for the PostScript printer named + bamboo: - &prompt.user; lpr /etc/host.conf /etc/hosts.equiv - - To select a specific printer, type: - - &prompt.user; lpr -P printer-name filename ... + +#!/bin/sh +# +# pstf - Convert groff's troff data into PS, then print. +# Installed in /usr/local/libexec/pstf +# +exec grops | /usr/local/libexec/lprps "$@" + + The above script makes use of lprps again + to handle the communication with the printer. If the printer were + on a parallel port, we would use this script instead: - This example prints a long listing of the current directory to the - printer named rattan: - - &prompt.user; ls -l | lpr -P rattan - - Because no files were listed for the - &man.lpr.1; command, lpr read the data to print - from standard input, which was the output of the ls - -l command. - - The &man.lpr.1; command can also accept a wide variety of options - to control formatting, apply file conversions, generate multiple - copies, and so forth. For more information, see the section Printing Options. - - - - Checking Jobs - - When you print with &man.lpr.1;, the data you wish to print is put - together in a package called a “print job”, which is sent - to the LPD spooling system. Each printer has a queue of jobs, and - your job waits in that queue along with other jobs from yourself and - from other users. The printer prints those jobs in a first-come, - first-served order. + +#!/bin/sh +# +# pstf - Convert groff's troff data into PS, then print. +# Installed in /usr/local/libexec/pstf +# +exec grops + + That is it. Here is the entry we need to add to + /etc/printcap to enable the filter: + + +:tf=/usr/local/libexec/pstf: + + Here is an example that might make old hands at FORTRAN blush. + It is a FORTRAN-text filter for any printer that can directly + print plain text. We will install it for the printer + teak: - To display the queue for the default printer, type &man.lpq.1;. - For a specific printer, use the option. For - example, the command + +#!/bin/sh +# +# hprf - FORTRAN text filter for LaserJet 3si: +# Installed in /usr/local/libexec/hprf +# - &prompt.user; lpq -P bamboo +printf "\033&k2G" && fpr && printf "\033&l0H" && + exit 0 +exit 2 + + And we will add this line to the + /etc/printcap for the printer + teak to enable this filter: + + +:rf=/usr/local/libexec/hprf: + + Here is one final, somewhat complex example. We will add a + DVI filter to the LaserJet printer teak + introduced earlier. First, the easy part: updating + /etc/printcap with the location of the DVI + filter: + + +:df=/usr/local/libexec/hpdf: + + Now, for the hard part: making the filter. For that, we need + a DVI-to-LaserJet/PCL conversion program. The FreeBSD ports + collection (see The Ports Collection) + has one: dvi2xx is the name of the package. + Installing this package gives us the program we need, + dvilj2p, which converts DVI into LaserJet IIp, + LaserJet III, and LaserJet 2000 compatible codes. + + dvilj2p makes the filter + hpdf quite complex since + dvilj2p cannot read from standard input. It + wants to work with a filename. What is worse, the filename has to + end in .dvi so using + /dev/fd/0 for standard input is problematic. + We can get around that problem by linking (symbolically) a + temporary file name (one that ends in .dvi) + to /dev/fd/0, thereby forcing + dvilj2p to read from standard input. + + The only other fly in the ointment is the fact that we cannot + use /tmp for the temporary link. Symbolic + links are owned by user and group bin. The + filter runs as user daemon. And the + /tmp directory has the sticky bit set. The + filter can create the link, but it will not be able clean up when + done and remove it since the link will belong to a different + user. + + Instead, the filter will make the symbolic link in the current + working directory, which is the spooling directory (specified by + the sd capability in + /etc/printcap). This is a perfect place for + filters to do their work, especially since there is (sometimes) + more free disk space in the spooling directory than under + /tmp. + + Here, finally, is the filter: + + +#!/bin/sh +# +# hpdf - Print DVI data on HP/PCL printer +# Installed in /usr/local/libexec/hpdf - shows the queue for the printer named bamboo. Here - is an example of the output of the lpq - command: - - bamboo is ready and printing -Rank Owner Job Files Total Size -active kelly 9 /etc/host.conf, /etc/hosts.equiv 88 bytes -2nd kelly 10 (standard input) 1635 bytes -3rd mary 11 ... 78519 bytes - - This shows three jobs in the queue for bamboo. - The first job, submitted by user kelly, got assigned “job - number” 9. Every job for a printer gets a unique job number. - Most of the time you can ignore the job number, but you will need it - if you want to cancel the job; see section Removing Jobs for details. - - Job number nine consists of two files; multiple files given on the - &man.lpr.1; command line are treated as part of a single job. It - is the currently active job (note the word active - under the “Rank” column), which means the printer should - be currently printing that job. The second job consists of data - passed as the standard input to the &man.lpr.1; command. The third - job came from user mary; it is a much larger - job. The pathname of the files she's trying to print is too long to - fit, so the &man.lpq.1; command just shows three dots. +PATH=/usr/local/bin:$PATH; export PATH - The very first line of the output from &man.lpq.1; is also useful: - it tells what the printer is currently doing (or at least what LPD - thinks the printer is doing). +# +# Define a function to clean up our temporary files. These exist +# in the current directory, which will be the spooling directory +# for the printer. +# +cleanup() { + rm -f hpdf$$.dvi +} - The &man.lpq.1; command also support a option - to generate a detailed long listing. Here is an example of - lpq -l: - - waiting for bamboo to become ready (offline ?) -kelly: 1st [job 009rose] - /etc/host.conf 73 bytes - /etc/hosts.equiv 15 bytes +# +# Define a function to handle fatal errors: print the given message +# and exit 2. Exiting with 2 tells LPD to do not try to reprint the +# job. +# +fatal() { + echo "$@" 1>&2 + cleanup + exit 2 +} -kelly: 2nd [job 010rose] - (standard input) 1635 bytes +# +# If user removes the job, LPD will send SIGINT, so trap SIGINT +# (and a few other signals) to clean up after ourselves. +# +trap cleanup 1 2 15 -mary: 3rd [job 011rose] - /home/orchid/mary/research/venus/alpha-regio/mapping 78519 bytes - +# +# Make sure we are not colliding with any existing files. +# +cleanup - - Removing Jobs - - If you change your mind about printing a job, you can remove the - job from the queue with the &man.lprm.1; command. Often, you can - even use &man.lprm.1; to remove an active job, but some or all of the - job might still get printed. - - To remove a job from the default printer, first use - &man.lpq.1; to find the job number. Then type: - - &prompt.user; lprm job-number - - To remove the job from a specific printer, add the - option. The following command removes job number - 10 from the queue for the printer bamboo: - - &prompt.user; lprm -P bamboo 10 - - The &man.lprm.1; command has a few shortcuts: - - - - lprm - +# +# Link the DVI input file to standard input (the file to print). +# +ln -s /dev/fd/0 hpdf$$.dvi || fatal "Cannot symlink /dev/fd/0" - - Removes all jobs (for the default printer) belonging to - you. - - +# +# Make LF = CR+LF +# +printf "\033&k2G" || fatal "Cannot initialize printer" - - lprm user - - - Removes all jobs (for the default printer) belonging to - user. The superuser can remove other - users' jobs; you can remove only your own jobs. - - +# +# Convert and print. Return value from dvilj2p does not seem to be +# reliable, so we ignore it. +# +dvilj2p -M1 -q -e- dfhp$$.dvi - - lprm - - - With no job number, user name, or - appearing on the command line, - &man.lprm.1; removes the currently active job on the - default printer, if it belongs to you. The superuser can remove - any active job. - - - +# +# Clean up and exit +# +cleanup +exit 0 + + + + Automated Conversion: An Alternative To Conversion + Filters + + All these conversion filters accomplish a lot for your + printing environment, but at the cost forcing the user to specify + (on the &man.lpr.1; command line) which one to use. + If your users are not particularly computer literate, having to + specify a filter option will become annoying. What is worse, + though, is that an incorrectly specified filter option may run a + filter on the wrong type of file and cause your printer to spew + out hundreds of sheets of paper. + + Rather than install conversion filters at all, you might want + to try having the text filter (since it is the default filter) + detect the type of file it has been asked to print and then + automatically run the right conversion filter. Tools such as + file can be of help here. Of course, it will + be hard to determine the differences between + some file types—and, of course, you can + still provide conversion filters just for them. + + The FreeBSD ports collection has a text filter that performs + automatic conversion called apsfilter. It can + detect plain text, PostScript, and DVI files, run the proper + conversions, and print. + + - Just use the option with the above shortcuts - to operate on a specific printer instead of the default. For example, - the following command removes all jobs for the current user in the - queue for the printer named rattan: - - &prompt.user; lprm -P rattan - - - - If you are working in a networked environment, &man.lprm.1; will - let you remove jobs only from the - host from which the jobs were submitted, even if the same printer is - available from other hosts. The following command sequence - demonstrates this: - - &prompt.user; lpr -P rattan myfile -&prompt.user; rlogin orchid -&prompt.user; lpq -P rattan -Rank Owner Job Files Total Size -active seeyan 12 ... 49123 bytes -2nd kelly 13 myfile 12 bytes -&prompt.user; lprm -P rattan 13 -rose: Permission denied -&prompt.user; logout -&prompt.user; lprm -P rattan 13 -dfA013rose dequeued -cfA013rose dequeued - - + + Output Filters + + The LPD spooling system supports one other type of filter that + we have not yet explored: an output filter. An output filter is + intended for printing plain text only, like the text filter, but + with many simplifications. If you are using an output filter but no + text filter, then: + + + + LPD starts an output filter once for the entire job instead + of once for each file in the job. + + + + LPD does not make any provision to identify the start or the + end of files within the job for the output filter. + + + + LPD does not pass the user's login or host to the filter, so + it is not intended to do accounting. In fact, it gets only two + arguments: + + + filter-name + -wwidth + -llength + + + Where width is from the + pw capability and + length is from the + pl capability for the printer in + question. + + + + Do not be seduced by an output filter's simplicity. If you + would like each file in a job to start on a different page an output + filter will not work. Use a text filter (also + known as an input filter); see section Installing the Text Filter. + Furthermore, an output filter is actually more + complex in that it has to examine the byte stream being + sent to it for special flag characters and must send signals to + itself on behalf of LPD. + + However, an output filter is necessary if + you want header pages and need to send escape sequences or other + initialization strings to be able to print the header page. (But it + is also futile if you want to charge header + pages to the requesting user's account, since LPD does not give any + user or host information to the output filter.) + + On a single printer, LPD allows both an output filter and text + or other filters. In such cases, LPD will start the output filter + to print the header page (see section Header Pages) + only. LPD then expects the output filter to stop + itself by sending two bytes to the filter: ASCII 031 + followed by ASCII 001. When an output filter sees these two bytes + (031, 001), it should stop by sending SIGSTOP to itself. When LPD's + done running other filters, it will restart the output filter by + sending SIGCONT to it. + + If there is an output filter but no text + filter and LPD is working on a plain text job, LPD uses the output + filter to do the job. As stated before, the output filter will + print each file of the job in sequence with no intervening form + feeds or other paper advancement, and this is probably + not what you want. In almost all cases, you + need a text filter. + + The program lpf, which we introduced earlier + as a text filter, can also run as an output filter. If you need a + quick-and-dirty output filter but do not want to write the byte + detection and signal sending code, try lpf. You + can also wrap lpf in a shell script to handle any + initialization codes the printer might require. + + + + <command>lpf</command>: a Text Filter + + The program /usr/libexec/lpr/lpf that comes + with FreeBSD binary distribution is a text filter (input filter) + that can indent output (job submitted with lpr + -i), allow literal characters to pass (job submitted + with lpr -l), adjust the printing position for + backspaces and tabs in the job, and account for pages printed. It + can also act like an output filter. + + lpf is suitable for many printing + environments. And although it has no capability to send + initialization sequences to a printer, it is easy to write a shell + script to do the needed initialization and then execute + lpf. + + In order for lpf to do page accounting + correctly, it needs correct values filled in for the + pw and pl capabilities in the + /etc/printcap file. It uses these values to + determine how much text can fit on a page and how many pages were in + a user's job. For more information on printer accounting, see Accounting for Printer + Usage. + - - Beyond Plain Text: Printing Options + + Header Pages - The &man.lpr.1; command supports a number of options that control - formatting text, converting graphic and other file formats, producing - multiple copies, handling of the job, and more. This section - describes the options. - - - Formatting and Conversion Options + If you have lots of users, all of them using + various printers, then you probably want to consider header + pages as a necessary evil. + + Header pages, also known as banner or + burst pages identify to whom jobs belong after + they are printed. They are usually printed in large, bold letters, + perhaps with decorative borders, so that in a stack of printouts they + stand out from the real documents that comprise users' jobs. They + enable users to locate their jobs quickly. The obvious drawback to a + header page is that it is yet one more sheet that has to be printed + for every job, their ephemeral usefulness lasting not more than a few + minutes, ultimately finding themselves in a recycling bin or rubbish + heap. (Note that header pages go with each job, not each file in a + job, so the paper waste might not be that bad.) + + The LPD system can provide header pages automatically for your + printouts if your printer can directly print + plain text. If you have a PostScript printer, you will need an + external program to generate the header page; see Header Pages on + PostScript Printers. + + + Enabling Header Pages - The following &man.lpr.1; options control formatting of the - files in the job. Use these options if the job does not contain - plain text or if you want plain text formatted through the - &man.pr.1; utility. - - For example, the following command prints a DVI file (from the - TeX typesetting system) named fish-report.dvi - to the printer named bamboo: - - &prompt.user; lpr -P bamboo -d fish-report.dvi - - These options apply to every file in the job, so you cannot mix - (say) DVI and ditroff files together in a job. Instead, submit the - files as separate jobs, using a different conversion option for each - job. + In the Simple Printer + Setup, we turned off header pages by specifying + sh (meaning “suppress header”) in the + /etc/printcap file. To enable header pages for + a printer, just remove the sh capability. - - All of these options except and - require conversion filters installed for the - destination printer. For example, the option - requires the DVI conversion filter. Section Conversion - Filters gives details. - + Sounds too easy, right? - - - + You are right. You might have to provide + an output filter to send initialization strings to the printer. + Here is an example output filter for Hewlett Packard PCL-compatible + printers: - - Print cifplot files. - - - - - - - - Print DVI files. - - - - - - - - Print FORTRAN text files. - - - - - - - - Print plot data. - - - - - - - - Indent the output by number - columns; if you omit number, indent - by 8 columns. This option works only with certain conversion - filters. - - - Do not put any space between the and - the number. - - - - - - - - - Print literal text data, including control - characters. - - - - - - - - Print ditroff (device independent troff) data. - - - - - -p - - - Format plain text with &man.pr.1; before printing. See - &man.pr.1; for more information. - - - - - - - - Use title on the - &man.pr.1; header instead of the file name. This option has - effect only when used with the - option. - - - - - - - - Print troff data. - - - - - - - - Print raster data. - - - - - Here is an example: this command prints a nicely formatted - version of the &man.ls.1; manual page on the default printer: - - &prompt.user; zcat /usr/share/man/man1/ls.1.gz | troff -t -man | lpr -t - - The &man.zcat.1; command uncompresses the source of the - - &man.ls.1; manual page and passes it to the &man.troff.1; - command, which formats that source and makes GNU troff output and - passes it to &man.lpr.1;, which submits the job to the LPD spooler. - Because we used the option to - - &man.lpr.1;, the spooler will convert the GNU troff output into - a format the default printer can understand when it prints the - job. - - - - Job Handling Options - - The following options to &man.lpr.1; tell LPD to handle the job - specially: - - - - -# copies - - - Produce a number of copies of - each file in the job instead of just one copy. An - administrator may disable this option to reduce printer - wear-and-tear and encourage photocopier usage. See section - Restricting - Multiple Copies. - - This example prints three copies of - parser.c followed by three copies of - parser.h to the default printer: - - &prompt.user; lpr -#3 parser.c parser.h - - - - - -m - - - Send mail after completing the print job. With this - option, the LPD system will send mail to your account when it - finishes handling your job. In its message, it will tell you - if the job completed successfully or if there was an error, - and (often) what the error was. - - - - - -s - - - Do not copy the files to the spooling directory, but make - symbolic links to them instead. - - If you are printing a large job, you probably want to use - this option. It saves space in the spooling directory (your - job might overflow the free space on the filesystem where the - spooling directory resides). It saves time as well since LPD - will not have to copy each and every byte of your job to the - spooling directory. - - There is a drawback, though: since LPD will refer to the - original files directly, you cannot modify or remove them - until they have been printed. - - - If you are printing to a remote printer, LPD will - eventually have to copy files from the local host to the - remote host, so the option will save - space only on the local spooling directory, not the remote. - It is still useful, though. - - - - - - -r - - - Remove the files in the job after copying them to the - spooling directory, or after printing them with the - option. Be careful with this - option! - - - - - - - Header Page Options - - These options to &man.lpr.1; adjust the text that normally - appears on a job's header page. If header pages are suppressed for - the destination printer, these options have no effect. See section - Header Pages - for information about setting up header pages. - - - - -C text - - - Replace the hostname on the header page with - text. The hostname is normally the - name of the host from which the job was submitted. - - - - - -J text - - - Replace the job name on the header page with - text. The job name is normally the - name of the first file of the job, or - stdin if you are printing standard - input. - - - - - -h - - - Do not print any header page. - - - At some sites, this option may have no effect due to the - way header pages are generated. See Header - Pages for details. - - - - - - - - - Administrating Printers - - As an administrator for your printers, you have had to install, - set up, and test them. Using the &man.lpc.8; command, you - can interact with your printers in yet more ways. With &man.lpc.8;, - you can - - - - Start and stop the printers - - - - Enable and disable their queues - - - - Rearrange the order of the jobs in each queue. - - - - First, a note about terminology: if a printer is - stopped, it will not print anything in its queue. - Users can still submit jobs, which will wait in the queue until the - printer is started or the queue is - cleared. - - If a queue is disabled, no user (except root) - can submit jobs for the printer. An enabled - queue allows jobs to be submitted. A printer can be - started for a disabled queue, in which case it - will continue to print jobs in the queue until the queue is - empty. - - In general, you have to have root privileges to use the - &man.lpc.8; command. Ordinary users can use the &man.lpc.8; command - to get printer status and to restart a hung printer only. - - Here is a summary of the &man.lpc.8; commands. Most of the - commands takes a printer-name argument to - tell on which printer to operate. You can use all - for the printer-name to mean all printers - listed in /etc/printcap. - - - - abort - printer-name - - - Cancel the current job and stop the printer. Users can - still submit jobs if the queue's enabled. - - - - - clean - printer-name - - - Remove old files from the printer's spooling directory. - Occasionally, the files that make up a job are not properly - removed by LPD, particularly if there have been errors during - printing or a lot of administrative activity. This command - finds files that do not belong in the spooling directory and - removes them. - - - - - disable - printer-name - - - Disable queuing of new jobs. If the printer's started, it - will continue to print any jobs remaining in the queue. The - superuser (root) can always submit jobs, even to a disabled - queue. - - This command is useful while you are testing a new printer - or filter installation: disable the queue and submit jobs as - root. Other users will not be able to submit jobs until you - complete your testing and re-enable the queue with the - enable command. - - - - - down printer-name - message - - - Take a printer down. Equivalent to - disable followed by stop. - The message appears as the printer's - status whenever a user checks the printer's queue with - &man.lpq.1; or status with lpc - status. - - - - - enable - printer-name - - - Enable the queue for a printer. Users can submit jobs but - the printer will not print anything until it is started. - - - - - help - command-name - - - Print help on the command - command-name. With no - command-name, print a summary of the - commands available. - - - - - restart - printer-name - - - Start the printer. Ordinary users can use this command if - some extraordinary circumstance hangs LPD, but they cannot start - a printer stopped with either the stop or - down commands. The - restart command is equivalent to - abort followed by - start. - - - - - start - printer-name - - - Start the printer. The printer will print jobs in its - queue. - - - - - stop - printer-name - - - Stop the printer. The printer will finish the current job - and will not print anything else in its queue. Even though the - printer is stopped, users can still submit jobs to an enabled - queue. - - - - - topq printer-name - job-or-username - - - Rearrange the queue for - printer-name by placing the jobs with - the listed job numbers or the jobs - belonging to username at the top of - the queue. For this command, you cannot use - all as the - printer-name. - - - - - up - printer-name - - - Bring a printer up; the opposite of the - down command. Equivalent to - start followed by - enable. - - - - - &man.lpc.8; accepts the above commands on the command line. If - you do not enter any commands, &man.lpc.8; enters an interactive mode, - where you can enter commands until you type exit, - quit, or end-of-file. - - - - - Advanced Printer Setup - - This section describes filters for printing specially formatted - files, header pages, printing across networks, and restricting and - accounting for printer usage. - - - Filters - - Although LPD handles network protocols, queuing, access control, - and other aspects of printing, most of the real - work happens in the filters. Filters are - programs that communicate with the printer and handle its device - dependencies and special requirements. In the simple printer setup, - we installed a plain text filter—an extremely simple one that - should work with most printers (section Installing the Text - Filter). - - However, in order to take advantage of format conversion, printer - accounting, specific printer quirks, and so on, you should understand - how filters work. It will ultimately be the filter's responsibility - to handle these aspects. And the bad news is that most of the time - you have to provide filters yourself. The good - news is that many are generally available; when they are not, they are - usually easy to write. - - Also, FreeBSD comes with one, - /usr/libexec/lpr/lpf, that works with many - printers that can print plain text. (It handles backspacing and tabs - in the file, and does accounting, but that is about all it does.) - There are also several filters and filter components in the FreeBSD - ports collection. - - Here is what you will find in this section: - - - - Section How Filters - Work, tries to give an overview of a filter's role in the - printing process. You should read this section to get an - understanding of what is happening “under the hood” - when LPD uses filters. This knowledge could help you anticipate - and debug problems you might encounter as you install more and - more filters on each of your printers. - - - - LPD expects every printer to be able to print plain text by - default. This presents a problem for PostScript (or other - language-based printers) which cannot directly print plain text. - Section Accommodating - Plain Text Jobs on PostScript Printers tells you what you - should do to overcome this problem. I recommend reading this - section if you have a PostScript printer. - - - - PostScript is a popular output format for many programs. Even - some people (myself included) write PostScript code directly. But - PostScript printers are expensive. Section Simulating PostScript on - Non-PostScript Printers tells how you can further modify - a printer's text filter to accept and print PostScript data on a - non-PostScript printer. I recommend reading - this section if you do not have a PostScript printer. - - - - Section Conversion - Filters tells about a way you can automate the conversion - of specific file formats, such as graphic or typesetting data, - into formats your printer can understand. After reading this - section, you should be able to set up your printers such that - users can type lpr -t to print troff data, or - lpr -d to print TeX DVI data, or lpr - -v to print raster image data, and so forth. I - recommend reading this section. - - - - Section Output - Filters tells all about a not often used feature of LPD: - output filters. Unless you are printing header pages (see Header Pages), - you can probably skip that section altogether. - - - - Section lpf: a Text - Filter describes lpf, a fairly - complete if simple text filter for line printers (and laser - printers that act like line printers) that comes with FreeBSD. If - you need a quick way to get printer accounting working for plain - text, or if you have a printer which emits smoke when it sees - backspace characters, you should definitely consider - lpf. - - - - - How Filters Work - - As mentioned before, a filter is an executable program started - by LPD to handle the device-dependent part of communicating with the - printer. - - When LPD wants to print a file in a job, it starts a filter - program. It sets the filter's standard input to the file to print, - its standard output to the printer, and its standard error to the - error logging file (specified in the lf - capability in /etc/printcap, or - /dev/console by default). - - Which filter LPD starts and the filter's arguments depend on - what is listed in the /etc/printcap file and - what arguments the user specified for the job on the - &man.lpr.1; command line. For example, if the user typed - lpr -t, LPD would start the troff filter, listed - in the tf capability for the destination printer. - If the user wanted to print plain text, it would start the - if filter (this is mostly true: see Output Filters for - details). - - There are three kinds of filters you can specify in - /etc/printcap: - - - - The text filter, confusingly called the - input filter in LPD documentation, handles - regular text printing. Think of it as the default filter. LPD - expects every printer to be able to print plain text by default, - and it is the text filter's job to make sure backspaces, tabs, - or other special characters do not confuse the printer. If you - are in an environment where you have to account for printer - usage, the text filter must also account for pages printed, - usually by counting the number of lines printed and comparing - that to the number of lines per page the printer supports. The - text filter is started with the following argument list: - - - filter-name - -c - -wwidth - -llength - -iindent - -n login - -h host - acct-file - - - where - - - - - - - appears if the job's submitted with lpr - -l - - - - - width - - - is the value from the pw (page - width) capability specified in - /etc/printcap, default 132 - - - - - length - - - is the value from the pl (page - length) capability, default 66 - - - - - indent - - - is the amount of the indentation from lpr - -i, default 0 - - - - - login - - - is the account name of the user printing the - file - - - - - host - - - is the host name from which the job was - submitted - - - - - acct-file - - - is the name of the accounting file from the - af capability. - - - - - - - - A conversion filter converts a specific - file format into one the printer can render onto paper. For - example, ditroff typesetting data cannot be directly printed, - but you can install a conversion filter for ditroff files to - convert the ditroff data into a form the printer can digest and - print. Section Conversion - Filters tells all about them. Conversion filters also - need to do accounting, if you need printer accounting. - Conversion filters are started with the following arguments: - - - filter-name - -xpixel-width - -ypixel-height - -n login - -h host - acct-file - - - where pixel-width is the value - from the px capability (default 0) and - pixel-height is the value from the - py capability (default 0). - - - - The output filter is used only if there - is no text filter, or if header pages are enabled. In my - experience, output filters are rarely used. Section Output Filters describe - them. There are only two arguments to an output filter: - - - filter-name - -wwidth - -llength - - - which are identical to the text filters and - arguments. - - - - Filters should also exit with the - following exit status: - - - - exit 0 - - - If the filter printed the file successfully. - - - - - exit 1 - - - If the filter failed to print the file but wants LPD to - try to print the file again. LPD will restart a filter if it - exits with this status. - - - - - exit 2 - - - If the filter failed to print the file and does not want - LPD to try again. LPD will throw out the file. - - - - - The text filter that comes with the FreeBSD release, - /usr/libexec/lpr/lpf, takes advantage of the - page width and length arguments to determine when to send a form - feed and how to account for printer usage. It uses the login, host, - and accounting file arguments to make the accounting entries. - - If you are shopping for filters, see if they are LPD-compatible. - If they are, they must support the argument lists described above. - If you plan on writing filters for general use, then have them - support the same argument lists and exit codes. - - - - Accommodating Plain Text Jobs on PostScript Printers - - If you are the only user of your computer and PostScript (or - other language-based) printer, and you promise to never send plain - text to your printer and to never use features of various programs - that will want to send plain text to your printer, then you do not - need to worry about this section at all. - - But, if you would like to send both PostScript and plain text - jobs to the printer, then you are urged to augment your printer - setup. To do so, we have the text filter detect if the arriving job - is plain text or PostScript. All PostScript jobs must start with - %! (for other printer languages, see your printer - documentation). If those are the first two characters in the job, - we have PostScript, and can pass the rest of the job directly. If - those are not the first two characters in the file, then the filter - will convert the text into PostScript and print the result. - - How do we do this? - - If you have got a serial printer, a great way to do it is to - install lprps. lprps is a - PostScript printer filter which performs two-way communication with - the printer. It updates the printer's status file with verbose - information from the printer, so users and administrators can see - exactly what the state of the printer is (such as toner - low or paper jam). But more - importantly, it includes a program called psif - which detects whether the incoming job is plain text and calls - textps (another program that comes with - lprps) to convert it to PostScript. It then uses - lprps to send the job to the printer. - - lprps is part of the FreeBSD ports collection - (see The Ports Collection). You can - fetch, build and install it yourself, of course. After installing - lprps, just specify the pathname to the - psif program that is part of - lprps. If you installed lprps - from the ports collection, use the following in the serial - PostScript printer's entry in - /etc/printcap: - - -:if=/usr/local/libexec/psif: - - You should also specify the rw capability; - that tells LPD to open the printer in read-write mode. - - If you have a parallel PostScript printer (and therefore cannot - use two-way communication with the printer, which - lprps needs), you can use the following shell - script as the text filter: - - -#!/bin/sh -# -# psif - Print PostScript or plain text on a PostScript printer -# Script version; NOT the version that comes with lprps -# Installed in /usr/local/libexec/psif -# - -read first_line -first_two_chars=`expr "$first_line" : '\(..\)'` - -if [ "$first_two_chars" = "%!" ]; then - # - # PostScript job, print it. - # - echo "$first_line" && cat && printf "\004" && exit 0 - exit 2 -else - # - # Plain text, convert it, then print it. - # - ( echo "$first_line"; cat ) | /usr/local/bin/textps && printf "\004" && exit 0 - exit 2 -fi - - In the above script, textps is a program we - installed separately to convert plain text to PostScript. You can - use any text-to-PostScript program you wish. The FreeBSD ports - collection (see The Ports Collection) - includes a full featured text-to-PostScript program called - a2ps that you might want to investigate. - - - - Simulating PostScript on Non-PostScript Printers - - PostScript is the de facto standard for - high quality typesetting and printing. PostScript is, however, an - expensive standard. Thankfully, Alladin - Enterprises has a free PostScript work-alike called - Ghostscript that runs with FreeBSD. - Ghostscript can read most PostScript files and can render their - pages onto a variety of devices, including many brands of - non-PostScript printers. By installing Ghostscript and using a - special text filter for your printer, you can make your - non-PostScript printer act like a real PostScript printer. - - Ghostscript should be in the FreeBSD ports collection, if you - would like to install it from there. You can fetch, build, and - install it quite easily yourself, as well. - - To simulate PostScript, we have the text filter detect if it is - printing a PostScript file. If it is not, then the filter will pass - the file directly to the printer; otherwise, it will use Ghostscript - to first convert the file into a format the printer will - understand. - - Here is an example: the following script is a text filter - for Hewlett Packard DeskJet 500 printers. For other printers, - substitute the argument to the - gs (Ghostscript) command. (Type gs - -h to get a list of devices the current installation of - Ghostscript supports.) - - -#!/bin/sh -# -# ifhp - Print Ghostscript-simulated PostScript on a DeskJet 500 -# Installed in /usr/local/libexec/hpif - -# -# Treat LF as CR+LF: -# -printf "\033&k2G" || exit 2 - -# -# Read first two characters of the file -# -read first_line -first_two_chars=`expr "$first_line" : '\(..\)'` - -if [ "$first_two_chars" = "%!" ]; then - # - # It is PostScript; use Ghostscript to scan-convert and print it. - # - # Note that PostScript files are actually interpreted programs, - # and those programs are allowed to write to stdout, which will - # mess up the printed output. So, we redirect stdout to stderr - # and then make descriptor 3 go to stdout, and have Ghostscript - # write its output there. Exercise for the clever reader: - # capture the stderr output from Ghostscript and mail it back to - # the user originating the print job. - # - exec 3>&1 1>&2 - /usr/local/bin/gs -dSAFER -dNOPAUSE -q -sDEVICE=djet500 \ - -sOutputFile=/dev/fd/3 - && exit 0 - - # - /usr/local/bin/gs -dSAFER -dNOPAUSE -q -sDEVICE=djet500 -sOutputFile=- - \ - && exit 0 -else - # - # Plain text or HP/PCL, so just print it directly; print a form - # at the end to eject the last page. - # - echo $first_line && cat && printf "\033&l0H" && exit 0 -fi - -exit 2 - - Finally, you need to notify LPD of the filter via the - if capability: - - -:if=/usr/local/libexec/hpif: - - That is it. You can type lpr plain.text and - lpr whatever.ps and both should print - successfully. - - - - Conversion Filters - - After completing the simple setup described in Simple Printer Setup, the first - thing you will probably want to do is install conversion filters for - your favorite file formats (besides plain ASCII text). - - - Why Install Conversion Filters? - - Conversion filters make printing various kinds of files easy. - As an example, suppose we do a lot of work with the TeX - typesetting system, and we have a PostScript printer. Every time - we generate a DVI file from TeX, we cannot print it directly until - we convert the DVI file into PostScript. The command sequence - goes like this: - - &prompt.user; dvips seaweed-analysis.dvi -&prompt.user; lpr seaweed-analysis.ps - - By installing a conversion filter for DVI files, we can skip - the hand conversion step each time by having LPD do it for us. - Now, each time we get a DVI file, we are just one step away from - printing it: - - &prompt.user; lpr -d seaweed-analysis.dvi - - We got LPD to do the DVI file conversion for us by specifying - the option. Section Formatting and Conversion - Options lists the conversion options. - - For each of the conversion options you want a printer to - support, install a conversion filter and - specify its pathname in /etc/printcap. A - conversion filter is like the text filter for the simple printer - setup (see section Installing - the Text Filter) except that instead of printing plain - text, the filter converts the file into a format the printer can - understand. - - - - Which Conversions Filters Should I Install? - - You should install the conversion filters you expect to use. - If you print a lot of DVI data, then a DVI conversion filter is in - order. If you have got plenty of troff to print out, then you - probably want a troff filter. - - The following table summarizes the filters that LPD works - with, their capability entries for the - /etc/printcap file, and how to invoke them - with the lpr command: - - - - - - File type - /etc/printcap capability - lpr option - - - - - - cifplot - cf - - - - - DVI - df - - - - - plot - gf - - - - - ditroff - nf - - - - - FORTRAN text - rf - - - - - troff - rf - - - - - raster - vf - - - - - plain text - if - none, , or - - - - - - - In our example, using lpr -d means the - printer needs a df capability in its entry in - /etc/printcap. - - Despite what others might contend, formats like FORTRAN text - and plot are probably obsolete. At your site, you can give new - meanings to these or any of the formatting options just by - installing custom filters. For example, suppose you would like to - directly print Printerleaf files (files from the Interleaf desktop - publishing program), but will never print plot files. You could - install a Printerleaf conversion filter under the - gf capability and then educate your users that - lpr -g mean “print Printerleaf - files.” - - - - Installing Conversion Filters - - Since conversion filters are programs you install outside of - the base FreeBSD installation, they should probably go under - /usr/local. The directory - /usr/local/libexec is a popular location, - since they are specialized programs that only LPD will run; - regular users should not ever need to run them. - - To enable a conversion filter, specify its pathname under the - appropriate capability for the destination printer in - /etc/printcap. - - In our example, we will add the DVI conversion filter to the - entry for the printer named bamboo. Here is - the example /etc/printcap file again, with - the new df capability for the printer - bamboo. - - -# -# /etc/printcap for host rose - added df filter for bamboo -# -rattan|line|diablo|lp|Diablo 630 Line Printer:\ - :sh:sd=/var/spool/lpd/rattan:\ - :lp=/dev/lpt0:\ - :if=/usr/local/libexec/if-simple: - -bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4:\ - :sh:sd=/var/spool/lpd/bamboo:\ - :lp=/dev/ttyd5:fs#0x82000e1:xs#0x820:rw:\ - :if=/usr/local/libexec/psif:\ - :df=/usr/local/libexec/psdf: - - The DVI filter is a shell script named - /usr/local/libexec/psdf. Here is that - script: - - -#!bin/sh -# -# psdf - DVI to PostScript printer filter -# Installed in /usr/local/libexec/psdf -# -# Invoked by lpd when user runs lpr -d -# -exec /usr/local/bin/dvips -f | /usr/local/libexec/lprps "$@" - - This script runs dvips in filter mode (the - argument) on standard input, which is the job - to print. It then starts the PostScript printer filter - lprps (see section Accommodating Plain - Text Jobs on PostScript Printers) with the arguments LPD - passed to this script. lprps will use those - arguments to account for the pages printed. - - - - More Conversion Filter Examples - - Since there is no fixed set of steps to install conversion - filters, let me instead provide more examples. Use these as - guidance to making your own filters. Use them directly, if - appropriate. - - This example script is a raster (well, GIF file, actually) - conversion filter for a Hewlett Packard LaserJet III-Si - printer: - - -#!/bin/sh -# -# hpvf - Convert GIF files into HP/PCL, then print -# Installed in /usr/local/libexec/hpvf - -PATH=/usr/X11R6/bin:$PATH; export PATH -giftopnm | ppmtopgm | pgmtopbm | pbmtolj -resolution 300 \ - && exit 0 \ - || exit 2 - - It works by converting the GIF file into a portable anymap, - converting that into a portable graymap, converting that into a - portable bitmap, and converting that into LaserJet/PCL-compatible - data. - - Here is the /etc/printcap file with an - entry for a printer using the above filter: - - -# -# /etc/printcap for host orchid -# -teak|hp|laserjet|Hewlett Packard LaserJet 3Si:\ - :lp=/dev/lpt0:sh:sd=/var/spool/lpd/teak:mx#0:\ - :if=/usr/local/libexec/hpif:\ - :vf=/usr/local/libexec/hpvf: - - The following script is a conversion filter for troff data - from the groff typesetting system for the PostScript printer named - bamboo: - - -#!/bin/sh -# -# pstf - Convert groff's troff data into PS, then print. -# Installed in /usr/local/libexec/pstf -# -exec grops | /usr/local/libexec/lprps "$@" - - The above script makes use of lprps again - to handle the communication with the printer. If the printer were - on a parallel port, we would use this script instead: - - -#!/bin/sh -# -# pstf - Convert groff's troff data into PS, then print. -# Installed in /usr/local/libexec/pstf -# -exec grops - - That is it. Here is the entry we need to add to - /etc/printcap to enable the filter: - - -:tf=/usr/local/libexec/pstf: - - Here is an example that might make old hands at FORTRAN blush. - It is a FORTRAN-text filter for any printer that can directly - print plain text. We will install it for the printer - teak: - - -#!/bin/sh -# -# hprf - FORTRAN text filter for LaserJet 3si: -# Installed in /usr/local/libexec/hprf -# - -printf "\033&k2G" && fpr && printf "\033&l0H" && exit 0 -exit 2 - - And we will add this line to the - /etc/printcap for the printer - teak to enable this filter: - - -:rf=/usr/local/libexec/hprf: - - Here is one final, somewhat complex example. We will add a - DVI filter to the LaserJet printer teak - introduced earlier. First, the easy part: updating - /etc/printcap with the location of the DVI - filter: - - -:df=/usr/local/libexec/hpdf: - - Now, for the hard part: making the filter. For that, we need - a DVI-to-LaserJet/PCL conversion program. The FreeBSD ports - collection (see The Ports Collection) - has one: dvi2xx is the name of the package. - Installing this package gives us the program we need, - dvilj2p, which converts DVI into LaserJet IIp, - LaserJet III, and LaserJet 2000 compatible codes. - - dvilj2p makes the filter - hpdf quite complex since - dvilj2p cannot read from standard input. It - wants to work with a filename. What is worse, the filename has to - end in .dvi so using - /dev/fd/0 for standard input is problematic. - We can get around that problem by linking (symbolically) a - temporary file name (one that ends in .dvi) - to /dev/fd/0, thereby forcing - dvilj2p to read from standard input. - - The only other fly in the ointment is the fact that we cannot - use /tmp for the temporary link. Symbolic - links are owned by user and group bin. The - filter runs as user daemon. And the - /tmp directory has the sticky bit set. The - filter can create the link, but it will not be able clean up when - done and remove it since the link will belong to a different - user. - - Instead, the filter will make the symbolic link in the current - working directory, which is the spooling directory (specified by - the sd capability in - /etc/printcap). This is a perfect place for - filters to do their work, especially since there is (sometimes) - more free disk space in the spooling directory than under - /tmp. - - Here, finally, is the filter: - - -#!/bin/sh -# -# hpdf - Print DVI data on HP/PCL printer -# Installed in /usr/local/libexec/hpdf - -PATH=/usr/local/bin:$PATH; export PATH - -# -# Define a function to clean up our temporary files. These exist -# in the current directory, which will be the spooling directory -# for the printer. -# -cleanup() { - rm -f hpdf$$.dvi -} - -# -# Define a function to handle fatal errors: print the given message -# and exit 2. Exiting with 2 tells LPD to do not try to reprint the -# job. -# -fatal() { - echo "$@" 1>&2 - cleanup - exit 2 -} - -# -# If user removes the job, LPD will send SIGINT, so trap SIGINT -# (and a few other signals) to clean up after ourselves. -# -trap cleanup 1 2 15 - -# -# Make sure we are not colliding with any existing files. -# -cleanup - -# -# Link the DVI input file to standard input (the file to print). -# -ln -s /dev/fd/0 hpdf$$.dvi || fatal "Cannot symlink /dev/fd/0" - -# -# Make LF = CR+LF -# -printf "\033&k2G" || fatal "Cannot initialize printer" - -# -# Convert and print. Return value from dvilj2p does not seem to be -# reliable, so we ignore it. -# -dvilj2p -M1 -q -e- dfhp$$.dvi - -# -# Clean up and exit -# -cleanup -exit 0 - - - - Automated Conversion: An Alternative To Conversion - Filters - - All these conversion filters accomplish a lot for your - printing environment, but at the cost forcing the user to specify - (on the &man.lpr.1; command line) which one to use. - If your users are not particularly computer literate, having to - specify a filter option will become annoying. What is worse, - though, is that an incorrectly specified filter option may run a - filter on the wrong type of file and cause your printer to spew - out hundreds of sheets of paper. - - Rather than install conversion filters at all, you might want - to try having the text filter (since it is the default filter) - detect the type of file it has been asked to print and then - automatically run the right conversion filter. Tools such as - file can be of help here. Of course, it will - be hard to determine the differences between - some file types—and, of course, you can - still provide conversion filters just for them. - - The FreeBSD ports collection has a text filter that performs - automatic conversion called apsfilter. It can - detect plain text, PostScript, and DVI files, run the proper - conversions, and print. - - - - - Output Filters - - The LPD spooling system supports one other type of filter that - we have not yet explored: an output filter. An output filter is - intended for printing plain text only, like the text filter, but - with many simplifications. If you are using an output filter but no - text filter, then: - - - - LPD starts an output filter once for the entire job instead - of once for each file in the job. - - - - LPD does not make any provision to identify the start or the - end of files within the job for the output filter. - - - - LPD does not pass the user's login or host to the filter, so - it is not intended to do accounting. In fact, it gets only two - arguments: - - - filter-name - -wwidth - -llength - - - Where width is from the - pw capability and - length is from the - pl capability for the printer in - question. - - - - Do not be seduced by an output filter's simplicity. If you - would like each file in a job to start on a different page an output - filter will not work. Use a text filter (also - known as an input filter); see section Installing the Text Filter. - Furthermore, an output filter is actually more - complex in that it has to examine the byte stream being - sent to it for special flag characters and must send signals to - itself on behalf of LPD. - - However, an output filter is necessary if - you want header pages and need to send escape sequences or other - initialization strings to be able to print the header page. (But it - is also futile if you want to charge header - pages to the requesting user's account, since LPD does not give any - user or host information to the output filter.) - - On a single printer, LPD allows both an output filter and text - or other filters. In such cases, LPD will start the output filter - to print the header page (see section Header Pages) - only. LPD then expects the output filter to stop - itself by sending two bytes to the filter: ASCII 031 - followed by ASCII 001. When an output filter sees these two bytes - (031, 001), it should stop by sending SIGSTOP to itself. When LPD's - done running other filters, it will restart the output filter by - sending SIGCONT to it. - - If there is an output filter but no text - filter and LPD is working on a plain text job, LPD uses the output - filter to do the job. As stated before, the output filter will - print each file of the job in sequence with no intervening form - feeds or other paper advancement, and this is probably - not what you want. In almost all cases, you - need a text filter. - - The program lpf, which we introduced earlier - as a text filter, can also run as an output filter. If you need a - quick-and-dirty output filter but do not want to write the byte - detection and signal sending code, try lpf. You - can also wrap lpf in a shell script to handle any - initialization codes the printer might require. - - - - <command>lpf</command>: a Text Filter - - The program /usr/libexec/lpr/lpf that comes - with FreeBSD binary distribution is a text filter (input filter) - that can indent output (job submitted with lpr - -i), allow literal characters to pass (job submitted - with lpr -l), adjust the printing position for - backspaces and tabs in the job, and account for pages printed. It - can also act like an output filter. - - lpf is suitable for many printing - environments. And although it has no capability to send - initialization sequences to a printer, it is easy to write a shell - script to do the needed initialization and then execute - lpf. - - In order for lpf to do page accounting - correctly, it needs correct values filled in for the - pw and pl capabilities in the - /etc/printcap file. It uses these values to - determine how much text can fit on a page and how many pages were in - a user's job. For more information on printer accounting, see Accounting for Printer - Usage. - - - - - Header Pages - - If you have lots of users, all of them using - various printers, then you probably want to consider header - pages as a necessary evil. - - Header pages, also known as banner or - burst pages identify to whom jobs belong after - they are printed. They are usually printed in large, bold letters, - perhaps with decorative borders, so that in a stack of printouts they - stand out from the real documents that comprise users' jobs. They - enable users to locate their jobs quickly. The obvious drawback to a - header page is that it is yet one more sheet that has to be printed - for every job, their ephemeral usefulness lasting not more than a few - minutes, ultimately finding themselves in a recycling bin or rubbish - heap. (Note that header pages go with each job, not each file in a - job, so the paper waste might not be that bad.) - - The LPD system can provide header pages automatically for your - printouts if your printer can directly print - plain text. If you have a PostScript printer, you will need an - external program to generate the header page; see Header Pages on - PostScript Printers. - - - Enabling Header Pages - - In the Simple Printer - Setup, we turned off header pages by specifying - sh (meaning “suppress header”) in the - /etc/printcap file. To enable header pages for - a printer, just remove the sh capability. - - Sounds too easy, right? - - You are right. You might have to provide - an output filter to send initialization strings to the printer. - Here is an example output filter for Hewlett Packard PCL-compatible - printers: - - + #!/bin/sh # # hpof - Output filter for Hewlett Packard PCL-compatible printers # Installed in /usr/local/libexec/hpof printf "\033&k2G" || exit 2 exec /usr/libexec/lpr/lpf - - Specify the path to the output filter in the - of capability. See Output Filters for more - information. - - Here is an example /etc/printcap file for - the printer teak that we introduced earlier; we - enabled header pages and added the above output filter: - - + + Specify the path to the output filter in the + of capability. See Output Filters for more + information. + + Here is an example /etc/printcap file for + the printer teak that we introduced earlier; we + enabled header pages and added the above output filter: + + # # /etc/printcap for host orchid # teak|hp|laserjet|Hewlett Packard LaserJet 3Si:\ :lp=/dev/lpt0:sd=/var/spool/lpd/teak:mx#0:\ :if=/usr/local/libexec/hpif:\ :vf=/usr/local/libexec/hpvf:\ :of=/usr/local/libexec/hpof: - - Now, when users print jobs to teak, they get - a header page with each job. If users want to spend time searching - for their printouts, they can suppress header pages by submitting - the job with lpr -h; see Header Page Options for - more &man.lpr.1; options. - - - LPD prints a form feed character after the header page. If - your printer uses a different character or sequence of characters - to eject a page, specify them with the ff - capability in /etc/printcap. - + + Now, when users print jobs to teak, they get + a header page with each job. If users want to spend time searching + for their printouts, they can suppress header pages by submitting + the job with lpr -h; see Header Page Options for + more &man.lpr.1; options. + + + LPD prints a form feed character after the header page. If + your printer uses a different character or sequence of characters + to eject a page, specify them with the ff + capability in /etc/printcap. + - Controlling Header Pages - - By enabling header pages, LPD will produce a long - header, a full page of large letters identifying the - user, host, and job. Here is an example (kelly printed the job - named outline from host rose): - - + Controlling Header Pages + + By enabling header pages, LPD will produce a long + header, a full page of large letters identifying the + user, host, and job. Here is an example (kelly printed the job + named outline from host rose): + + k ll ll k l l k l l k k eeee l l y y k k e e l l y y k k eeeeee l l y y kk k e l l y y k k e e l l y yy k k eeee lll lll yyy y y y y yyyy ll t l i t l oooo u u ttttt l ii n nnn eeee o o u u t l i nn n e e o o u u t l i n n eeeeee o o u u t l i n n e o o u uu t t l i n n e e oooo uuu u tt lll iii n n eeee r rrr oooo ssss eeee rr r o o s s e e r o o ss eeeeee r o o ss e r o o s s e e r oooo ssss eeee Job: outline Date: Sun Sep 17 11:04:58 1995 - LPD appends a form feed after this text so the job starts on a - new page (unless you have sf (suppress form - feeds) in the destination printer's entry in - /etc/printcap). - - If you prefer, LPD can make a short header; - specify sb (short banner) in the - /etc/printcap file. The header page will look - like this: - - + LPD appends a form feed after this text so the job starts on a + new page (unless you have sf (suppress form + feeds) in the destination printer's entry in + /etc/printcap). + + If you prefer, LPD can make a short header; + specify sb (short banner) in the + /etc/printcap file. The header page will look + like this: + + rose:kelly Job: outline Date: Sun Sep 17 11:07:51 1995 - Also by default, LPD prints the header page first, then the job. - To reverse that, specify hl (header last) in - /etc/printcap. + Also by default, LPD prints the header page first, then the job. + To reverse that, specify hl (header last) in + /etc/printcap. - Accounting for Header Pages - - Using LPD's built-in header pages enforces a particular paradigm - when it comes to printer accounting: header pages must be - free of charge. - - Why? - - Because the output filter is the only external program that will - have control when the header page is printed that could do - accounting, and it is not provided with any user or - host information or an accounting file, so it has no - idea whom to charge for printer use. It is also not enough to just - “add one page” to the text filter or any of the - conversion filters (which do have user and host information) since - users can suppress header pages with lpr -h. - They could still be charged for header pages they did not print. - Basically, lpr -h will be the preferred option of - environmentally-minded users, but you cannot offer any incentive to - use it. - - It is still not enough to have each of the - filters generate their own header pages (thereby being able to - charge for them). If users wanted the option of suppressing the - header pages with lpr -h, they will still get - them and be charged for them since LPD does not pass any knowledge - of the option to any of the filters. - - So, what are your options? - - You can: - - - - Accept LPD's paradigm and make header pages free. - - - - Install an alternative to LPD, such as LPRng or PLP. Section - Alternatives to the - Standard Spooler tells more about other spooling - software you can substitute for LPD. - - - - Write a smart output filter. Normally, - an output filter is not meant to do anything more than - initialize a printer or do some simple character conversion. It - is suited for header pages and plain text jobs (when there is no - text (input) filter). But, if there is a text filter for the - plain text jobs, then LPD will start the output filter only for - the header pages. And the output filter can parse the header - page text that LPD generates to determine what user and host to - charge for the header page. The only other problem with this - method is that the output filter still does not know what - accounting file to use (it is not passed the name of the file - from the af capability), but if you have a - well-known accounting file, you can hard-code that into the - output filter. To facilitate the parsing step, use the - sh (short header) capability in - /etc/printcap. Then again, all that might - be too much trouble, and users will certainly appreciate the - more generous system administrator who makes header pages - free. - - + Accounting for Header Pages + + Using LPD's built-in header pages enforces a particular paradigm + when it comes to printer accounting: header pages must be + free of charge. + + Why? + + Because the output filter is the only external program that will + have control when the header page is printed that could do + accounting, and it is not provided with any user or + host information or an accounting file, so it has no + idea whom to charge for printer use. It is also not enough to just + “add one page” to the text filter or any of the + conversion filters (which do have user and host information) since + users can suppress header pages with lpr -h. + They could still be charged for header pages they did not print. + Basically, lpr -h will be the preferred option of + environmentally-minded users, but you cannot offer any incentive to + use it. + + It is still not enough to have each of the + filters generate their own header pages (thereby being able to + charge for them). If users wanted the option of suppressing the + header pages with lpr -h, they will still get + them and be charged for them since LPD does not pass any knowledge + of the option to any of the filters. + + So, what are your options? + + You can: + + + + Accept LPD's paradigm and make header pages free. + + + + Install an alternative to LPD, such as LPRng or PLP. Section + Alternatives to the + Standard Spooler tells more about other spooling + software you can substitute for LPD. + + + + Write a smart output filter. Normally, + an output filter is not meant to do anything more than + initialize a printer or do some simple character conversion. It + is suited for header pages and plain text jobs (when there is no + text (input) filter). But, if there is a text filter for the + plain text jobs, then LPD will start the output filter only for + the header pages. And the output filter can parse the header + page text that LPD generates to determine what user and host to + charge for the header page. The only other problem with this + method is that the output filter still does not know what + accounting file to use (it is not passed the name of the file + from the af capability), but if you have a + well-known accounting file, you can hard-code that into the + output filter. To facilitate the parsing step, use the + sh (short header) capability in + /etc/printcap. Then again, all that might + be too much trouble, and users will certainly appreciate the + more generous system administrator who makes header pages + free. + + - Header Pages on PostScript Printers - - As described above, LPD can generate a plain text header page - suitable for many printers. Of course, PostScript cannot directly - print plain text, so the header page feature of LPD is - useless—or mostly so. - - One obvious way to get header pages is to have every conversion - filter and the text filter generate the header page. The filters - should should use the user and host arguments to generate a suitable - header page. The drawback of this method is that users will always - get a header page, even if they submit jobs with lpr - -h. - - Let us explore this method. The following script takes three - arguments (user login name, host name, and job name) and makes a - simple PostScript header page: - - + Header Pages on PostScript Printers + + As described above, LPD can generate a plain text header page + suitable for many printers. Of course, PostScript cannot directly + print plain text, so the header page feature of LPD is + useless—or mostly so. + + One obvious way to get header pages is to have every conversion + filter and the text filter generate the header page. The filters + should should use the user and host arguments to generate a suitable + header page. The drawback of this method is that users will always + get a header page, even if they submit jobs with lpr + -h. + + Let us explore this method. The following script takes three + arguments (user login name, host name, and job name) and makes a + simple PostScript header page: + + #!/bin/sh # # make-ps-header - make a PostScript header page on stdout # Installed in /usr/local/libexec/make-ps-header # # # These are PostScript units (72 to the inch). Modify for A4 or # whatever size paper you are using: # page_width=612 page_height=792 border=72 # # Check arguments # if [ $# -ne 3 ]; then echo "Usage: `basename $0` <user> <host> <job>" 1>&2 exit 1 fi # # Save these, mostly for readability in the PostScript, below. # user=$1 host=$2 job=$3 date=`date` # # Send the PostScript code to stdout. # exec cat <<EOF %!PS % % Make sure we do not interfere with user's job that will follow % save % % Make a thick, unpleasant border around the edge of the paper. % $border $border moveto $page_width $border 2 mul sub 0 rlineto 0 $page_height $border 2 mul sub rlineto currentscreen 3 -1 roll pop 100 3 1 roll setscreen $border 2 mul $page_width sub 0 rlineto closepath 0.8 setgray 10 setlinewidth stroke 0 setgray % % Display user's login name, nice and large and prominent % /Helvetica-Bold findfont 64 scalefont setfont $page_width ($user) stringwidth pop sub 2 div $page_height 200 sub moveto ($user) show % % Now show the boring particulars % /Helvetica findfont 14 scalefont setfont /y 200 def [ (Job:) (Host:) (Date:) ] { 200 y moveto show /y y 18 sub def } forall /Helvetica-Bold findfont 14 scalefont setfont /y 200 def [ ($job) ($host) ($date) ] { 270 y moveto show /y y 18 sub def } forall % % That is it % restore showpage EOF - Now, each of the conversion filters and the text filter can call - this script to first generate the header page, and then print the - user's job. Here is the DVI conversion filter from earlier in this - document, modified to make a header page: + Now, each of the conversion filters and the text filter can call + this script to first generate the header page, and then print the + user's job. Here is the DVI conversion filter from earlier in this + document, modified to make a header page: - + #!/bin/sh # # psdf - DVI to PostScript printer filter # Installed in /usr/local/libexec/psdf # # Invoked by lpd when user runs lpr -d # - + orig_args="$@" fail() { echo "$@" 1>&2 exit 2 } while getopts "x:y:n:h:" option; do case $option in x|y) ;; # Ignore n) login=$OPTARG ;; h) host=$OPTARG ;; *) echo "LPD started `basename $0` wrong." 1>&2 exit 2 ;; esac done [ "$login" ] || fail "No login name" [ "$host" ] || fail "No host name" ( /usr/local/libexec/make-ps-header $login $host "DVI File" /usr/local/bin/dvips -f ) | eval /usr/local/libexec/lprps $orig_args - Notice how the filter has to parse the argument list in order to - determine the user and host name. The parsing for the other - conversion filters is identical. The text filter takes a slightly - different set of arguments, though (see section How Filters - Work). - - As we have mentioned before, the above scheme, though fairly - simple, disables the “suppress header page” option (the - option) to lpr. If users - wanted to save a tree (or a few pennies, if you charge for header - pages), they would not be able to do so, since every filter's going - to print a header page with every job. - - To allow users to shut off header pages on a per-job basis, you - will need to use the trick introduced in section Accounting for - Header Pages: write an output filter that parses the - LPD-generated header page and produces a PostScript version. If the - user submits the job with lpr -h, then LPD will - not generate a header page, and neither will your output filter. - Otherwise, your output filter will read the text from LPD and send - the appropriate header page PostScript code to the printer. - - If you have a PostScript printer on a serial line, you can make - use of lprps, which comes with an output filter, - psof, which does the above. Note that - psof does not charge for header pages. + Notice how the filter has to parse the argument list in order to + determine the user and host name. The parsing for the other + conversion filters is identical. The text filter takes a slightly + different set of arguments, though (see section How Filters + Work). + + As we have mentioned before, the above scheme, though fairly + simple, disables the “suppress header page” option (the + option) to lpr. If users + wanted to save a tree (or a few pennies, if you charge for header + pages), they would not be able to do so, since every filter's going + to print a header page with every job. + + To allow users to shut off header pages on a per-job basis, you + will need to use the trick introduced in section Accounting for + Header Pages: write an output filter that parses the + LPD-generated header page and produces a PostScript version. If the + user submits the job with lpr -h, then LPD will + not generate a header page, and neither will your output filter. + Otherwise, your output filter will read the text from LPD and send + the appropriate header page PostScript code to the printer. + + If you have a PostScript printer on a serial line, you can make + use of lprps, which comes with an output filter, + psof, which does the above. Note that + psof does not charge for header pages. + + + + + Networked Printing + + FreeBSD supports networked printing: sending jobs to remote + printers. Networked printing generally refers to two different + things: + + + + Accessing a printer attached to a remote host. You install a + printer that has a conventional serial or parallel interface on + one host. Then, you set up LPD to enable access to the printer + from other hosts on the network. Section Printers Installed on + Remote Hosts tells how to do this. + + + + Accessing a printer attached directly to a network. The + printer has a network interface in addition (or in place of) a + more conventional serial or parallel interface. Such a printer + might work as follows: + + + + It might understand the LPD protocol and can even queue + jobs from remote hosts. In this case, it acts just like a + regular host running LPD. Follow the same procedure in + section Printers + Installed on Remote Hosts to set up such a + printer. + + + + It might support a data stream network connection. In this + case, you “attach” the printer to one host on the + network by making that host responsible for spooling jobs and + sending them to the printer. Section Printers with + Networked Data Stream Interfaces gives some + suggestions on installing such printers. + + + + + + + Printers Installed on Remote Hosts + + The LPD spooling system has built-in support for sending jobs to + other hosts also running LPD (or are compatible with LPD). This + feature enables you to install a printer on one host and make it + accessible from other hosts. It also works with printers that have + network interfaces that understand the LPD protocol. + + To enable this kind of remote printing, first install a printer + on one host, the printer host, using the simple + printer setup described in Simple + Printer Setup. Do any advanced setup in Advanced Printer Setup that you + need. Make sure to test the printer and see if it works with the + features of LPD you have enabled. Also ensure that the + local host has authorization to use the LPD + service in the remote host (see Restricting Jobs + from Remote Printers). + + If you are using a printer with a network interface that is + compatible with LPD, then the printer host in + the discussion below is the printer itself, and the + printer name is the name you configured for the + printer. See the documentation that accompanied your printer and/or + printer-network interface. + + + If you are using a Hewlett Packard Laserjet then the printer + name text will automatically perform the LF to + CRLF conversion for you, so you will not require the + hpif script. + + + Then, on the other hosts you want to have access to the printer, + make an entry in their /etc/printcap files with + the following: + + + + Name the entry anything you want. For simplicity, though, + you probably want to use the same name and aliases as on the + printer host. + + + + Leave the lp capability blank, explicitly + (:lp=:). + + + + Make a spooling directory and specify its location in the + sd capability. LPD will store jobs here + before they get sent to the printer host. + + + + Place the name of the printer host in the + rm capability. + + + + Place the printer name on the printer + host in the rp + capability. + + + + That is it. You do not need to list conversion filters, page + dimensions, or anything else in the + /etc/printcap file. + + Here is an example. The host rose has two + printers, bamboo and rattan. + We will enable users on the host orchid to print to those printers. + Here is the /etc/printcap file for + orchid (back from section Enabling Header + Pages). It already had the entry for the printer + teak; we have added entries for the two printers + on the host rose: + + +# +# /etc/printcap for host orchid - added (remote) printers on rose +# + +# +# teak is local; it is connected directly to orchid: +# +teak|hp|laserjet|Hewlett Packard LaserJet 3Si:\ + :lp=/dev/lpt0:sd=/var/spool/lpd/teak:mx#0:\ + :if=/usr/local/libexec/ifhp:\ + :vf=/usr/local/libexec/vfhp:\ + :of=/usr/local/libexec/ofhp: + +# +# rattan is connected to rose; send jobs for rattan to rose: +# +rattan|line|diablo|lp|Diablo 630 Line Printer:\ + :lp=:rm=rose:rp=rattan:sd=/var/spool/lpd/rattan: + +# +# bamboo is connected to rose as well: +# +bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4:\ + :lp=:rm=rose:rp=bamboo:sd=/var/spool/lpd/bamboo: + + Then, we just need to make spooling directories on + orchid: + + &prompt.root; mkdir -p /var/spool/lpd/rattan /var/spool/lpd/bamboo +&prompt.root; chmod 770 /var/spool/lpd/rattan /var/spool/lpd/bamboo +&prompt.root; chown daemon.daemon /var/spool/lpd/rattan /var/spool/lpd/bamboo + + Now, users on orchid can print to + rattan and bamboo. If, for + example, a user on orchid typed + + &prompt.user; lpr -P bamboo -d sushi-review.dvi + + the LPD system on orchid would copy the job to the spooling + directory /var/spool/lpd/bamboo and note that + it was a DVI job. As soon as the host rose has room in its + bamboo spooling directory, the two LPDs would + transfer the file to rose. The file would wait in rose's queue + until it was finally printed. It would be converted from DVI to + PostScript (since bamboo is a PostScript printer) on rose. + + + + Printers with Networked Data Stream Interfaces + + Often, when you buy a network interface card for a printer, you + can get two versions: one which emulates a spooler (the more + expensive version), or one which just lets you send data to it as if + you were using a serial or parallel port (the cheaper version). + This section tells how to use the cheaper version. For the more + expensive one, see the previous section Printers Installed on + Remote Hosts. + + The format of the /etc/printcap file lets + you specify what serial or parallel interface to use, and (if you + are using a serial interface), what baud rate, whether to use flow + control, delays for tabs, conversion of newlines, and more. But + there is no way to specify a connection to a printer that is + listening on a TCP/IP or other network port. + + To send data to a networked printer, you need to develop a + communications program that can be called by the text and conversion + filters. Here is one such example: the script + netprint takes all data on standard input and + sends it to a network-attached printer. We specify the hostname of + the printer as the first argument and the port number to which to + connect as the second argument to netprint. Note + that this supports one-way communication only (FreeBSD to printer); + many network printers support two-way communication, and you might + want to take advantage of that (to get printer status, perform + accounting, etc.). + + +#!/usr/bin/perl +# +# netprint - Text filter for printer attached to network +# Installed in /usr/local/libexec/netprint +# +$#ARGV eq 1 || die "Usage: $0 <printer-hostname> <port-number>"; + +$printer_host = $ARGV[0]; +$printer_port = $ARGV[1]; + +require 'sys/socket.ph'; + +($ignore, $ignore, $protocol) = getprotobyname('tcp'); +($ignore, $ignore, $ignore, $ignore, $address) + = gethostbyname($printer_host); + +$sockaddr = pack('S n a4 x8', &AF_INET, $printer_port, $address); + +socket(PRINTER, &PF_INET, &SOCK_STREAM, $protocol) + || die "Can't create TCP/IP stream socket: $!"; +connect(PRINTER, $sockaddr) || die "Can't contact $printer_host: $!"; +while (<STDIN>) { print PRINTER; } +exit 0; + + We can then use this script in various filters. Suppose we had + a Diablo 750-N line printer connected to the network. The printer + accepts data to print on port number 5100. The host name of the + printer is scrivener. Here is the text filter for the + printer: + + +#!/bin/sh +# +# diablo-if-net - Text filter for Diablo printer `scrivener' listening +# on port 5100. Installed in /usr/local/libexec/diablo-if-net +# +exec /usr/libexec/lpr/lpf "$@" | /usr/local/libexec/netprint scrivener 5100 + + + + + Restricting Printer Usage + + This section gives information on restricting printer usage. The + LPD system lets you control who can access a printer, both locally or + remotely, whether they can print multiple copies, how large their jobs + can be, and how large the printer queues can get. + + + Restricting Multiple Copies + + The LPD system makes it easy for users to print multiple copies + of a file. Users can print jobs with lpr -#5 + (for example) and get five copies of each file in the job. Whether + this is a good thing is up to you. + + If you feel multiple copies cause unnecessary wear and tear on + your printers, you can disable the option to + &man.lpr.1; by adding the sc capability to the + /etc/printcap file. When users submit jobs + with the option, they will see: + + lpr: multiple copies are not allowed + + + Note that if you have set up access to a printer remotely (see + section Printers + Installed on Remote Hosts), you need the + sc capability on the remote + /etc/printcap files as well, or else users will + still be able to submit multiple-copy jobs by using another + host. + + Here is an example. This is the + /etc/printcap file for the host + rose. The printer rattan is + quite hearty, so we will allow multiple copies, but the laser + printer bamboo's a bit more delicate, so we will + disable multiple copies by adding the sc + capability: + + +# +# /etc/printcap for host rose - restrict multiple copies on bamboo +# +rattan|line|diablo|lp|Diablo 630 Line Printer:\ + :sh:sd=/var/spool/lpd/rattan:\ + :lp=/dev/lpt0:\ + :if=/usr/local/libexec/if-simple: + +bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4:\ + :sh:sd=/var/spool/lpd/bamboo:sc:\ + :lp=/dev/ttyd5:fs#0x82000e1:xs#0x820:rw:\ + :if=/usr/local/libexec/psif:\ + :df=/usr/local/libexec/psdf: + + Now, we also need to add the sc capability on + the host orchid's + /etc/printcap (and while we are at it, let us + disable multiple copies for the printer + teak): + + +# +# /etc/printcap for host orchid - no multiple copies for local +# printer teak or remote printer bamboo +teak|hp|laserjet|Hewlett Packard LaserJet 3Si:\ + :lp=/dev/lpt0:sd=/var/spool/lpd/teak:mx#0:sc:\ + :if=/usr/local/libexec/ifhp:\ + :vf=/usr/local/libexec/vfhp:\ + :of=/usr/local/libexec/ofhp: + +rattan|line|diablo|lp|Diablo 630 Line Printer:\ + :lp=:rm=rose:rp=rattan:sd=/var/spool/lpd/rattan: + +bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4:\ + :lp=:rm=rose:rp=bamboo:sd=/var/spool/lpd/bamboo:sc: + + By using the sc capability, we prevent the + use of lpr -#, but that still does not prevent + users from running &man.lpr.1; + multiple times, or from submitting the same file multiple times in + one job like this: + + &prompt.user; lpr forsale.sign forsale.sign forsale.sign forsale.sign forsale.sign + + There are many ways to prevent this abuse (including ignoring + it) which you are free to explore. + + + + Restricting Access To Printers + + You can control who can print to what printers by using the UNIX + group mechanism and the rg capability in + /etc/printcap. Just place the users you want + to have access to a printer in a certain group, and then name that + group in the rg capability. + + Users outside the group (including root) will be greeted with + + lpr: Not a member of the restricted group + + if they try to print to the controlled printer. + + As with the sc (suppress multiple copies) + capability, you need to specify rg on remote + hosts that also have access to your printers, if you feel it is + appropriate (see section Printers Installed on + Remote Hosts). + + For example, we will let anyone access the printer + rattan, but only those in group + artists can use bamboo. Here + is the familiar /etc/printcap for host + rose: + + +# +# /etc/printcap for host rose - restricted group for bamboo +# +rattan|line|diablo|lp|Diablo 630 Line Printer:\ + :sh:sd=/var/spool/lpd/rattan:\ + :lp=/dev/lpt0:\ + :if=/usr/local/libexec/if-simple: + +bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4:\ + :sh:sd=/var/spool/lpd/bamboo:sc:rg=artists:\ + :lp=/dev/ttyd5:fs#0x82000e1:xs#0x820:rw:\ + :if=/usr/local/libexec/psif:\ + :df=/usr/local/libexec/psdf: + + Let us leave the other example + /etc/printcap file (for the host + orchid) alone. Of course, anyone on + orchid can print to bamboo. It + might be the case that we only allow certain logins on + orchid anyway, and want them to have access to the + printer. Or not. + + + There can be only one restricted group per printer. + + + + + Controlling Sizes of Jobs Submitted + + If you have many users accessing the printers, you probably need + to put an upper limit on the sizes of the files users can submit to + print. After all, there is only so much free space on the + filesystem that houses the spooling directories, and you also need + to make sure there is room for the jobs of other users. + + LPD enables you to limit the maximum byte size a file in a job + can be with the mx capability. The units are in + BUFSIZ blocks, which are 1024 bytes. If you put a zero for this + capability, there will be no limit on file size; however, if no + mx capability is specified, then a default limit + of 1000 blocks will be used. + + + The limit applies to files in a job, and + not the total job size. + + + LPD will not refuse a file that is larger than the limit you + place on a printer. Instead, it will queue as much of the file up + to the limit, which will then get printed. The rest will be + discarded. Whether this is correct behavior is up for + debate. + + Let us add limits to our example printers + rattan and bamboo. Since + those artists' PostScript files tend to be large, we will limit them + to five megabytes. We will put no limit on the plain text line + printer: + + +# +# /etc/printcap for host rose +# + +# +# No limit on job size: +# +rattan|line|diablo|lp|Diablo 630 Line Printer:\ + :sh:mx#0:sd=/var/spool/lpd/rattan:\ + :lp=/dev/lpt0:\ + :if=/usr/local/libexec/if-simple: + +# +# Limit of five megabytes: +# +bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4:\ + :sh:sd=/var/spool/lpd/bamboo:sc:rg=artists:mx#5000:\ + :lp=/dev/ttyd5:fs#0x82000e1:xs#0x820:rw:\ + :if=/usr/local/libexec/psif:\ + :df=/usr/local/libexec/psdf: + + Again, the limits apply to the local users only. If you have + set up access to your printers remotely, remote users will not get + those limits. You will need to specify the mx + capability in the remote /etc/printcap files as + well. See section Printers Installed on + Remote Hosts for more information on remote + printing. + + There is another specialized way to limit job sizes from remote + printers; see section Restricting Jobs + from Remote Printers. + + + + Restricting Jobs from Remote Printers + + The LPD spooling system provides several ways to restrict print + jobs submitted from remote hosts: + + + + Host restrictions + + + You can control from which remote hosts a local LPD + accepts requests with the files + /etc/hosts.equiv and + /etc/hosts.lpd. LPD checks to see if an + incoming request is from a host listed in either one of these + files. If not, LPD refuses the request. + + The format of these files is simple: one host name per + line. Note that the file + /etc/hosts.equiv is also used by the + &man.ruserok.3; protocol, and affects programs like + &man.rsh.1; and &man.rcp.1;, so be careful. + + For example, here is the + /etc/hosts.lpd file on the host + rose: + + +orchid +violet +madrigal.fishbaum.de + + This means rose will accept requests from + the hosts orchid, violet, + and madrigal.fishbaum.de. If any + other host tries to access rose's LPD, LPD + will refuse them. + + + + + Size restrictions + + + You can control how much free space there needs to remain + on the filesystem where a spooling directory resides. Make a + file called minfree in the spooling + directory for the local printer. Insert in that file a number + representing how many disk blocks (512 bytes) of free space + there has to be for a remote job to be accepted. + + This lets you insure that remote users will not fill your + filesystem. You can also use it to give a certain priority to + local users: they will be able to queue jobs long after the + free disk space has fallen below the amount specified in the + minfree file. + + For example, let us add a minfree + file for the printer bamboo. We examine + /etc/printcap to find the spooling + directory for this printer; here is bamboo's + entry: + + +bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4:\ + :sh:sd=/var/spool/lpd/bamboo:sc:rg=artists:mx#5000:\ + :lp=/dev/ttyd5:fs#0x82000e1:xs#0x820:rw:mx#5000:\ + :if=/usr/local/libexec/psif:\ + :df=/usr/local/libexec/psdf: + + The spooling directory is the given in the + sd capability. We will make three + megabytes (which is 6144 disk blocks) the amount of free disk + space that must exist on the filesystem for LPD to accept + remote jobs: + + &prompt.root; echo 6144 > /var/spool/lpd/bam +boo/minfree + + + + + User restrictions + + + You can control which remote users can print to local + printers by specifying the rs capability in + /etc/printcap. When + rs appears in the entry for a + locally-attached printer, LPD will accept jobs from remote + hosts if the user submitting the job also + has an account of the same login name on the local host. + Otherwise, LPD refuses the job. + + This capability is particularly useful in an environment + where there are (for example) different departments sharing a + network, and some users transcend departmental boundaries. By + giving them accounts on your systems, they can use your + printers from their own departmental systems. If you would + rather allow them to use only your + printers and not your compute resources, you can give them + “token” accounts, with no home directory and a + useless shell like /usr/bin/false. + + + + + + + + Accounting for Printer Usage + + So, you need to charge for printouts. And why not? Paper and ink + cost money. And then there are maintenance costs—printers are + loaded with moving parts and tend to break down. You have examined + your printers, usage patterns, and maintenance fees and have come up + with a per-page (or per-foot, per-meter, or per-whatever) cost. Now, + how do you actually start accounting for printouts? + + Well, the bad news is the LPD spooling system does not provide + much help in this department. Accounting is highly dependent on the + kind of printer in use, the formats being printed, and + your requirements in charging for printer + usage. + + To implement accounting, you have to modify a printer's text + filter (to charge for plain text jobs) and the conversion filters (to + charge for other file formats), to count pages or query the printer + for pages printed. You cannot get away with using the simple output + filter, since it cannot do accounting. See section Filters. + + Generally, there are two ways to do accounting: + + + + Periodic accounting is the more common + way, possibly because it is easier. Whenever someone prints a + job, the filter logs the user, host, and number of pages to an + accounting file. Every month, semester, year, or whatever time + period you prefer, you collect the accounting files for the + various printers, tally up the pages printed by users, and charge + for usage. Then you truncate all the logging files, starting with + a clean slate for the next period. + + + + Timely accounting is less common, + probably because it is more difficult. This method has the + filters charge users for printouts as soon as they use the + printers. Like disk quotas, the accounting is immediate. You can + prevent users from printing when their account goes in the red, + and might provide a way for users to check and adjust their + “print quotas.” But this method requires some database + code to track users and their quotas. + + + + The LPD spooling system supports both methods easily: since you + have to provide the filters (well, most of the time), you also have to + provide the accounting code. But there is a bright side: you have + enormous flexibility in your accounting methods. For example, you + choose whether to use periodic or timely accounting. You choose what + information to log: user names, host names, job types, pages printed, + square footage of paper used, how long the job took to print, and so + forth. And you do so by modifying the filters to save this + information. + + + Quick and Dirty Printer Accounting + + FreeBSD comes with two programs that can get you set up with + simple periodic accounting right away. They are the text filter + lpf, described in section lpf: a Text Filter, and + &man.pac.8;, a program to gather and total + entries from printer accounting files. + + As mentioned in the section on filters (Filters), LPD starts + the text and the conversion filters with the name of the accounting + file to use on the filter command line. The filters can use this + argument to know where to write an accounting file entry. The name + of this file comes from the af capability in + /etc/printcap, and if not specified as an + absolute path, is relative to the spooling directory. + + LPD starts lpf with page width and length + arguments (from the pw and pl + capabilities). lpf uses these arguments to + determine how much paper will be used. After sending the file to + the printer, it then writes an accounting entry in the accounting + file. The entries look like this: + + +2.00 rose:andy +3.00 rose:kelly +3.00 orchid:mary +5.00 orchid:mary +2.00 orchid:zhang + + You should use a separate accounting file for each printer, as + lpf has no file locking logic built into it, and + two lpfs might corrupt each other's entries if + they were to write to the same file at the same time. A easy way to + insure a separate accounting file for each printer is to use + af=acct in /etc/printcap. + Then, each accounting file will be in the spooling directory for a + printer, in a file named acct. + + When you are ready to charge users for printouts, run the + &man.pac.8; program. Just change to the spooling directory for + the printer you want to collect on and type pac. + You will get a dollar-centric summary like the following: + + Login pages/feet runs price +orchid:kelly 5.00 1 $ 0.10 +orchid:mary 31.00 3 $ 0.62 +orchid:zhang 9.00 1 $ 0.18 +rose:andy 2.00 1 $ 0.04 +rose:kelly 177.00 104 $ 3.54 +rose:mary 87.00 32 $ 1.74 +rose:root 26.00 12 $ 0.52 + +total 337.00 154 $ 6.74 + + These are the arguments &man.pac.8; expects: + + + + + + + Which printer to summarize. + This option works only if there is an absolute path in the + af capability in + /etc/printcap. + + + + + + + + Sort the output by cost instead of alphabetically by user + name. + + + + + + + + Ignore host name in the accounting files. With this + option, user smith on host + alpha is the same user + smith on host gamma. + Without, they are different users. + + + + + + + + Compute charges with price + dollars per page or per foot instead of the price from the + pc capability in + /etc/printcap, or two cents (the + default). You can specify price as + a floating point number. + + + + + + + + Reverse the sort order. + + + + + + + + Make an accounting summary file and truncate the + accounting file. + + + + + name + … + + + Print accounting information for the given user + names only. + + + + + In the default summary that &man.pac.8; produces, you see the + number of pages printed by each user from various hosts. If, at + your site, host does not matter (because users can use any host), + run pac -m, to produce the following + summary: + + Login pages/feet runs price +andy 2.00 1 $ 0.04 +kelly 182.00 105 $ 3.64 +mary 118.00 35 $ 2.36 +root 26.00 12 $ 0.52 +zhang 9.00 1 $ 0.18 + +total 337.00 154 $ 6.74 + + + To compute the dollar amount due, + &man.pac.8; uses the pc capability in the + /etc/printcap file (default of 200, or 2 cents + per page). Specify, in hundredths of cents, the price per page or + per foot you want to charge for printouts in this capability. You + can override this value when you run &man.pac.8; with the + option. The units for the + option are in dollars, though, not hundredths of cents. For + example, + + &prompt.root; pac -p1.50 + + makes each page cost one dollar and fifty cents. You can really + rake in the profits by using this option. + + Finally, running pac -s will save the summary + information in a summary accounting file, which is named the same as + the printer's accounting file, but with _sum + appended to the name. It then truncates the accounting file. When + you run &man.pac.8; again, it rereads the + summary file to get starting totals, then adds information from the + regular accounting file. + + + + How Can You Count Pages Printed? + + In order to perform even remotely accurate accounting, you need + to be able to determine how much paper a job uses. This is the + essential problem of printer accounting. + + For plain text jobs, the problem's not that hard to solve: you + count how many lines are in a job and compare it to how many lines + per page your printer supports. Do not forget to take into account + backspaces in the file which overprint lines, or long logical lines + that wrap onto one or more additional physical lines. + + The text filter lpf (introduced in lpf: a Text Filter) takes + into account these things when it does accounting. If you are + writing a text filter which needs to do accounting, you might want + to examine lpf's source code. + + How do you handle other file formats, though? + + Well, for DVI-to-LaserJet or DVI-to-PostScript conversion, you + can have your filter parse the diagnostic output of + dvilj or dvips and look to see + how many pages were converted. You might be able to do similar + things with other file formats and conversion programs. + + But these methods suffer from the fact that the printer may not + actually print all those pages. For example, it could jam, run out + of toner, or explode—and the user would still get + charged. + + So, what can you do? + + There is only one sure way to do + accurate accounting. Get a printer that can + tell you how much paper it uses, and attach it via a serial line or + a network connection. Nearly all PostScript printers support this + notion. Other makes and models do as well (networked Imagen laser + printers, for example). Modify the filters for these printers to + get the page usage after they print each job and have them log + accounting information based on that value + only. There is no line counting nor + error-prone file examination required. + + Of course, you can always be generous and make all printouts + free. + + + + Using Printers - - Networked Printing - - FreeBSD supports networked printing: sending jobs to remote - printers. Networked printing generally refers to two different - things: + This section tells you how to use printers you have setup with + FreeBSD. Here is an overview of the user-level commands: + + + + &man.lpr.1; + + + Print jobs + + - + + &man.lpq.1; + - Accessing a printer attached to a remote host. You install a - printer that has a conventional serial or parallel interface on - one host. Then, you set up LPD to enable access to the printer - from other hosts on the network. Section Printers Installed on - Remote Hosts tells how to do this. + Check printer queues + + + + &man.lprm.1; - Accessing a printer attached directly to a network. The - printer has a network interface in addition (or in place of) a - more conventional serial or parallel interface. Such a printer - might work as follows: - - - - It might understand the LPD protocol and can even queue - jobs from remote hosts. In this case, it acts just like a - regular host running LPD. Follow the same procedure in - section Printers - Installed on Remote Hosts to set up such a - printer. - - - - It might support a data stream network connection. In this - case, you “attach” the printer to one host on the - network by making that host responsible for spooling jobs and - sending them to the printer. Section Printers with - Networked Data Stream Interfaces gives some - suggestions on installing such printers. - - + Remove jobs from a printer's queue - - - - Printers Installed on Remote Hosts + + + + There is also an administrative command, &man.lpc.8;, described in + the section Administrating the LPD + Spooler, used to control printers and their queues. - The LPD spooling system has built-in support for sending jobs to - other hosts also running LPD (or are compatible with LPD). This - feature enables you to install a printer on one host and make it - accessible from other hosts. It also works with printers that have - network interfaces that understand the LPD protocol. - - To enable this kind of remote printing, first install a printer - on one host, the printer host, using the simple - printer setup described in Simple - Printer Setup. Do any advanced setup in Advanced Printer Setup that you - need. Make sure to test the printer and see if it works with the - features of LPD you have enabled. Also ensure that the - local host has authorization to use the LPD - service in the remote host (see Restricting Jobs - from Remote Printers). - - If you are using a printer with a network interface that is - compatible with LPD, then the printer host in - the discussion below is the printer itself, and the - printer name is the name you configured for the - printer. See the documentation that accompanied your printer and/or - printer-network interface. - - - If you are using a Hewlett Packard Laserjet then the printer - name text will automatically perform the LF to - CRLF conversion for you, so you will not require the - hpif script. - + All three of the commands &man.lpr.1;, &man.lprm.1;, and &man.lpq.1; + accept an option to specify on which + printer/queue to operate, as listed in the + /etc/printcap file. This enables you to submit, + remove, and check on jobs for various printers. If you do not use the + option, then these commands use the printer + specified in the PRINTER environment variable. Finally, + if you do not have a PRINTER environment variable, these + commands default to the printer named lp. + + Hereafter, the terminology default printer + means the printer named in the PRINTER environment + variable, or the printer named lp when there is no + PRINTER environment variable. + + + Printing Jobs + + To print files, type: + + &prompt.user; lpr filename ... - Then, on the other hosts you want to have access to the printer, - make an entry in their /etc/printcap files with - the following: + This prints each of the listed files to the default printer. If + you list no files, &man.lpr.1; reads data to + print from standard input. For example, this command prints some + important system files: - - - Name the entry anything you want. For simplicity, though, - you probably want to use the same name and aliases as on the - printer host. - - - - Leave the lp capability blank, explicitly - (:lp=:). - - - - Make a spooling directory and specify its location in the - sd capability. LPD will store jobs here - before they get sent to the printer host. - - - - Place the name of the printer host in the - rm capability. - - - - Place the printer name on the printer - host in the rp - capability. - - - - That is it. You do not need to list conversion filters, page - dimensions, or anything else in the - /etc/printcap file. - - Here is an example. The host rose has two - printers, bamboo and rattan. - We will enable users on the host orchid to print to those printers. - Here is the /etc/printcap file for - orchid (back from section Enabling Header - Pages). It already had the entry for the printer - teak; we have added entries for the two printers - on the host rose: - - -# -# /etc/printcap for host orchid - added (remote) printers on rose -# + &prompt.user; lpr /etc/host.conf /etc/hosts.equiv + + To select a specific printer, type: + + &prompt.user; lpr -P printer-name filename ... -# -# teak is local; it is connected directly to orchid: -# -teak|hp|laserjet|Hewlett Packard LaserJet 3Si:\ - :lp=/dev/lpt0:sd=/var/spool/lpd/teak:mx#0:\ - :if=/usr/local/libexec/ifhp:\ - :vf=/usr/local/libexec/vfhp:\ - :of=/usr/local/libexec/ofhp: + This example prints a long listing of the current directory to the + printer named rattan: + + &prompt.user; ls -l | lpr -P rattan + + Because no files were listed for the + &man.lpr.1; command, lpr read the data to print + from standard input, which was the output of the ls + -l command. + + The &man.lpr.1; command can also accept a wide variety of options + to control formatting, apply file conversions, generate multiple + copies, and so forth. For more information, see the section Printing Options. + + + + Checking Jobs + + When you print with &man.lpr.1;, the data you wish to print is put + together in a package called a “print job”, which is sent + to the LPD spooling system. Each printer has a queue of jobs, and + your job waits in that queue along with other jobs from yourself and + from other users. The printer prints those jobs in a first-come, + first-served order. -# -# rattan is connected to rose; send jobs for rattan to rose: -# -rattan|line|diablo|lp|Diablo 630 Line Printer:\ - :lp=:rm=rose:rp=rattan:sd=/var/spool/lpd/rattan: + To display the queue for the default printer, type &man.lpq.1;. + For a specific printer, use the option. For + example, the command -# -# bamboo is connected to rose as well: -# -bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4:\ - :lp=:rm=rose:rp=bamboo:sd=/var/spool/lpd/bamboo: + &prompt.user; lpq -P bamboo - Then, we just need to make spooling directories on - orchid: - - &prompt.root; mkdir -p /var/spool/lpd/rattan /var/spool/lpd/bamboo -&prompt.root; chmod 770 /var/spool/lpd/rattan /var/spool/lpd/bamboo -&prompt.root; chown daemon.daemon /var/spool/lpd/rattan /var/spool/lpd/bamboo - - Now, users on orchid can print to - rattan and bamboo. If, for - example, a user on orchid typed - - &prompt.user; lpr -P bamboo -d sushi-review.dvi - - the LPD system on orchid would copy the job to the spooling - directory /var/spool/lpd/bamboo and note that - it was a DVI job. As soon as the host rose has room in its - bamboo spooling directory, the two LPDs would - transfer the file to rose. The file would wait in rose's queue - until it was finally printed. It would be converted from DVI to - PostScript (since bamboo is a PostScript printer) on rose. - - - - Printers with Networked Data Stream Interfaces - - Often, when you buy a network interface card for a printer, you - can get two versions: one which emulates a spooler (the more - expensive version), or one which just lets you send data to it as if - you were using a serial or parallel port (the cheaper version). - This section tells how to use the cheaper version. For the more - expensive one, see the previous section Printers Installed on - Remote Hosts. + shows the queue for the printer named bamboo. Here + is an example of the output of the lpq + command: - The format of the /etc/printcap file lets - you specify what serial or parallel interface to use, and (if you - are using a serial interface), what baud rate, whether to use flow - control, delays for tabs, conversion of newlines, and more. But - there is no way to specify a connection to a printer that is - listening on a TCP/IP or other network port. + bamboo is ready and printing +Rank Owner Job Files Total Size +active kelly 9 /etc/host.conf, /etc/hosts.equiv 88 bytes +2nd kelly 10 (standard input) 1635 bytes +3rd mary 11 ... 78519 bytes - To send data to a networked printer, you need to develop a - communications program that can be called by the text and conversion - filters. Here is one such example: the script - netprint takes all data on standard input and - sends it to a network-attached printer. We specify the hostname of - the printer as the first argument and the port number to which to - connect as the second argument to netprint. Note - that this supports one-way communication only (FreeBSD to printer); - many network printers support two-way communication, and you might - want to take advantage of that (to get printer status, perform - accounting, etc.). - - -#!/usr/bin/perl -# -# netprint - Text filter for printer attached to network -# Installed in /usr/local/libexec/netprint -# -$#ARGV eq 1 || die "Usage: $0 <printer-hostname> <port-number>"; + This shows three jobs in the queue for bamboo. + The first job, submitted by user kelly, got assigned “job + number” 9. Every job for a printer gets a unique job number. + Most of the time you can ignore the job number, but you will need it + if you want to cancel the job; see section Removing Jobs for details. + + Job number nine consists of two files; multiple files given on the + &man.lpr.1; command line are treated as part of a single job. It + is the currently active job (note the word active + under the “Rank” column), which means the printer should + be currently printing that job. The second job consists of data + passed as the standard input to the &man.lpr.1; command. The third + job came from user mary; it is a much larger + job. The pathname of the files she's trying to print is too long to + fit, so the &man.lpq.1; command just shows three dots. -$printer_host = $ARGV[0]; -$printer_port = $ARGV[1]; + The very first line of the output from &man.lpq.1; is also useful: + it tells what the printer is currently doing (or at least what LPD + thinks the printer is doing). -require 'sys/socket.ph'; + The &man.lpq.1; command also support a option + to generate a detailed long listing. Here is an example of + lpq -l: + + waiting for bamboo to become ready (offline ?) +kelly: 1st [job 009rose] + /etc/host.conf 73 bytes + /etc/hosts.equiv 15 bytes -($ignore, $ignore, $protocol) = getprotobyname('tcp'); -($ignore, $ignore, $ignore, $ignore, $address) - = gethostbyname($printer_host); +kelly: 2nd [job 010rose] + (standard input) 1635 bytes -$sockaddr = pack('S n a4 x8', &AF_INET, $printer_port, $address); +mary: 3rd [job 011rose] + /home/orchid/mary/research/venus/alpha-regio/mapping 78519 bytes + -socket(PRINTER, &PF_INET, &SOCK_STREAM, $protocol) - || die "Can't create TCP/IP stream socket: $!"; -connect(PRINTER, $sockaddr) || die "Can't contact $printer_host: $!"; -while (<STDIN>) { print PRINTER; } -exit 0; + + Removing Jobs + + If you change your mind about printing a job, you can remove the + job from the queue with the &man.lprm.1; command. Often, you can + even use &man.lprm.1; to remove an active job, but some or all of the + job might still get printed. + + To remove a job from the default printer, first use + &man.lpq.1; to find the job number. Then type: + + &prompt.user; lprm job-number - We can then use this script in various filters. Suppose we had - a Diablo 750-N line printer connected to the network. The printer - accepts data to print on port number 5100. The host name of the - printer is scrivener. Here is the text filter for the - printer: + To remove the job from a specific printer, add the + option. The following command removes job number + 10 from the queue for the printer bamboo: + + &prompt.user; lprm -P bamboo 10 + + The &man.lprm.1; command has a few shortcuts: + + + + lprm - - -#!/bin/sh -# -# diablo-if-net - Text filter for Diablo printer `scrivener' listening -# on port 5100. Installed in /usr/local/libexec/diablo-if-net -# -exec /usr/libexec/lpr/lpf "$@" | /usr/local/libexec/netprint scrivener 5100 - + + Removes all jobs (for the default printer) belonging to + you. + + + + + lprm user + + + Removes all jobs (for the default printer) belonging to + user. The superuser can remove other + users' jobs; you can remove only your own jobs. + + + + + lprm + + + With no job number, user name, or + appearing on the command line, + &man.lprm.1; removes the currently active job on the + default printer, if it belongs to you. The superuser can remove + any active job. + + + + + Just use the option with the above shortcuts + to operate on a specific printer instead of the default. For example, + the following command removes all jobs for the current user in the + queue for the printer named rattan: + + &prompt.user; lprm -P rattan - + + + If you are working in a networked environment, &man.lprm.1; will + let you remove jobs only from the + host from which the jobs were submitted, even if the same printer is + available from other hosts. The following command sequence + demonstrates this: + + &prompt.user; lpr -P rattan myfile +&prompt.user; rlogin orchid +&prompt.user; lpq -P rattan +Rank Owner Job Files Total Size +active seeyan 12 ... 49123 bytes +2nd kelly 13 myfile 12 bytes +&prompt.user; lprm -P rattan 13 +rose: Permission denied +&prompt.user; logout +&prompt.user; lprm -P rattan 13 +dfA013rose dequeued +cfA013rose dequeued + + - - Restricting Printer Usage - - This section gives information on restricting printer usage. The - LPD system lets you control who can access a printer, both locally or - remotely, whether they can print multiple copies, how large their jobs - can be, and how large the printer queues can get. + + Beyond Plain Text: Printing Options - - Restricting Multiple Copies + The &man.lpr.1; command supports a number of options that control + formatting text, converting graphic and other file formats, producing + multiple copies, handling of the job, and more. This section + describes the options. + + + Formatting and Conversion Options - The LPD system makes it easy for users to print multiple copies - of a file. Users can print jobs with lpr -#5 - (for example) and get five copies of each file in the job. Whether - this is a good thing is up to you. + The following &man.lpr.1; options control formatting of the + files in the job. Use these options if the job does not contain + plain text or if you want plain text formatted through the + &man.pr.1; utility. - If you feel multiple copies cause unnecessary wear and tear on - your printers, you can disable the option to - &man.lpr.1; by adding the sc capability to the - /etc/printcap file. When users submit jobs - with the option, they will see: + For example, the following command prints a DVI file (from the + TeX typesetting system) named fish-report.dvi + to the printer named bamboo: - lpr: multiple copies are not allowed - - - Note that if you have set up access to a printer remotely (see - section Printers - Installed on Remote Hosts), you need the - sc capability on the remote - /etc/printcap files as well, or else users will - still be able to submit multiple-copy jobs by using another - host. - - Here is an example. This is the - /etc/printcap file for the host - rose. The printer rattan is - quite hearty, so we will allow multiple copies, but the laser - printer bamboo's a bit more delicate, so we will - disable multiple copies by adding the sc - capability: - - -# -# /etc/printcap for host rose - restrict multiple copies on bamboo -# -rattan|line|diablo|lp|Diablo 630 Line Printer:\ - :sh:sd=/var/spool/lpd/rattan:\ - :lp=/dev/lpt0:\ - :if=/usr/local/libexec/if-simple: - -bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4:\ - :sh:sd=/var/spool/lpd/bamboo:sc:\ - :lp=/dev/ttyd5:fs#0x82000e1:xs#0x820:rw:\ - :if=/usr/local/libexec/psif:\ - :df=/usr/local/libexec/psdf: - - Now, we also need to add the sc capability on - the host orchid's - /etc/printcap (and while we are at it, let us - disable multiple copies for the printer - teak): + &prompt.user; lpr -P bamboo -d fish-report.dvi + + These options apply to every file in the job, so you cannot mix + (say) DVI and ditroff files together in a job. Instead, submit the + files as separate jobs, using a different conversion option for each + job. - -# -# /etc/printcap for host orchid - no multiple copies for local -# printer teak or remote printer bamboo -teak|hp|laserjet|Hewlett Packard LaserJet 3Si:\ - :lp=/dev/lpt0:sd=/var/spool/lpd/teak:mx#0:sc:\ - :if=/usr/local/libexec/ifhp:\ - :vf=/usr/local/libexec/vfhp:\ - :of=/usr/local/libexec/ofhp: + + All of these options except and + require conversion filters installed for the + destination printer. For example, the option + requires the DVI conversion filter. Section Conversion + Filters gives details. + -rattan|line|diablo|lp|Diablo 630 Line Printer:\ - :lp=:rm=rose:rp=rattan:sd=/var/spool/lpd/rattan: + + + -bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4:\ - :lp=:rm=rose:rp=bamboo:sd=/var/spool/lpd/bamboo:sc: + + Print cifplot files. + + + + + - By using the sc capability, we prevent the - use of lpr -#, but that still does not prevent - users from running &man.lpr.1; - multiple times, or from submitting the same file multiple times in - one job like this: - - &prompt.user; lpr forsale.sign forsale.sign forsale.sign forsale.sign forsale.sign - - There are many ways to prevent this abuse (including ignoring - it) which you are free to explore. - - - - Restricting Access To Printers + + Print DVI files. + + + + + + + + Print FORTRAN text files. + + + + + + + + Print plot data. + + + + + + + + Indent the output by number + columns; if you omit number, indent + by 8 columns. This option works only with certain conversion + filters. - You can control who can print to what printers by using the UNIX - group mechanism and the rg capability in - /etc/printcap. Just place the users you want - to have access to a printer in a certain group, and then name that - group in the rg capability. + + Do not put any space between the and + the number. + + + + + + - Users outside the group (including root) will be greeted with + + Print literal text data, including control + characters. + + - lpr: Not a member of the restricted group + + + + + Print ditroff (device independent troff) data. + + - if they try to print to the controlled printer. - - As with the sc (suppress multiple copies) - capability, you need to specify rg on remote - hosts that also have access to your printers, if you feel it is - appropriate (see section Printers Installed on - Remote Hosts). + + -p - For example, we will let anyone access the printer - rattan, but only those in group - artists can use bamboo. Here - is the familiar /etc/printcap for host - rose: - - -# -# /etc/printcap for host rose - restricted group for bamboo -# -rattan|line|diablo|lp|Diablo 630 Line Printer:\ - :sh:sd=/var/spool/lpd/rattan:\ - :lp=/dev/lpt0:\ - :if=/usr/local/libexec/if-simple: - -bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4:\ - :sh:sd=/var/spool/lpd/bamboo:sc:rg=artists:\ - :lp=/dev/ttyd5:fs#0x82000e1:xs#0x820:rw:\ - :if=/usr/local/libexec/psif:\ - :df=/usr/local/libexec/psdf: - - Let us leave the other example - /etc/printcap file (for the host - orchid) alone. Of course, anyone on - orchid can print to bamboo. It - might be the case that we only allow certain logins on - orchid anyway, and want them to have access to the - printer. Or not. - - - There can be only one restricted group per printer. - - - - - Controlling Sizes of Jobs Submitted - - If you have many users accessing the printers, you probably need - to put an upper limit on the sizes of the files users can submit to - print. After all, there is only so much free space on the - filesystem that houses the spooling directories, and you also need - to make sure there is room for the jobs of other users. + + Format plain text with &man.pr.1; before printing. See + &man.pr.1; for more information. + + + + + - LPD enables you to limit the maximum byte size a file in a job - can be with the mx capability. The units are in - BUFSIZ blocks, which are 1024 bytes. If you put a zero for this - capability, there will be no limit on file size; however, if no - mx capability is specified, then a default limit - of 1000 blocks will be used. - - - The limit applies to files in a job, and - not the total job size. - - - LPD will not refuse a file that is larger than the limit you - place on a printer. Instead, it will queue as much of the file up - to the limit, which will then get printed. The rest will be - discarded. Whether this is correct behavior is up for - debate. + + Use title on the + &man.pr.1; header instead of the file name. This option has + effect only when used with the + option. + + + + + - Let us add limits to our example printers - rattan and bamboo. Since - those artists' PostScript files tend to be large, we will limit them - to five megabytes. We will put no limit on the plain text line - printer: - - -# -# /etc/printcap for host rose -# - -# -# No limit on job size: -# -rattan|line|diablo|lp|Diablo 630 Line Printer:\ - :sh:mx#0:sd=/var/spool/lpd/rattan:\ - :lp=/dev/lpt0:\ - :if=/usr/local/libexec/if-simple: - -# -# Limit of five megabytes: -# -bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4:\ - :sh:sd=/var/spool/lpd/bamboo:sc:rg=artists:mx#5000:\ - :lp=/dev/ttyd5:fs#0x82000e1:xs#0x820:rw:\ - :if=/usr/local/libexec/psif:\ - :df=/usr/local/libexec/psdf: - - Again, the limits apply to the local users only. If you have - set up access to your printers remotely, remote users will not get - those limits. You will need to specify the mx - capability in the remote /etc/printcap files as - well. See section Printers Installed on - Remote Hosts for more information on remote - printing. + + Print troff data. + + + + + + + + Print raster data. + + + + + Here is an example: this command prints a nicely formatted + version of the &man.ls.1; manual page on the default printer: + + &prompt.user; zcat /usr/share/man/man1/ls.1.gz | troff -t -man | lpr -t + + The &man.zcat.1; command uncompresses the source of the + + &man.ls.1; manual page and passes it to the &man.troff.1; + command, which formats that source and makes GNU troff output and + passes it to &man.lpr.1;, which submits the job to the LPD spooler. + Because we used the option to - There is another specialized way to limit job sizes from remote - printers; see section Restricting Jobs - from Remote Printers. + &man.lpr.1;, the spooler will convert the GNU troff output into + a format the default printer can understand when it prints the + job. - - Restricting Jobs from Remote Printers + + Job Handling Options - The LPD spooling system provides several ways to restrict print - jobs submitted from remote hosts: - + The following options to &man.lpr.1; tell LPD to handle the job + specially: + - Host restrictions + -# copies - You can control from which remote hosts a local LPD - accepts requests with the files - /etc/hosts.equiv and - /etc/hosts.lpd. LPD checks to see if an - incoming request is from a host listed in either one of these - files. If not, LPD refuses the request. - - The format of these files is simple: one host name per - line. Note that the file - /etc/hosts.equiv is also used by the - &man.ruserok.3; protocol, and affects programs like - &man.rsh.1; and &man.rcp.1;, so be careful. - - For example, here is the - /etc/hosts.lpd file on the host - rose: + Produce a number of copies of + each file in the job instead of just one copy. An + administrator may disable this option to reduce printer + wear-and-tear and encourage photocopier usage. See section + Restricting + Multiple Copies. - -orchid -violet -madrigal.fishbaum.de - - This means rose will accept requests from - the hosts orchid, violet, - and madrigal.fishbaum.de. If any - other host tries to access rose's LPD, LPD - will refuse them. + This example prints three copies of + parser.c followed by three copies of + parser.h to the default printer: + + &prompt.user; lpr -#3 parser.c parser.h + + + + + -m + + + Send mail after completing the print job. With this + option, the LPD system will send mail to your account when it + finishes handling your job. In its message, it will tell you + if the job completed successfully or if there was an error, + and (often) what the error was. - Size restrictions + -s - You can control how much free space there needs to remain - on the filesystem where a spooling directory resides. Make a - file called minfree in the spooling - directory for the local printer. Insert in that file a number - representing how many disk blocks (512 bytes) of free space - there has to be for a remote job to be accepted. + Do not copy the files to the spooling directory, but make + symbolic links to them instead. - This lets you insure that remote users will not fill your - filesystem. You can also use it to give a certain priority to - local users: they will be able to queue jobs long after the - free disk space has fallen below the amount specified in the - minfree file. + If you are printing a large job, you probably want to use + this option. It saves space in the spooling directory (your + job might overflow the free space on the filesystem where the + spooling directory resides). It saves time as well since LPD + will not have to copy each and every byte of your job to the + spooling directory. - For example, let us add a minfree - file for the printer bamboo. We examine - /etc/printcap to find the spooling - directory for this printer; here is bamboo's - entry: - - -bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4:\ - :sh:sd=/var/spool/lpd/bamboo:sc:rg=artists:mx#5000:\ - :lp=/dev/ttyd5:fs#0x82000e1:xs#0x820:rw:mx#5000:\ - :if=/usr/local/libexec/psif:\ - :df=/usr/local/libexec/psdf: + There is a drawback, though: since LPD will refer to the + original files directly, you cannot modify or remove them + until they have been printed. + + + If you are printing to a remote printer, LPD will + eventually have to copy files from the local host to the + remote host, so the option will save + space only on the local spooling directory, not the remote. + It is still useful, though. + + + + + + -r + + + Remove the files in the job after copying them to the + spooling directory, or after printing them with the + option. Be careful with this + option! + + + + + + + Header Page Options - The spooling directory is the given in the - sd capability. We will make three - megabytes (which is 6144 disk blocks) the amount of free disk - space that must exist on the filesystem for LPD to accept - remote jobs: - - &prompt.root; echo 6144 > /var/spool/lpd/bamboo/minfree + These options to &man.lpr.1; adjust the text that normally + appears on a job's header page. If header pages are suppressed for + the destination printer, these options have no effect. See section + Header Pages + for information about setting up header pages. + + + + -C text + + + Replace the hostname on the header page with + text. The hostname is normally the + name of the host from which the job was submitted. - User restrictions + -J text - You can control which remote users can print to local - printers by specifying the rs capability in - /etc/printcap. When - rs appears in the entry for a - locally-attached printer, LPD will accept jobs from remote - hosts if the user submitting the job also - has an account of the same login name on the local host. - Otherwise, LPD refuses the job. - - This capability is particularly useful in an environment - where there are (for example) different departments sharing a - network, and some users transcend departmental boundaries. By - giving them accounts on your systems, they can use your - printers from their own departmental systems. If you would - rather allow them to use only your - printers and not your compute resources, you can give them - “token” accounts, with no home directory and a - useless shell like /usr/bin/false. + Replace the job name on the header page with + text. The job name is normally the + name of the first file of the job, or + stdin if you are printing standard + input. + + + + + -h + + + Do not print any header page. + + + At some sites, this option may have no effect due to the + way header pages are generated. See Header + Pages for details. + - - Accounting for Printer Usage - - So, you need to charge for printouts. And why not? Paper and ink - cost money. And then there are maintenance costs—printers are - loaded with moving parts and tend to break down. You have examined - your printers, usage patterns, and maintenance fees and have come up - with a per-page (or per-foot, per-meter, or per-whatever) cost. Now, - how do you actually start accounting for printouts? - - Well, the bad news is the LPD spooling system does not provide - much help in this department. Accounting is highly dependent on the - kind of printer in use, the formats being printed, and - your requirements in charging for printer - usage. + + Administrating Printers - To implement accounting, you have to modify a printer's text - filter (to charge for plain text jobs) and the conversion filters (to - charge for other file formats), to count pages or query the printer - for pages printed. You cannot get away with using the simple output - filter, since it cannot do accounting. See section Filters. - - Generally, there are two ways to do accounting: + As an administrator for your printers, you have had to install, + set up, and test them. Using the &man.lpc.8; command, you + can interact with your printers in yet more ways. With &man.lpc.8;, + you can - Periodic accounting is the more common - way, possibly because it is easier. Whenever someone prints a - job, the filter logs the user, host, and number of pages to an - accounting file. Every month, semester, year, or whatever time - period you prefer, you collect the accounting files for the - various printers, tally up the pages printed by users, and charge - for usage. Then you truncate all the logging files, starting with - a clean slate for the next period. + Start and stop the printers - + + + Enable and disable their queues + + - Timely accounting is less common, - probably because it is more difficult. This method has the - filters charge users for printouts as soon as they use the - printers. Like disk quotas, the accounting is immediate. You can - prevent users from printing when their account goes in the red, - and might provide a way for users to check and adjust their - “print quotas.” But this method requires some database - code to track users and their quotas. + Rearrange the order of the jobs in each queue. - The LPD spooling system supports both methods easily: since you - have to provide the filters (well, most of the time), you also have to - provide the accounting code. But there is a bright side: you have - enormous flexibility in your accounting methods. For example, you - choose whether to use periodic or timely accounting. You choose what - information to log: user names, host names, job types, pages printed, - square footage of paper used, how long the job took to print, and so - forth. And you do so by modifying the filters to save this - information. + First, a note about terminology: if a printer is + stopped, it will not print anything in its queue. + Users can still submit jobs, which will wait in the queue until the + printer is started or the queue is + cleared. - - Quick and Dirty Printer Accounting - - FreeBSD comes with two programs that can get you set up with - simple periodic accounting right away. They are the text filter - lpf, described in section lpf: a Text Filter, and - &man.pac.8;, a program to gather and total - entries from printer accounting files. - - As mentioned in the section on filters (Filters), LPD starts - the text and the conversion filters with the name of the accounting - file to use on the filter command line. The filters can use this - argument to know where to write an accounting file entry. The name - of this file comes from the af capability in - /etc/printcap, and if not specified as an - absolute path, is relative to the spooling directory. - - LPD starts lpf with page width and length - arguments (from the pw and pl - capabilities). lpf uses these arguments to - determine how much paper will be used. After sending the file to - the printer, it then writes an accounting entry in the accounting - file. The entries look like this: - - -2.00 rose:andy -3.00 rose:kelly -3.00 orchid:mary -5.00 orchid:mary -2.00 orchid:zhang - - You should use a separate accounting file for each printer, as - lpf has no file locking logic built into it, and - two lpfs might corrupt each other's entries if - they were to write to the same file at the same time. A easy way to - insure a separate accounting file for each printer is to use - af=acct in /etc/printcap. - Then, each accounting file will be in the spooling directory for a - printer, in a file named acct. - - When you are ready to charge users for printouts, run the - &man.pac.8; program. Just change to the spooling directory for - the printer you want to collect on and type pac. - You will get a dollar-centric summary like the following: - - Login pages/feet runs price -orchid:kelly 5.00 1 $ 0.10 -orchid:mary 31.00 3 $ 0.62 -orchid:zhang 9.00 1 $ 0.18 -rose:andy 2.00 1 $ 0.04 -rose:kelly 177.00 104 $ 3.54 -rose:mary 87.00 32 $ 1.74 -rose:root 26.00 12 $ 0.52 + If a queue is disabled, no user (except root) + can submit jobs for the printer. An enabled + queue allows jobs to be submitted. A printer can be + started for a disabled queue, in which case it + will continue to print jobs in the queue until the queue is + empty. + + In general, you have to have root privileges to use the + &man.lpc.8; command. Ordinary users can use the &man.lpc.8; command + to get printer status and to restart a hung printer only. -total 337.00 154 $ 6.74 - - These are the arguments &man.pac.8; expects: + Here is a summary of the &man.lpc.8; commands. Most of the + commands takes a printer-name argument to + tell on which printer to operate. You can use all + for the printer-name to mean all printers + listed in /etc/printcap. + + + + abort + printer-name + + + Cancel the current job and stop the printer. Users can + still submit jobs if the queue's enabled. + + + + + clean + printer-name + + + Remove old files from the printer's spooling directory. + Occasionally, the files that make up a job are not properly + removed by LPD, particularly if there have been errors during + printing or a lot of administrative activity. This command + finds files that do not belong in the spooling directory and + removes them. + + + + + disable + printer-name + + + Disable queuing of new jobs. If the printer's started, it + will continue to print any jobs remaining in the queue. The + superuser (root) can always submit jobs, even to a disabled + queue. + + This command is useful while you are testing a new printer + or filter installation: disable the queue and submit jobs as + root. Other users will not be able to submit jobs until you + complete your testing and re-enable the queue with the + enable command. + + + + + down printer-name + message + + + Take a printer down. Equivalent to + disable followed by stop. + The message appears as the printer's + status whenever a user checks the printer's queue with + &man.lpq.1; or status with lpc + status. + + + + + enable + printer-name + + + Enable the queue for a printer. Users can submit jobs but + the printer will not print anything until it is started. + + - - - + + help + command-name + + + Print help on the command + command-name. With no + command-name, print a summary of the + commands available. + + - - Which printer to summarize. - This option works only if there is an absolute path in the - af capability in - /etc/printcap. - - - - - - - - Sort the output by cost instead of alphabetically by user - name. - - - - - - - - Ignore host name in the accounting files. With this - option, user smith on host - alpha is the same user - smith on host gamma. - Without, they are different users. - - - - - - - - Compute charges with price - dollars per page or per foot instead of the price from the - pc capability in - /etc/printcap, or two cents (the - default). You can specify price as - a floating point number. - - - - - - - - Reverse the sort order. - - - - - - - - Make an accounting summary file and truncate the - accounting file. - - + + restart + printer-name - - name - … - - - Print accounting information for the given user - names only. - - - + + Start the printer. Ordinary users can use this command if + some extraordinary circumstance hangs LPD, but they cannot start + a printer stopped with either the stop or + down commands. The + restart command is equivalent to + abort followed by + start. + + - In the default summary that &man.pac.8; produces, you see the - number of pages printed by each user from various hosts. If, at - your site, host does not matter (because users can use any host), - run pac -m, to produce the following - summary: - - Login pages/feet runs price -andy 2.00 1 $ 0.04 -kelly 182.00 105 $ 3.64 -mary 118.00 35 $ 2.36 -root 26.00 12 $ 0.52 -zhang 9.00 1 $ 0.18 + + start + printer-name + + + Start the printer. The printer will print jobs in its + queue. + + -total 337.00 154 $ 6.74 - + + stop + printer-name + + + Stop the printer. The printer will finish the current job + and will not print anything else in its queue. Even though the + printer is stopped, users can still submit jobs to an enabled + queue. + + - To compute the dollar amount due, - &man.pac.8; uses the pc capability in the - /etc/printcap file (default of 200, or 2 cents - per page). Specify, in hundredths of cents, the price per page or - per foot you want to charge for printouts in this capability. You - can override this value when you run &man.pac.8; with the - option. The units for the - option are in dollars, though, not hundredths of cents. For - example, - - &prompt.root; pac -p1.50 - - makes each page cost one dollar and fifty cents. You can really - rake in the profits by using this option. - - Finally, running pac -s will save the summary - information in a summary accounting file, which is named the same as - the printer's accounting file, but with _sum - appended to the name. It then truncates the accounting file. When - you run &man.pac.8; again, it rereads the - summary file to get starting totals, then adds information from the - regular accounting file. - - - - How Can You Count Pages Printed? + + topq printer-name + job-or-username + + + Rearrange the queue for + printer-name by placing the jobs with + the listed job numbers or the jobs + belonging to username at the top of + the queue. For this command, you cannot use + all as the + printer-name. + + - In order to perform even remotely accurate accounting, you need - to be able to determine how much paper a job uses. This is the - essential problem of printer accounting. - - For plain text jobs, the problem's not that hard to solve: you - count how many lines are in a job and compare it to how many lines - per page your printer supports. Do not forget to take into account - backspaces in the file which overprint lines, or long logical lines - that wrap onto one or more additional physical lines. - - The text filter lpf (introduced in lpf: a Text Filter) takes - into account these things when it does accounting. If you are - writing a text filter which needs to do accounting, you might want - to examine lpf's source code. - - How do you handle other file formats, though? - - Well, for DVI-to-LaserJet or DVI-to-PostScript conversion, you - can have your filter parse the diagnostic output of - dvilj or dvips and look to see - how many pages were converted. You might be able to do similar - things with other file formats and conversion programs. - - But these methods suffer from the fact that the printer may not - actually print all those pages. For example, it could jam, run out - of toner, or explode—and the user would still get - charged. - - So, what can you do? - - There is only one sure way to do - accurate accounting. Get a printer that can - tell you how much paper it uses, and attach it via a serial line or - a network connection. Nearly all PostScript printers support this - notion. Other makes and models do as well (networked Imagen laser - printers, for example). Modify the filters for these printers to - get the page usage after they print each job and have them log - accounting information based on that value - only. There is no line counting nor - error-prone file examination required. - - Of course, you can always be generous and make all printouts - free. - + + up + printer-name + + + Bring a printer up; the opposite of the + down command. Equivalent to + start followed by + enable. + + + + + &man.lpc.8; accepts the above commands on the command line. If + you do not enter any commands, &man.lpc.8; enters an interactive mode, + where you can enter commands until you type exit, + quit, or end-of-file. Alternatives to the Standard Spooler If you have been reading straight through this manual, by now you have learned just about everything there is to know about the LPD spooling system that comes with FreeBSD. You can probably appreciate many of its shortcomings, which naturally leads to the question: “What other spooling systems are out there (and work with FreeBSD)?” Unfortunately, I have located only two alternatives—and they are almost identical to each other! They are: PLP, the Portable Line Printer Spooler System PLP was based on software developed by Patrick Powell and then maintained by an Internet-wide group of developers. The main site for the software is at ftp://ftp.iona.ie/pub/plp/. There is also a web page. It is quite similar to the BSD LPD spooler, but boasts a host of features, including: Better network support, including built-in support for networked printers, NIS-maintained printcaps, and NFS-mounted spooling directories Sophisticated queue management, allowing multiple printers on a queue, transfer of jobs between queues, and queue redirection Remote printer control functions Prioritization of jobs Expansive security and access options LPRng LPRng, which purportedly means “LPR: the Next Generation” is a complete rewrite of PLP. Patrick Powell and Justin Mason (the principal maintainer of PLP) collaborated to make LPRng. The main site for LPRng is ftp://dickory.sdsu.edu/pub/LPRng/. - - - Acknowledgments - - I would like to thank the following people who have assisted in the - development of this document: + + + Troubleshooting + + After performing the simple test with &man.lptest.1;, you might + have gotten one of the following results instead of the correct + printout: - Daniel Eischen - deischen@iworks.interworks.org + It worked, after awhile; or, it did not eject a full + sheet. - For providing a plethora of HP filter programs for - perusal. + The printer printed the above, but it sat for awhile and + did nothing. In fact, you might have needed to press a + PRINT REMAINING or FORM FEED button on the printer to get any + results to appear. + + If this is the case, the printer was probably waiting to + see if there was any more data for your job before it printed + anything. To fix this problem, you can have the text filter + send a FORM FEED character (or whatever is necessary) to the + printer. This is usually sufficient to have the printer + immediately print any text remaining in its internal buffer. + It is also useful to make sure each print job ends on a full + sheet, so the next job does not start somewhere on the middle + of the last page of the previous job. + + The following replacement for the shell script + /usr/local/libexec/if-simple prints a + form feed after it sends the job to the printer: + + +#!/bin/sh +# +# if-simple - Simple text input filter for lpd +# Installed in /usr/local/libexec/if-simple +# +# Simply copies stdin to stdout. Ignores all filter arguments. +# Writes a form feed character (\f) after printing job. + +/bin/cat && printf "\f" && exit 0 +exit 2 - + + + It produced the “staircase effect.” + + + You got the following on paper: + + +!"#$%&'()*+,-./01234 + "#$%&'()*+,-./012345 + #$%&'()*+,-./0123456 + + You have become another victim of the staircase + effect, caused by conflicting interpretations of + what characters should indicate a new line. UNIX-style + operating systems use a single character: ASCII code 10, the + line feed (LF). MS-DOS, OS/2, and others uses a pair of + characters, ASCII code 10 and ASCII code + 13 (the carriage return or CR). Many printers use the MS-DOS + convention for representing new-lines. + + When you print with FreeBSD, your text used just the line + feed character. The printer, upon seeing a line feed + character, advanced the paper one line, but maintained the + same horizontal position on the page for the next character + to print. That is what the carriage return is for: to move + the location of the next character to print to the left edge + of the paper. + + Here is what FreeBSD wants your printer to do: + + + + + + Printer received CR + Printer prints CR + + + + Printer received LF + Printer prints CR + LF + + + + + + Here are some ways to achieve this: + + + + Use the printer's configuration switches or control + panel to alter its interpretation of these characters. + Check your printer's manual to find out how to do + this. + + + If you boot your system into other operating systems + besides FreeBSD, you may have to + reconfigure the printer to use a an + interpretation for CR and LF characters that those other + operating systems use. You might prefer one of the other + solutions, below. + + + + + Have FreeBSD's serial line driver automatically + convert LF to CR+LF. Of course, this works with printers + on serial ports only. To enable this + feature, set the CRMOD bit in fs + capability in the /etc/printcap file + for the printer. + + + + Send an escape code to the + printer to have it temporarily treat LF characters + differently. Consult your printer's manual for escape + codes that your printer might support. When you find the + proper escape code, modify the text filter to send the + code first, then send the print job. + + Here is an example text filter for printers that + understand the Hewlett-Packard PCL escape codes. This + filter makes the printer treat LF characters as a LF and + CR; then it sends the job; then it sends a form feed to + eject the last page of the job. It should work with + nearly all Hewlett Packard printers. + + +#!/bin/sh +# +# hpif - Simple text input filter for lpd for HP-PCL based printers +# Installed in /usr/local/libexec/hpif +# +# Simply copies stdin to stdout. Ignores all filter arguments. +# Tells printer to treat LF as CR+LF. Ejects the page when done. + +printf "\033&k2G" && cat && printf "\033&l0H" && exit 0 +exit 2 + + Here is an example /etc/printcap + from a host called orchid. It has a single printer + attached to its first parallel port, a Hewlett Packard + LaserJet 3Si named teak. It is using the + above script as its text filter: + + +# +# /etc/printcap for host orchid +# +teak|hp|laserjet|Hewlett Packard LaserJet 3Si:\ + :lp=/dev/lpt0:sh:sd=/var/spool/lpd/teak:mx#0:\ + :if=/usr/local/libexec/hpif: + + + + + - &a.jehamby; + It overprinted each line. - For the Ghostscript-to-HP filter. + The printer never advanced a line. All of the lines of + text were printed on top of each other on one line. + + This problem is the “opposite” of the + staircase effect, described above, and is much rarer. + Somewhere, the LF characters that FreeBSD uses to end a line + are being treated as CR characters to return the print + location to the left edge of the paper, but not also down a + line. + + Use the printer's configuration switches or control panel + to enforce the following interpretation of LF and CR + characters: + + + + + + Printer receives + Printer prints + + + + + + CR + CR + + + + LF + CR + LF + + + + - &a.jfieber; + The printer lost characters. - For debugging why printing from Windows 95 to a FreeBSD - system simulating a PostScript printer with Ghostscript didn't - produce correct output, and suggesting a fix, which is included - herein. + While printing, the printer did not print a few characters + in each line. The problem might have gotten worse as the + printer ran, losing more and more characters. + + The problem is that the printer cannot keep up with the + speed at which the computer sends data over a serial line + (this problem should not occur with printers on parallel + ports). There are two ways to overcome the problem: + + + + If the printer supports XON/XOFF flow control, have + FreeBSD use it by specifying the TANDEM bit in the + fs capability. + + + + If the printer supports carrier flow control, specify + the MDMBUF bit in the fs capability. + Make sure the cable connecting the printer to the computer + is correctly wired for carrier flow control. + + + + If the printer does not support any flow control, use + some combination of the NLDELAY, TBDELAY, CRDELAY, VTDELAY, + and BSDELAY bits in the fs capability + to add appropriate delays to the stream of data sent to + the printer. + + - Stephen Montgomery-Smith - stephen@math.missouri.edu + It printed garbage. - For suggesting using "\033&l0H" instead of "\f" to eject - the last page on HP printers; the latter could eject an extra - blank page while the former never does. + The printer printed what appeared to be random garbage, + but not the desired text. + + This is usually another symptom of incorrect + communications parameters with a serial printer. Double-check + the bps rate in the br capability, and the + parity bits in the fs and + fc capabilities; make sure the printer is + using the same settings as specified in the + /etc/printcap file. - + - My wife, Mary Kelly - urquhart@argyre.colorado.edu + Nothing happened. - For allowing me to spend more time with FreeBSD than - with her. + If nothing happened, the problem is probably within + FreeBSD and not the hardware. Add the log file + (lf) capability to the entry for the + printer you are debugging in the + /etc/printcap file. For example, here is + the entry for rattan, with the + lf capability: + + +rattan|line|diablo|lp|Diablo 630 Line Printer:\ + :sh:sd=/var/spool/lpd/rattan:\ + :lp=/dev/lpt0:\ + :if=/usr/local/libexec/if-simple:\ + :lf=/var/log/rattan.log + + Then, try printing again. Check the log file (in our + example, /var/log/rattan.log) to see any + error messages that might appear. Based on the messages you + see, try to correct the problem. + + If you do not specify a lf capability, + LPD uses /dev/console as a + default. diff --git a/en_US.ISO_8859-1/books/handbook/printing/chapter.sgml b/en_US.ISO_8859-1/books/handbook/printing/chapter.sgml index 596b90c8eb..faff1afa92 100644 --- a/en_US.ISO_8859-1/books/handbook/printing/chapter.sgml +++ b/en_US.ISO_8859-1/books/handbook/printing/chapter.sgml @@ -1,4672 +1,4644 @@ Printing - - Contributed by &a.kelly; 30 September - 1995 - - In order to use printers with FreeBSD, you will need to set them up to - work with the Berkeley line printer spooling system, also known as the LPD - spooling system. It is the standard printer control system in FreeBSD. - This section introduces the LPD spooling system, often simply called - LPD. - - If you are already familiar with LPD or another printer spooling - system, you may wish to skip to section Restructured and updated by &a.jim;, March + 2000. + + + Synopsis + + In order to use printers with FreeBSD, you will need to set them + up to work with the Berkeley line printer spooling system, also + known as the LPD spooling system. It is the standard printer + control system in FreeBSD. This chapter introduces the LPD spooling + system, often simply called LPD, and will guide you through it's + configuration. + + If you are already familiar with LPD or another printer spooling + system, you may wish to skip to section Setting up the spooling system. - + + - What the Spooler Does + Introduction - LPD controls everything about a host's printers. It is responsible - for a number of things: + LPD controls everything about a host's printers. It is + responsible for a number of things: - It controls access to attached printers and printers attached to - other hosts on the network. + It controls access to attached printers and printers + attached to other hosts on the network. - + It enables users to submit files to be printed; these submissions are known as jobs. - + - It prevents multiple users from accessing a printer at the same - time by maintaining a queue for each + It prevents multiple users from accessing a printer at the + same time by maintaining a queue for each printer. - + - It can print header pages (also known as - banner or burst pages) so - users can easily find jobs they have printed in a stack of - printouts. + It can print header pages (also known + as banner or burst + pages) so users can easily find jobs they have printed in a + stack of printouts. - + It takes care of communications parameters for printers connected on serial ports. - + It can send jobs over the network to another LPD spooler on another host. - + It can run special filters to format jobs to be printed for various printer languages or printer capabilities. - + It can account for printer usage. - - Through a configuration file, and by providing the special filter - programs, you can enable the LPD system to do all or some subset of the - above for a great variety of printer hardware. - - - - Why You Should Use the Spooler - - If you are the sole user of your system, you may be wondering why - you should bother with the spooler when you do not need access control, - header pages, or printer accounting. While it is possible to enable - direct access to a printer, you should use the spooler anyway - since - - - - LPD prints jobs in the background; you do not have to wait for - data to be copied to the printer. - - - - LPD can conveniently run a job to be printed through filters to - add date/time headers or convert a special file format (such as a - TeX DVI file) into a format the printer will understand. You will - not have to do these steps manually. - - - - Many free and commercial programs that provide a print feature - usually expect to talk to the spooler on your system. By setting up - the spooling system, you will more easily support other software you - may later add or already have. - - + + Through a configuration file + (/etc/printcap), and by providing the special + filter programs, you can enable the LPD system to do all or some + subset of the above for a great variety of printer hardware. + + + Why You Should Use the Spooler + + If you are the sole user of your system, you may be wondering + why you should bother with the spooler when you do not need access + control, header pages, or printer accounting. While it is + possible to enable direct access to a printer, you should use the + spooler anyway since: + + + + LPD prints jobs in the background; you do not have to wait + for data to be copied to the printer. + + + + LPD can conveniently run a job to be printed through + filters to add date/time headers or convert a special file + format (such as a TeX DVI file) into a format the printer will + understand. You will not have to do these steps + manually. + + + + Many free and commercial programs that provide a print + feature usually expect to talk to the spooler on your system. + By setting up the spooling system, you will more easily + support other software you may later add or already + have. + + + - + - Setting Up the Spooling System - - To use printers with the LPD spooling system, you will need to set - up both your printer hardware and the LPD software. This document - describes two levels of setup: - + Basic Setup + + To use printers with the LPD spooling system, you will need to + set up both your printer hardware and the LPD software. This + document describes two levels of setup: + See section Simple Printer - Setup to learn how to connect a printer, tell LPD how to + Setup to learn how to connect a printer, tell LPD how to communicate with it, and print plain text files to the printer. - - - See section Advanced Printer - Setup to find out how to print a variety of special file - formats, to print header pages, to print across a network, to - control access to printers, and to do printer accounting. - - - - - - Simple Printer Setup - - This section tells how to configure printer hardware and the LPD - software to use the printer. It teaches the basics: - - - - Section Hardware Setup - gives some hints on connecting the printer to a port on your - computer. - - + - Section Software Setup - shows how to setup the LPD spooler configuration file - /etc/printcap. + See section Advanced + Printer Setup to find out how to print a variety of + special file formats, to print header pages, to print across a + network, to control access to printers, and to do printer + accounting. - - If you are setting up a printer that uses a network protocol to - accept data to print instead of a serial or parallel interface, see - Printers With Networked - Data Stream Interaces. - - Although this section is called “Simple Printer Setup,” - it is actually fairly complex. Getting the printer to work with your - computer and the LPD spooler is the hardest part. The advanced options - like header pages and accounting are fairly easy once you get the - printer working. - - - Hardware Setup - - This section tells about the various ways you can connect a - printer to your PC. It talks about the kinds of ports and cables, and - also the kernel configuration you may need to enable FreeBSD to speak - to the printer. - - If you have already connected your printer and have successfully - printed with it under another operating system, you can probably skip - to section Software - Setup. - - - Ports and Cables - Nearly all printers you can get for a PC today support one or - both of the following interfaces: - - - - Serial interfaces use a serial port on - your computer to send data to the printer. Serial interfaces - are common in the computer industry and cables are readily - available and also easy to construct. Serial interfaces - sometimes need special cables and might require you to configure - somewhat complex communications options. - - - - Parallel interfaces use a parallel port - on your computer to send data to the printer. Parallel - interfaces are common in the PC market. Cables are readily - available but more difficult to construct by hand. There are - usually no communications options with parallel interfaces, - making their configuration exceedingly simple. - - Parallel interfaces are sometimes known as - “Centronics” interfaces, named after the connector - type on the printer. - - - - In general, serial interfaces are slower than parallel - interfaces. Parallel interfaces usually offer just one-way - communication (computer to printer) while serial gives you two-way. - Many newer parallel ports can also receive data from the printer, - but only few printers need to send data back to the computer. And - FreeBSD does not support two-way parallel communication yet. - - Usually, the only time you need two-way communication with the - printer is if the printer speaks PostScript. PostScript printers - can be very verbose. In fact, PostScript jobs are actually programs - sent to the printer; they need not produce paper at all and may - return results directly to the computer. PostScript also uses - two-way communication to tell the computer about problems, such as - errors in the PostScript program or paper jams. Your users may be - appreciative of such information. Furthermore, the best way to do - effective accounting with a PostScript printer requires two-way - communication: you ask the printer for its page count (how many - pages it has printed in its lifetime), then send the user's job, - then ask again for its page count. Subtract the two values and you - know how much paper to charge the user. - - So, which interface should you use? - - - - If you need two-way communication, use a serial port. - FreeBSD does not yet support two-way communication over a - parallel port. - - - - If you do not need two-way communication and can pick - parallel or serial, prefer the parallel interface. It keeps a - serial port free for other peripherals—such as a terminal - or a modem—and is faster most of the time. It is also - easier to configure. - - - - Finally, use whatever works. - - - - - - Parallel Ports + + Simple Printer Setup - To hook up a printer using a parallel interface, connect the - Centronics cable between the printer and the computer. The - instructions that came with the printer, the computer, or both - should give you complete guidance. - - Remember which parallel port you used on the computer. The - first parallel port is /dev/lpt0 to FreeBSD; - the second is /dev/lpt1, and so on. - + This section tells how to configure printer hardware and the + LPD software to use the printer. It teaches the basics: + + + + Section Hardware + Setup gives some hints on connecting the printer to a + port on your computer. + + + + Section Software + Setup shows how to setup the LPD spooler configuration + file (/etc/printcap). + + + + If you are setting up a printer that uses a network protocol + to accept data to print instead of a serial or parallel interface, + see Printers With + Networked Data Stream Interaces. + + Although this section is called “Simple Printer + Setup”, it is actually fairly complex. Getting the printer + to work with your computer and the LPD spooler is the hardest + part. The advanced options like header pages and accounting are + fairly easy once you get the printer working. + + + Hardware Setup + + This section tells about the various ways you can connect a + printer to your PC. It talks about the kinds of ports and + cables, and also the kernel configuration you may need to enable + FreeBSD to speak to the printer. + + If you have already connected your printer and have + successfully printed with it under another operating system, you + can probably skip to section Software Setup. + + + Ports and Cables + + Nearly all printers you can get for a PC today support one + or both of the following interfaces: + + + + Serial interfaces use a serial + port on your computer to send data to the printer. Serial + interfaces are common in the computer industry and cables + are readily available and also easy to construct. Serial + interfaces sometimes need special cables and might require + you to configure somewhat complex communications + options. + + + + Parallel interfaces use a + parallel port on your computer to send data to the + printer. Parallel interfaces are common in the PC market. + Cables are readily available but more difficult to + construct by hand. There are usually no communications + options with parallel interfaces, making their + configuration exceedingly simple. + + Parallel interfaces are sometimes known as + “Centronics” interfaces, named after the + connector type on the printer. + + + + In general, serial interfaces are slower than parallel + interfaces. Parallel interfaces usually offer just one-way + communication (computer to printer) while serial gives you + two-way. Many newer parallel ports can also receive data from + the printer, but only few printers need to send data back to + the computer. And FreeBSD does not support two-way parallel + communication yet. + + Usually, the only time you need two-way communication with + the printer is if the printer speaks PostScript. PostScript + printers can be very verbose. In fact, PostScript jobs are + actually programs sent to the printer; they need not produce + paper at all and may return results directly to the computer. + PostScript also uses two-way communication to tell the + computer about problems, such as errors in the PostScript + program or paper jams. Your users may be appreciative of such + information. Furthermore, the best way to do effective + accounting with a PostScript printer requires two-way + communication: you ask the printer for its page count (how + many pages it has printed in its lifetime), then send the + user's job, then ask again for its page count. Subtract the + two values and you know how much paper to charge the + user. + - - Serial Ports + + Parallel Ports + + To hook up a printer using a parallel interface, connect + the Centronics cable between the printer and the computer. + The instructions that came with the printer, the computer, or + both should give you complete guidance. + + Remember which parallel port you used on the computer. + The first parallel port is /dev/lpt0 to + FreeBSD; the second is /dev/lpt1, and so + on. + - To hook up a printer using a serial interface, connect the - proper serial cable between the printer and the computer. The - instructions that came with the printer, the computer, or both - should give you complete guidance. + + Serial Ports - If you are unsure what the “proper serial cable” is, - you may wish to try one of the following alternatives: + To hook up a printer using a serial interface, connect the + proper serial cable between the printer and the computer. The + instructions that came with the printer, the computer, or both + should give you complete guidance. - - - A modem cable connects each pin of the - connector on one end of the cable straight through to its - corresponding pin of the connector on the other end. This type - of cable is also known as a “DTE-to-DCE” - cable. - - - - A null-modem cable connects some pins - straight through, swaps others (send data to receive data, for - example), and shorts some internally in each connector hood. - This type of cable is also known as a “DTE-to-DTE” - cable. - - - - A serial printer cable, required for - some unusual printers, is like the null modem cable, but sends - some signals to their counterparts instead of being internally - shorted. - - - - You should also set up the communications parameters for the - printer, usually through front-panel controls or DIP switches on the - printer. Choose the highest bps (bits per second, sometimes - baud rate) rate that both your computer and the - printer can support. Choose 7 or 8 data bits; none, even, or odd - parity; and 1 or 2 stop bits. Also choose a flow control protocol: - either none, or XON/XOFF (also known as “in-band” or - “software”) flow control. Remember these settings for - the software configuration that follows. + If you are unsure what the “proper serial + cable” is, you may wish to try one of the following + alternatives: + + + + A modem cable connects each pin + of the connector on one end of the cable straight through + to its corresponding pin of the connector on the other + end. This type of cable is also known as a + “DTE-to-DCE” cable. + + + + A null-modem cable connects some + pins straight through, swaps others (send data to receive + data, for example), and shorts some internally in each + connector hood. This type of cable is also known as a + “DTE-to-DTE” cable. + + + + A serial printer cable, required + for some unusual printers, is like the null modem cable, + but sends some signals to their counterparts instead of + being internally shorted. + + + + You should also set up the communications parameters for + the printer, usually through front-panel controls or DIP + switches on the printer. Choose the highest + bps (bits per second, sometimes + baud rate) rate that both your computer + and the printer can support. Choose 7 or 8 data bits; none, + even, or odd parity; and 1 or 2 stop bits. Also choose a flow + control protocol: either none, or XON/XOFF (also known as + “in-band” or “software”) flow control. + Remember these settings for the software configuration that + follows. + - - - - Software Setup - - This section describes the software setup necessary to print - with the LPD spooling system in FreeBSD. - - Here is an outline of the steps involved: - - - - Configure your kernel, if necessary, for the port you are - using for the printer; section Kernel Configuration tells you - what you need to do. - - - - Set the communications mode for the parallel port, if you are - using a parallel port; section Setting the Communication - Mode for the Parallel Port gives details. - - - - Test if the operating system can send data to the printer. - Section Checking Printer + + + Software Setup + + This section describes the software setup necessary to print + with the LPD spooling system in FreeBSD. + + Here is an outline of the steps involved: + + + + Configure your kernel, if necessary, for the port you + are using for the printer; section Kernel Configuration tells + you what you need to do. + + + + Set the communications mode for the parallel port, if + you are using a parallel port; section Setting the + Communication Mode for the Parallel Port gives + details. + + + + Test if the operating system can send data to the printer. + Section Checking Printer Communications gives some suggestions on how to do - this. - - - - Set up LPD for the printer by modifying the file - /etc/printcap. Section The /etc/printcap File shows - you how. - - - - - Kernel Configuration - - The operating system kernel is compiled to work with a specific - set of devices. The serial or parallel interface for your printer - is a part of that set. Therefore, it might be necessary to add - support for an additional serial or parallel port if your kernel is - not already configured for one. - - To find out if the kernel you are currently using supports a - serial interface, type: - - &prompt.root; dmesg | grep sioN - - Where N is the number of the serial - port, starting from zero. If you see output similar to the - following: + this. + + + + Set up LPD for the printer by modifying the file + /etc/printcap. You will find out how + to do this later in this chapter. + + + + + Kernel Configuration + + The operating system kernel is compiled to work with a + specific set of devices. The serial or parallel interface for + your printer is a part of that set. Therefore, it might be + necessary to add support for an additional serial or parallel + port if your kernel is not already configured for one. - sio2 at 0x3e8-0x3ef irq 5 on isa + To find out if the kernel you are currently using supports + a serial interface, type: + + &prompt.root; dmesg | grep sioN + + Where N is the number of the + serial port, starting from zero. If you see output similar to + the following: + + sio2 at 0x3e8-0x3ef irq 5 on isa sio2: type 16550A - - then the kernel supports the port. - To find out if the kernel supports a parallel interface, - type: + then the kernel supports the port. - &prompt.root; dmesg | grep lptN - - Where N is the number of the parallel - port, starting from zero. If you see output similar to the - following lpt0 at 0x378-0x37f on isa then the - kernel supports the port. - - You might have to reconfigure your kernel in order for the - operating system to recognize and use the parallel or serial port - you are using for the printer. - - To add support for a serial port, see the section on kernel - configuration. To add support for a parallel port, see that section - and the section that follows. - - - Adding <filename>/dev</filename> Entries for the Ports - - Even though the kernel may support communication along a - serial or parallel port, you will still need a software interface - through which programs running on the system can send and receive - data. That is what entries in the /dev - directory are for. - - To add a /dev entry for a - port: - - - - Become root with the &man.su.1; command. Enter the root - password when prompted. - - - - Change to the /dev directory: - - &prompt.root; cd /dev - - - - - Type: - - &prompt.root; ./MAKEDEV port - - Where port is the device entry - for the port you want to make. Use lpt0 - for the first parallel port, lpt1 for the - second, and so on; use ttyd0 for the first - serial port, ttyd1 for the second, and so - on. - - - - Type: - - &prompt.root; ls -l port - - to make sure the device entry got created. - - + To find out if the kernel supports a parallel interface, + type: + + &prompt.root; dmesg | grep lptN + + Where N is the number of the + parallel port, starting from zero. If you see output similar + to the following lpt0 at 0x378-0x37f on isa + then the kernel supports the port. + + You might have to reconfigure your kernel in order for the + operating system to recognize and use the parallel or serial + port you are using for the printer. + + To add support for a serial port, see the section on + kernel configuration. To add support for a parallel port, see + that section and the section that + follows. + + + + Adding <filename>/dev</filename> Entries for the + Ports + + Even though the kernel may support communication along a + serial or parallel port, you will still need a software + interface through which programs running on the system can + send and receive data. That is what entries in the + /dev directory are for. + + To add a /dev entry for a + port: + + + + Become root with the &man.su.1; command. Enter the + root password when prompted. + + + + Change to the /dev + directory: + + &prompt.root; cd /dev + + + + Type: + + &prompt.root; ./MAKEDEV port + + Where port is the device + entry for the port you want to make. Use + lpt0 for the first parallel port, + lpt1 for the second, and so on; use + ttyd0 for the first serial port, + ttyd1 for the second, and so on. + + + + Type: + + &prompt.root; ls -l port + + to make sure the device entry got created. + + - Setting the Communication Mode for the Parallel Port - + Setting the Communication Mode for the Parallel + Port + When you are using the parallel interface, you can choose whether FreeBSD should use interrupt-driven or polled communication with the printer. - + - The interrupt-driven method is the - default with the GENERIC kernel. With this method, the - operating system uses an IRQ line to determine when the - printer is ready for data. + The interrupt-driven method is + the default with the GENERIC kernel. With this method, + the operating system uses an IRQ line to determine when + the printer is ready for data. - + The polled method directs the - operating system to repeatedly ask the printer if it is ready - for more data. When it responds ready, the kernel sends more - data. + operating system to repeatedly ask the printer if it is + ready for more data. When it responds ready, the kernel + sends more data. - - The interrupt-driven method is somewhat faster but uses up a - precious IRQ line. You should use whichever one works. - + + The interrupt-driven method is somewhat faster but uses up + a precious IRQ line. You should use whichever one + works. + You can set the communications mode in two ways: by configuring the kernel or by using the &man.lptcontrol.8; program. - - To set the communications mode by configuring the - kernel: - + + To set the communications mode by configuring + the kernel: + - Edit your kernel configuration file. Look for or add an - lpt0 entry. If you are setting up the - second parallel port, use lpt1 instead. - Use lpt2 for the third port, and so - on. - + Edit your kernel configuration file. Look for or add + an lpt0 entry. If you are setting up + the second parallel port, use lpt1 + instead. Use lpt2 for the third port, + and so on. + If you want interrupt-driven mode, add the irq specifier: - + device lpt0 at isa? port? tty irq N vector lptintr - Where N is the IRQ number - for your computer's parallel port. + Where N is the IRQ + number for your computer's parallel port. - + If you want polled mode, do not add the irq specifier: - + device lpt0 at isa? port? tty vector lptintr - + Save the file. Then configure, build, and install the - kernel, then reboot. See kernel - configuration for more details. + kernel, then reboot. See kernel configuration for + more details. - + To set the communications mode with - &man.lptcontrol.8;: - + &man.lptcontrol.8;: + Type: - + &prompt.root; lptcontrol -i -u N - + to set interrupt-driven mode for lptN. - + Type: - + &prompt.root; lptcontrol -p -u N - + to set polled-mode for lptN. - + You could put these commands in your - /etc/rc.local file to set the mode each time - your system boots. See &man.lptcontrol.8; for more + /etc/rc.local file to set the mode each + time your system boots. See &man.lptcontrol.8; for more information. Checking Printer Communications - - Before proceeding to configure the spooling system, you should - make sure the operating system can successfully send data to your - printer. It is a lot easier to debug printer communication and - the spooling system separately. - + + Before proceeding to configure the spooling system, you + should make sure the operating system can successfully send + data to your printer. It is a lot easier to debug printer + communication and the spooling system separately. + To test the printer, we will send some text to it. For printers that can immediately print characters sent to them, the program &man.lptest.1; is perfect: it generates all 96 printable ASCII characters in 96 lines. - - For a PostScript (or other language-based) printer, we will - need a more sophisticated test. A small PostScript program, such - as the following, will suffice: + + For a PostScript (or other language-based) printer, we + will need a more sophisticated test. A small PostScript + program, such as the following, will suffice: %!PS 100 100 moveto 300 300 lineto stroke 310 310 moveto /Helvetica findfont 12 scalefont setfont (Is this thing working?) show showpage - + - When this document refers to a printer language, I am - assuming a language like PostScript, and not Hewlett Packard's - PCL. Although PCL has great functionality, you can intermingle - plain text with its escape sequences. PostScript cannot directly - print plain text, and that is the kind of printer language for - which we must make special accommodations. - - + When this document refers to a printer language, it is + assuming a language like PostScript, and not Hewlett + Packard's PCL. Although PCL has great functionality, you + can intermingle plain text with its escape sequences. + PostScript cannot directly print plain text, and that is the + kind of printer language for which we must make special + accommodations. + + Checking a Parallel Printer - + This section tells you how to check if FreeBSD can - communicate with a printer connected to a parallel port. - + communicate with a printer connected to a parallel + port. + To test a printer on a parallel - port: - + port: + Become root with &man.su.1;. - + Send data to the printer. If the printer can print plain text, then use - &man.lptest.1;. Type: - + &man.lptest.1;. Type: + &prompt.root; lptest > /dev/lptN - - Where N is the number of - the parallel port, starting from zero. + + Where N is the number + of the parallel port, starting from zero. - + If the printer understands PostScript or other printer language, then send a small program to the printer. Type: - + &prompt.root; cat > /dev/lptN - + Then, line by line, type the program - carefully as you cannot edit a line - once you have pressed RETURN or ENTER. When you have - finished entering the program, press CONTROL+D, or - whatever your end of file key is. - - Alternatively, you can put the program in a file and - type: - + carefully as you cannot edit a + line once you have pressed RETURN + or ENTER. When you have finished + entering the program, press + CONTROL+D, or whatever your end + of file key is. + + Alternatively, you can put the program in a file + and type: + &prompt.root; cat file > /dev/lptN - - Where file is the name of - the file containing the program you want to send to the - printer. + + Where file is the + name of the file containing the program you want to + send to the printer. - - You should see something print. Do not worry if the text - does not look right; we will fix such things later. + + You should see something print. Do not worry if the + text does not look right; we will fix such things + later. - + Checking a Serial Printer - + This section tells you how to check if FreeBSD can communicate with a printer on a serial port. - + To test a printer on a serial - port: - + port: + Become root with &man.su.1;. - + - Edit the file /etc/remote. Add the - following entry: - + Edit the file /etc/remote. Add + the following entry: + printer:dv=/dev/port:br#bps-rate:pa=parity Where port is the device entry for the serial port (ttyd0, ttyd1, etc.), - bps-rate is the bits-per-second - rate at which the printer communicates, and - parity is the parity required by - the printer (either even, + bps-rate is the + bits-per-second rate at which the printer communicates, + and parity is the parity + required by the printer (either even, odd, none, or zero). - - Here is a sample entry for a printer connected via a - serial line to the third serial port at 19200 bps with no - parity: - + + Here is a sample entry for a printer connected via + a serial line to the third serial port at 19200 bps with + no parity: + printer:dv=/dev/ttyd2:br#19200:pa=none - + - Connect to the printer with &man.tip.1;. Type: - + Connect to the printer with &man.tip.1;. + Type: + &prompt.root; tip printer - + If this step does not work, edit the file /etc/remote again and try using /dev/cuaaN instead of /dev/ttydN. - + Send data to the printer. If the printer can print plain text, then use - &man.lptest.1;. Type: - + &man.lptest.1;. Type: + ~$lptest - + If the printer understands PostScript or other printer language, then send a small program to the - printer. Type the program, line by line, very - carefully as backspacing or other editing - keys may be significant to the printer. You may also - need to type a special end-of-file key for the printer - so it knows it received the whole program. For - PostScript printers, press CONTROL+D. - - Alternatively, you can put the program in a file and - type: - + printer. Type the program, line by line, + very carefully as backspacing + or other editing keys may be significant to the + printer. You may also need to type a special + end-of-file key for the printer so it knows it + received the whole program. For PostScript + printers, press CONTROL+D. + + Alternatively, you can put the program in a file + and type: + ~>file - - Where file is the name of - the file containing the program. After - &man.tip.1; sends the file, press any required + + Where file is the + name of the file containing the program. After + &man.tip.1; sends the file, press any required end-of-file key. - - You should see something print. Do not worry if the text - does not look right; we will fix that later. + + You should see something print. Do not worry if the + text does not look right; we will fix that later. - + Enabling the Spooler: The <filename>/etc/printcap</filename> File At this point, your printer should be hooked up, your kernel - configured to communicate with it (if necessary), and you have been - able to send some simple data to the printer. Now, we are ready to - configure LPD to control access to your printer. - + configured to communicate with it (if necessary), and you have + been able to send some simple data to the printer. Now, we are + ready to configure LPD to control access to your printer. + You configure LPD by editing the file - /etc/printcap. The LPD spooling system reads - this file each time the spooler is used, so updates to the file take - immediate effect. - - The format of the &man.printcap.5; file is straightforward. Use - your favorite text editor to make changes to + /etc/printcap. The LPD spooling system + reads this file each time the spooler is used, so updates to the + file take immediate effect. + + The format of the &man.printcap.5; file is straightforward. + Use your favorite text editor to make changes to /etc/printcap. The format is identical to other capability files like /usr/share/misc/termcap and - /etc/remote. For complete information about - the format, see the &man.cgetent.3;. - + /etc/remote. For complete information + about the format, see the &man.cgetent.3;. + The simple spooler configuration consists of the following steps: - Pick a name (and a few convenient aliases) for the printer, - and put them in the /etc/printcap file; see - Naming the - Printer. + Pick a name (and a few convenient aliases) for the + printer, and put them in the + /etc/printcap file; see the + Naming the Printer + section for more information on naming. - + - Turn off header pages (which are on by default) by inserting - the sh capability; see Suppressing Header - Pages. + Turn off header pages (which are on by default) by + inserting the sh capability; see the + Suppressing Header + Pages section for more information. - + - Make a spooling directory, and specify its location with the - sd capability; see Making the Spooling - Directory. + Make a spooling directory, and specify its location with + the sd capability; see the Making the Spooling + Directory section for more information. - + Set the /dev entry to use for the - printer, and note it in /etc/printcap with - the lp capability; see Identifying the Printer - Device. Also, if the printer is on a serial port, set - up the communication parameters with the fs, - fc, xs, and - xc capabilities; see Configuring Spooler - Communications Parameters. + printer, and note it in /etc/printcap + with the lp capability; see the Identifying the Printer + Device for more information. Also, if the printer is + on a serial port, set up the communication parameters with + the fs, fc, + xs, and xc + capabilities; which is discussed in the Configuring Spooler + Communications Parameters section. - + - Install a plain text input filter; see Installing the Text - Filter + Install a plain text input filter; see the Installing the Text + Filter section for details. - + Test the setup by printing something with the - &man.lpr.1; command; see Trying It Out and Troubleshooting. + &man.lpr.1; command. More details are available in the + Trying It Out and + Troubleshooting + sections. - Language-based printers, such as PostScript printers, cannot - directly print plain text. The simple setup outlined above and - described in the following sections assumes that if you are - installing such a printer you will print only files that the - printer can understand. + Language-based printers, such as PostScript printers, + cannot directly print plain text. The simple setup outlined + above and described in the following sections assumes that if + you are installing such a printer you will print only files + that the printer can understand. - Users often expect that they can print plain text to any of the - printers installed on your system. Programs that interface to LPD - to do their printing usually make the same assumption. If you are - installing such a printer and want to be able to print jobs in the - printer language and print plain text jobs, you - are strongly urged to add an additional step to the simple setup - outlined above: install an automatic plain-text-to-PostScript (or - other printer language) conversion program. Section Accommodating Plain Text - Jobs on PostScript Printers tells how to do this. - + Users often expect that they can print plain text to any of + the printers installed on your system. Programs that interface + to LPD to do their printing usually make the same assumption. + If you are installing such a printer and want to be able to + print jobs in the printer language and + print plain text jobs, you are strongly urged to add an + additional step to the simple setup outlined above: install an + automatic plain-text-to-PostScript (or other printer language) + conversion program. The section entitled Accommodating Plain + Text Jobs on PostScript Printers tells how to do + this. + Naming the Printer - - The first (easy) step is to pick a name for your printer. It - really does not matter whether you choose functional or whimsical - names since you can also provide a number aliases for the - printer. - + + The first (easy) step is to pick a name for your printer + It really does not matter whether you choose functional or + whimsical names since you can also provide a number aliases + for the printer. + At least one of the printers specified in the /etc/printcap should have the alias - lp. This is the default printer's name. If - users do not have the PRINTER environment variable - nor specify a printer name on the command line of any of the LPD - commands, then lp will be the default printer - they get to use. - + lp. This is the default printer's name. + If users do not have the PRINTER environment + variable nor specify a printer name on the command line of any + of the LPD commands, then lp will be the + default printer they get to use. + Also, it is common practice to make the last alias for a - printer be a full description of the printer, including make and - model. - - Once you have picked a name and some common aliases, put them - in the /etc/printcap file. The name of the - printer should start in the leftmost column. Separate each alias - with a vertical bar and put a colon after the last alias. - + printer be a full description of the printer, including make + and model. + + Once you have picked a name and some common aliases, put + them in the /etc/printcap file. The name + of the printer should start in the leftmost column. Separate + each alias with a vertical bar and put a colon after the last + alias. + In the following example, we start with a skeletal - /etc/printcap that defines two printers (a - Diablo 630 line printer and a Panasonic KX-P4455 PostScript laser - printer): + /etc/printcap that defines two printers + (a Diablo 630 line printer and a Panasonic KX-P4455 PostScript + laser printer): # # /etc/printcap for host rose # rattan|line|diablo|lp|Diablo 630 Line Printer: bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4: - + In this example, the first printer is named rattan and has as aliases line, diablo, lp, and Diablo 630 Line - Printer. Since it has the alias - lp, it is also the default printer. The second - is named bamboo, and has as aliases + Printer. Since it has the alias + lp, it is also the default printer. The + second is named bamboo, and has as aliases ps, PS, S, panasonic, and Panasonic KX-P4455 PostScript v51.4. Suppressing Header Pages - + The LPD spooling system will by default print a - header page for each job. The header page - contains the user name who requested the job, the host from which - the job came, and the name of the job, in nice large letters. - Unfortunately, all this extra text gets in the way of debugging - the simple printer setup, so we will suppress header pages. - + header page for each job. The header + page contains the user name who requested the job, the host + from which the job came, and the name of the job, in nice + large letters. Unfortunately, all this extra text gets in the + way of debugging the simple printer setup, so we will suppress + header pages. + To suppress header pages, add the sh capability to the entry for the printer in - /etc/printcap. Here is the example + /etc/printcap. Here is an example /etc/printcap with sh added: - + # # /etc/printcap for host rose - no header pages anywhere # rattan|line|diablo|lp|Diablo 630 Line Printer:\ :sh: bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4:\ :sh: - Note how we used the correct format: the first line starts in - the leftmost column, and subsequent lines are indented with a - single TAB. Every line in an entry except the last ends in a - backslash character. + Note how we used the correct format: the first line starts + in the leftmost column, and subsequent lines are indented with + a single TAB. Every line in an entry except the last ends in + a backslash character. Making the Spooling Directory - + The next step in the simple spooler setup is to make a - spooling directory, a directory where print - jobs reside until they are printed, and where a number of other - spooler support files live. - - Because of the variable nature of spooling directories, it is - customary to put these directories under - /var/spool. It is not necessary to backup - the contents of spooling directories, either. Recreating them is - as simple as running &man.mkdir.1;. - - It is also customary to make the directory with a name that is - identical to the name of the printer, as shown below: - + spooling directory, a directory where + print jobs reside until they are printed, and where a number + of other spooler support files live. + + Because of the variable nature of spooling directories, it + is customary to put these directories under + /var/spool. It is not necessary to + backup the contents of spooling directories, either. + Recreating them is as simple as running &man.mkdir.1;. + + It is also customary to make the directory with a name + that is identical to the name of the printer, as shown + below: + &prompt.root; mkdir /var/spool/printer-name - - However, if you have a lot of printers on your network, you - might want to put the spooling directories under a single - directory that you reserve just for printing with LPD. We will do - this for our two example printers rattan and + + However, if you have a lot of printers on your network, + you might want to put the spooling directories under a single + directory that you reserve just for printing with LPD. We + will do this for our two example printers + rattan and bamboo: - + &prompt.root; mkdir /var/spool/lpd &prompt.root; mkdir /var/spool/lpd/rattan &prompt.root; mkdir /var/spool/lpd/bamboo - + - If you are concerned about the privacy of jobs that users - print, you might want to protect the spooling directory so it is - not publicly accessible. Spooling directories should be owned - and be readable, writable, and searchable by user daemon and - group daemon, and no one else. We will do this for our example - printers: - + If you are concerned about the privacy of jobs that + users print, you might want to protect the spooling + directory so it is not publicly accessible. Spooling + directories should be owned and be readable, writable, and + searchable by user daemon and group daemon, and no one else. + We will do this for our example printers: + &prompt.root; chown daemon.daemon /var/spool/lpd/rattan &prompt.root; chown daemon.daemon /var/spool/lpd/bamboo &prompt.root; chmod 770 /var/spool/lpd/rattan &prompt.root; chmod 770 /var/spool/lpd/bamboo - - Finally, you need to tell LPD about these directories using - the /etc/printcap file. You specify the - pathname of the spooling directory with the sd - capability: + + Finally, you need to tell LPD about these directories + using the /etc/printcap file. You + specify the pathname of the spooling directory with the + sd capability: # # /etc/printcap for host rose - added spooling directories # rattan|line|diablo|lp|Diablo 630 Line Printer:\ :sh:sd=/var/spool/lpd/rattan: bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4:\ :sh:sd=/var/spool/lpd/bamboo: - Note that the name of the printer starts in the first column - but all other entries describing the printer should be indented - with a tab and each line escaped with a backslash. - + Note that the name of the printer starts in the first + column but all other entries describing the printer should be + indented with a tab and each line escaped with a + backslash. + If you do not specify a spooling directory with sd, the spooling system will use /var/spool/lpd as a default. - + Identifying the Printer Device - - In section Adding /dev - Entries for the Ports, we identified which entry in the + + In the Adding + /dev Entries for the Ports + section, we identified which entry in the /dev directory FreeBSD will use to - communicate with the printer. Now, we tell LPD that information. - When the spooling system has a job to print, it will open the - specified device on behalf of the filter program (which is - responsible for passing data to the printer). - + communicate with the printer. Now, we tell LPD that + information. When the spooling system has a job to print, it + will open the specified device on behalf of the filter program + (which is responsible for passing data to the printer). + List the /dev entry pathname in the /etc/printcap file using the lp capability. - + In our running example, let us assume that rattan is on the first parallel port, and - bamboo is on a sixth serial port; here are the - additions to /etc/printcap: - + bamboo is on a sixth serial port; here are + the additions to /etc/printcap: + # # /etc/printcap for host rose - identified what devices to use # rattan|line|diablo|lp|Diablo 630 Line Printer:\ :sh:sd=/var/spool/lpd/rattan:\ :lp=/dev/lpt0: bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4:\ :sh:sd=/var/spool/lpd/bamboo:\ :lp=/dev/ttyd5: - - If you do not specify the lp capability for - a printer in your /etc/printcap file, LPD - uses /dev/lp as a default. + + If you do not specify the lp capability + for a printer in your /etc/printcap file, + LPD uses /dev/lp as a default. /dev/lp currently does not exist in FreeBSD. - - If the printer you are installing is connected to a parallel - port, skip to the section Installing the Text Filter. - Otherwise, be sure to follow the instructions in the next - section. + + If the printer you are installing is connected to a + parallel port, skip to the section entitled, Installing the Text + Filter. Otherwise, be sure to follow the instructions + in the next section. - + Configuring Spooler Communication Parameters - + For printers on serial ports, LPD can set up the bps rate, - parity, and other serial communication parameters on behalf of the - filter program that sends data to the printer. This is + parity, and other serial communication parameters on behalf of + the filter program that sends data to the printer. This is advantageous since: - + It lets you try different communication parameters by - simply editing the /etc/printcap file; - you do not have to recompile the filter program. + simply editing the /etc/printcap + file; you do not have to recompile the filter + program. - + It enables the spooling system to use the same filter - program for multiple printers which may have different serial - communication settings. + program for multiple printers which may have different + serial communication settings. - The following /etc/printcap capabilities - control serial communication parameters of the device listed in - the lp capability: + The following /etc/printcap + capabilities control serial communication parameters of the + device listed in the lp capability: br#bps-rate Sets the communications speed of the device to bps-rate, where - bps-rate can be 50, 75, 110, 134, - 150, 200, 300, 600, 1200, 1800, 2400, 4800, 9600, 19200, or - 38400 bits-per-second. + bps-rate can be 50, 75, 110, + 134, 150, 200, 300, 600, 1200, 1800, 2400, 4800, 9600, + 19200, or 38400 bits-per-second. - + fc#clear-bits - + Clears the flag bits clear-bits in the - sgttyb structure after opening - the device. + sgttyb structure after + opening the device. - + fs#set-bits - + - Sets the flag bits set-bits - in the sgttyb structure. + Sets the flag bits + set-bits in the + sgttyb structure. - + xc#clear-bits - + Clears local mode bits clear-bits after opening the device. - + xs#set-bits - + Sets local mode bits set-bits. - + For more information on the bits for the fc, fs, - xc, and xs capabilities, see - the file + xc, and xs capabilities, + see the file /usr/include/sys/ioctl_compat.h. - + When LPD opens the device specified by the - lp capability, it reads the flag bits in the - sgttyb structure; it clears any bits in the - fc capability, then sets bits in the + lp capability, it reads the flag bits in + the sgttyb structure; it clears any bits in + the fc capability, then sets bits in the fs capability, then applies the resultant - setting. It does the same for the local mode bits as well. - - Let us add to our example printer on the sixth serial port. - We will set the bps rate to 38400. For the flag bits, we will set - the TANDEM, ANYP, LITOUT, FLUSHO, and PASS8 flags. For the local - mode bits, we will set the LITOUT and PASS8 flags: + setting. It does the same for the local mode bits as + well. + + Let us add to our example printer on the sixth serial + port. We will set the bps rate to 38400. For the flag bits, + we will set the TANDEM, + ANYP, LITOUT, + FLUSHO, and PASS8 flags. + For the local mode bits, we will set the + LITOUT and PASS8 + flags: bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4:\ :sh:sd=/var/spool/lpd/bamboo:\ :lp=/dev/ttyd5:fs#0x82000c1:xs#0x820: Installing the Text Filter - - We are now ready to tell LPD what text filter to use to send - jobs to the printer. A text filter, also - known as an input filter, is a program that - LPD runs when it has a job to print. When LPD runs the text - filter for a printer, it sets the filter's standard input to the - job to print, and its standard output to the printer device - specified with the lp capability. The filter - is expected to read the job from standard input, perform any - necessary translation for the printer, and write the results to - standard output, which will get printed. For more information on - the text filter, see section Filters. - - For our simple printer setup, the text filter can be a small - shell script that just executes /bin/cat to - send the job to the printer. FreeBSD comes with another filter - called lpf that handles backspacing and - underlining for printers that might not deal with such character - streams well. And, of course, you can use any other filter - program you want. The filter lpf is described - in detail in section lpf: a - Text Filter. - + + We are now ready to tell LPD what text filter to use to + send jobs to the printer. A text filter, + also known as an input filter, is a + program that LPD runs when it has a job to print. When LPD + runs the text filter for a printer, it sets the filter's + standard input to the job to print, and its standard output to + the printer device specified with the lp + capability. The filter is expected to read the job from + standard input, perform any necessary translation for the + printer, and write the results to standard output, which will + get printed. For more information on the text filter, see + the Filters + section. + + For our simple printer setup, the text filter can be a + small shell script that just executes + /bin/cat to send the job to the printer. + FreeBSD comes with another filter called + lpf that handles backspacing and + underlining for printers that might not deal with such + character streams well. And, of course, you can use any other + filter program you want. The filter lpf is + described in detail in section entitled lpf: a Text + Filter. + First, let us make the shell script - /usr/local/libexec/if-simple be a simple text - filter. Put the following text into that file with your favorite - text editor: - + /usr/local/libexec/if-simple be a simple + text filter. Put the following text into that file with your + favorite text editor: + #!/bin/sh # # if-simple - Simple text input filter for lpd # Installed in /usr/local/libexec/if-simple # # Simply copies stdin to stdout. Ignores all filter arguments. /bin/cat && exit 0 exit 2 - + Make the file executable: - + &prompt.root; chmod 555 /usr/local/libexec/if-simple - + And then tell LPD to use it by specifying it with the if capability in /etc/printcap. We will add it to the two printers we have so far in the example /etc/printcap: - + # # /etc/printcap for host rose - added text filter # rattan|line|diablo|lp|Diablo 630 Line Printer:\ :sh:sd=/var/spool/lpd/rattan:\ :lp=/dev/lpt0:\ :if=/usr/local/libexec/if-simple: bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4:\ :sh:sd=/var/spool/lpd/bamboo:\ :lp=/dev/ttyd5:fs#0x82000e1:xs#0x820:\ :if=/usr/local/libexec/if-simple: Trying It Out - + You have reached the end of the simple LPD setup. - Unfortunately, congratulations are not quite yet in order, since - we still have to test the setup and correct any problems. To test - the setup, try printing something. To print with the LPD system, - you use the command &man.lpr.1;, + Unfortunately, congratulations are not quite yet in order, + since we still have to test the setup and correct any + problems. To test the setup, try printing something. To + print with the LPD system, you use the command &man.lpr.1;, which submits a job for printing. - - You can combine &man.lpr.1; with the &man.lptest.1; program, - introduced in section Checking - Printer Communications to generate some test text. + + You can combine &man.lpr.1; with the &man.lptest.1; + program, introduced in section Checking Printer + Communications to generate some test text. To test the simple LPD setup: - + Type: - + &prompt.root; lptest 20 5 | lpr -Pprinter-name - Where printer-name is a the name of - a printer (or an alias) specified in - /etc/printcap. To test the default printer, - type &man.lpr.1; without any - argument. Again, if you are testing a printer - that expects PostScript, send a PostScript program in that - language instead of using &man.lptest.1;. You can do so by - putting the program in a file and typing lpr - file. - - For a PostScript printer, you should get the results of the - program. If you are using &man.lptest.1;, then your results - should look like the following: + Where printer-name is a the + name of a printer (or an alias) specified in + /etc/printcap. To test the default + printer, type &man.lpr.1; without any + argument. Again, if you are testing a printer that expects + PostScript, send a PostScript program in that language instead + of using &man.lptest.1;. You can do so by putting the program + in a file and typing lpr + file. + + For a PostScript printer, you should get the results of + the program. If you are using &man.lptest.1;, then your + results should look like the following: - + !"#$%&'()*+,-./01234 "#$%&'()*+,-./012345 #$%&'()*+,-./0123456 $%&'()*+,-./01234567 %&'()*+,-./012345678 - - To further test the printer, try downloading larger programs - (for language-based printers) or running &man.lptest.1; with - different arguments. For example, lptest 80 60 - will produce 60 lines of 80 characters each. - - If the printer did not work, see the next section, Troubleshooting. + + To further test the printer, try downloading larger + programs (for language-based printers) or running + &man.lptest.1; with different arguments. For example, + lptest 80 60 will produce 60 lines of 80 + characters each. + + If the printer did not work, see the Troubleshooting + section. + + + + + + Advanced Printer Setup + + This section describes filters for printing specially formatted + files, header pages, printing across networks, and restricting and + accounting for printer usage. - - Troubleshooting - - After performing the simple test with &man.lptest.1;, you - might have gotten one of the following results instead of the - correct printout: - - - - It worked, after awhile; or, it did not eject a full - sheet. - - - The printer printed the above, but it sat for awhile and - did nothing. In fact, you might have needed to press a - PRINT REMAINING or FORM FEED button on the printer to get - any results to appear. - - If this is the case, the printer was probably waiting to - see if there was any more data for your job before it - printed anything. To fix this problem, you can have the - text filter send a FORM FEED character (or whatever is - necessary) to the printer. This is usually sufficient to - have the printer immediately print any text remaining in its - internal buffer. It is also useful to make sure each print - job ends on a full sheet, so the next job does not start - somewhere on the middle of the last page of the previous - job. - - The following replacement for the shell script - /usr/local/libexec/if-simple prints a - form feed after it sends the job to the printer: + + Filters + + Although LPD handles network protocols, queuing, access control, + and other aspects of printing, most of the real + work happens in the filters. Filters are + programs that communicate with the printer and handle its device + dependencies and special requirements. In the simple printer setup, + we installed a plain text filter—an extremely simple one that + should work with most printers (section Installing the Text + Filter). + + However, in order to take advantage of format conversion, printer + accounting, specific printer quirks, and so on, you should understand + how filters work. It will ultimately be the filter's responsibility + to handle these aspects. And the bad news is that most of the time + you have to provide filters yourself. The good + news is that many are generally available; when they are not, they are + usually easy to write. + + Also, FreeBSD comes with one, + /usr/libexec/lpr/lpf, that works with many + printers that can print plain text. (It handles backspacing and tabs + in the file, and does accounting, but that is about all it does.) + There are also several filters and filter components in the FreeBSD + ports collection. + + Here is what you will find in this section: + + + + Section How Filters + Work, tries to give an overview of a filter's role in the + printing process. You should read this section to get an + understanding of what is happening “under the hood” + when LPD uses filters. This knowledge could help you anticipate + and debug problems you might encounter as you install more and + more filters on each of your printers. + + + + LPD expects every printer to be able to print plain text by + default. This presents a problem for PostScript (or other + language-based printers) which cannot directly print plain text. + Section Accommodating + Plain Text Jobs on PostScript Printers tells you what you + should do to overcome this problem. I recommend reading this + section if you have a PostScript printer. + + + + PostScript is a popular output format for many programs. Even + some people (myself included) write PostScript code directly. But + PostScript printers are expensive. Section Simulating PostScript on + Non-PostScript Printers tells how you can further modify + a printer's text filter to accept and print PostScript data on a + non-PostScript printer. I recommend reading + this section if you do not have a PostScript printer. + + + + Section Conversion + Filters tells about a way you can automate the conversion + of specific file formats, such as graphic or typesetting data, + into formats your printer can understand. After reading this + section, you should be able to set up your printers such that + users can type lpr -t to print troff data, or + lpr -d to print TeX DVI data, or lpr + -v to print raster image data, and so forth. I + recommend reading this section. + + + + Section Output + Filters tells all about a not often used feature of LPD: + output filters. Unless you are printing header pages (see Header Pages), + you can probably skip that section altogether. + + + + Section lpf: a Text + Filter describes lpf, a fairly + complete if simple text filter for line printers (and laser + printers that act like line printers) that comes with FreeBSD. If + you need a quick way to get printer accounting working for plain + text, or if you have a printer which emits smoke when it sees + backspace characters, you should definitely consider + lpf. + + + + + How Filters Work + + As mentioned before, a filter is an executable program started + by LPD to handle the device-dependent part of communicating with the + printer. + + When LPD wants to print a file in a job, it starts a filter + program. It sets the filter's standard input to the file to print, + its standard output to the printer, and its standard error to the + error logging file (specified in the lf + capability in /etc/printcap, or + /dev/console by default). + + Which filter LPD starts and the filter's arguments depend on + what is listed in the /etc/printcap file and + what arguments the user specified for the job on the + &man.lpr.1; command line. For example, if the user typed + lpr -t, LPD would start the troff filter, listed + in the tf capability for the destination printer. + If the user wanted to print plain text, it would start the + if filter (this is mostly true: see Output Filters for + details). + + There are three kinds of filters you can specify in + /etc/printcap: + + + + The text filter, confusingly called the + input filter in LPD documentation, handles + regular text printing. Think of it as the default filter. LPD + expects every printer to be able to print plain text by default, + and it is the text filter's job to make sure backspaces, tabs, + or other special characters do not confuse the printer. If you + are in an environment where you have to account for printer + usage, the text filter must also account for pages printed, + usually by counting the number of lines printed and comparing + that to the number of lines per page the printer supports. The + text filter is started with the following argument list: + + + filter-name + -c + -wwidth + -llength + -iindent + -n login + -h host + acct-file + + + where + + + + + + + appears if the job's submitted with lpr + -l + + + + + width + + + is the value from the pw (page + width) capability specified in + /etc/printcap, default 132 + + + + + length + + + is the value from the pl (page + length) capability, default 66 + + + + + indent + + + is the amount of the indentation from lpr + -i, default 0 + + + + + login + + + is the account name of the user printing the + file + + + + + host + + + is the host name from which the job was + submitted + + + + + acct-file + + + is the name of the accounting file from the + af capability. + + + + + + + + A conversion filter converts a specific + file format into one the printer can render onto paper. For + example, ditroff typesetting data cannot be directly printed, + but you can install a conversion filter for ditroff files to + convert the ditroff data into a form the printer can digest and + print. Section Conversion + Filters tells all about them. Conversion filters also + need to do accounting, if you need printer accounting. + Conversion filters are started with the following arguments: + + + filter-name + -xpixel-width + -ypixel-height + -n login + -h host + acct-file + + + where pixel-width is the value + from the px capability (default 0) and + pixel-height is the value from the + py capability (default 0). + + + + The output filter is used only if there + is no text filter, or if header pages are enabled. In my + experience, output filters are rarely used. Section Output Filters describe + them. There are only two arguments to an output filter: + + + filter-name + -wwidth + -llength + + + which are identical to the text filters and + arguments. + + + + Filters should also exit with the + following exit status: + + + + exit 0 + + + If the filter printed the file successfully. + + + + + exit 1 + + + If the filter failed to print the file but wants LPD to + try to print the file again. LPD will restart a filter if it + exits with this status. + + + + + exit 2 + + + If the filter failed to print the file and does not want + LPD to try again. LPD will throw out the file. + + + + + The text filter that comes with the FreeBSD release, + /usr/libexec/lpr/lpf, takes advantage of the + page width and length arguments to determine when to send a form + feed and how to account for printer usage. It uses the login, host, + and accounting file arguments to make the accounting entries. + + If you are shopping for filters, see if they are LPD-compatible. + If they are, they must support the argument lists described above. + If you plan on writing filters for general use, then have them + support the same argument lists and exit codes. + + + + Accommodating Plain Text Jobs on PostScript Printers + + If you are the only user of your computer and PostScript (or + other language-based) printer, and you promise to never send plain + text to your printer and to never use features of various programs + that will want to send plain text to your printer, then you do not + need to worry about this section at all. + + But, if you would like to send both PostScript and plain text + jobs to the printer, then you are urged to augment your printer + setup. To do so, we have the text filter detect if the arriving job + is plain text or PostScript. All PostScript jobs must start with + %! (for other printer languages, see your printer + documentation). If those are the first two characters in the job, + we have PostScript, and can pass the rest of the job directly. If + those are not the first two characters in the file, then the filter + will convert the text into PostScript and print the result. + + How do we do this? + + If you have got a serial printer, a great way to do it is to + install lprps. lprps is a + PostScript printer filter which performs two-way communication with + the printer. It updates the printer's status file with verbose + information from the printer, so users and administrators can see + exactly what the state of the printer is (such as toner + low or paper jam). But more + importantly, it includes a program called psif + which detects whether the incoming job is plain text and calls + textps (another program that comes with + lprps) to convert it to PostScript. It then uses + lprps to send the job to the printer. + + lprps is part of the FreeBSD ports collection + (see The Ports Collection). You can + fetch, build and install it yourself, of course. After installing + lprps, just specify the pathname to the + psif program that is part of + lprps. If you installed lprps + from the ports collection, use the following in the serial + PostScript printer's entry in + /etc/printcap: + + +:if=/usr/local/libexec/psif: - + You should also specify the rw capability; + that tells LPD to open the printer in read-write mode. + + If you have a parallel PostScript printer (and therefore cannot + use two-way communication with the printer, which + lprps needs), you can use the following shell + script as the text filter: + + #!/bin/sh # -# if-simple - Simple text input filter for lpd -# Installed in /usr/local/libexec/if-simple +# psif - Print PostScript or plain text on a PostScript printer +# Script version; NOT the version that comes with lprps +# Installed in /usr/local/libexec/psif # -# Simply copies stdin to stdout. Ignores all filter arguments. -# Writes a form feed character (\f) after printing job. -/bin/cat && printf "\f" && exit 0 -exit 2 - - - - - It produced the “staircase effect.” - - - You got the following on paper: - - -!"#$%&'()*+,-./01234 - "#$%&'()*+,-./012345 - #$%&'()*+,-./0123456 - - You have become another victim of the - staircase effect, caused by conflicting - interpretations of what characters should indicate a - new-line. UNIX-style operating systems use a single - character: ASCII code 10, the line feed (LF). MS-DOS, OS/2, - and others uses a pair of characters, ASCII code 10 - and ASCII code 13 (the carriage return - or CR). Many printers use the MS-DOS convention for - representing new-lines. - - When you print with FreeBSD, your text used just the - line feed character. The printer, upon seeing a line feed - character, advanced the paper one line, but maintained the - same horizontal position on the page for the next character - to print. That is what the carriage return is for: to move - the location of the next character to print to the left edge - of the paper. - - Here is what FreeBSD wants your printer to do: - - - - - - Printer received CR - Printer prints CR - - - - Printer received LF - Printer prints CR + LF - - - - - - Here are some ways to achieve this: +read first_line +first_two_chars=`expr "$first_line" : '\(..\)'` - - - Use the printer's configuration switches or control - panel to alter its interpretation of these characters. - Check your printer's manual to find out how to do - this. - - - If you boot your system into other operating - systems besides FreeBSD, you may have to - reconfigure the printer to use a - an interpretation for CR and LF characters that those - other operating systems use. You might prefer one of - the other solutions, below. - - - - - Have FreeBSD's serial line driver automatically - convert LF to CR+LF. Of course, this works with - printers on serial ports only. To - enable this feature, set the CRMOD bit in - fs capability in the - /etc/printcap file for the - printer. - - - - Send an escape code to the - printer to have it temporarily treat LF characters - differently. Consult your printer's manual for escape - codes that your printer might support. When you find - the proper escape code, modify the text filter to send - the code first, then send the print job. - - Here is an example text filter for printers that - understand the Hewlett-Packard PCL escape codes. This - filter makes the printer treat LF characters as a LF and - CR; then it sends the job; then it sends a form feed to - eject the last page of the job. It should work with - nearly all Hewlett Packard printers. - - +if [ "$first_two_chars" = "%!" ]; then + # + # PostScript job, print it. + # + echo "$first_line" && cat && printf "\004" && exit 0 + exit 2 +else + # + # Plain text, convert it, then print it. + # + ( echo "$first_line"; cat ) | /usr/local/bin/textps && printf "\004" && exit 0 + exit 2 +fi + + In the above script, textps is a program we + installed separately to convert plain text to PostScript. You can + use any text-to-PostScript program you wish. The FreeBSD ports + collection (see The Ports Collection) + includes a full featured text-to-PostScript program called + a2ps that you might want to investigate. + + + + Simulating PostScript on Non-PostScript Printers + + PostScript is the de facto standard for + high quality typesetting and printing. PostScript is, however, an + expensive standard. Thankfully, Alladin + Enterprises has a free PostScript work-alike called + Ghostscript that runs with FreeBSD. + Ghostscript can read most PostScript files and can render their + pages onto a variety of devices, including many brands of + non-PostScript printers. By installing Ghostscript and using a + special text filter for your printer, you can make your + non-PostScript printer act like a real PostScript printer. + + Ghostscript should be in the FreeBSD ports collection, if you + would like to install it from there. You can fetch, build, and + install it quite easily yourself, as well. + + To simulate PostScript, we have the text filter detect if it is + printing a PostScript file. If it is not, then the filter will pass + the file directly to the printer; otherwise, it will use Ghostscript + to first convert the file into a format the printer will + understand. + + Here is an example: the following script is a text filter + for Hewlett Packard DeskJet 500 printers. For other printers, + substitute the argument to the + gs (Ghostscript) command. (Type gs + -h to get a list of devices the current installation of + Ghostscript supports.) + + #!/bin/sh # -# hpif - Simple text input filter for lpd for HP-PCL based printers -# Installed in /usr/local/libexec/hpif +# ifhp - Print Ghostscript-simulated PostScript on a DeskJet 500 +# Installed in /usr/local/libexec/hpif + # -# Simply copies stdin to stdout. Ignores all filter arguments. -# Tells printer to treat LF as CR+LF. Ejects the page when done. +# Treat LF as CR+LF: +# +printf "\033&k2G" || exit 2 -printf "\033&k2G" && cat && printf "\033&l0H" && exit 0 -exit 2 - - Here is an example - /etc/printcap from a host called - orchid. It has a single printer attached to its first - parallel port, a Hewlett Packard LaserJet 3Si named - teak. It is using the above script as - its text filter: - - # -# /etc/printcap for host orchid +# Read first two characters of the file # -teak|hp|laserjet|Hewlett Packard LaserJet 3Si:\ - :lp=/dev/lpt0:sh:sd=/var/spool/lpd/teak:mx#0:\ - :if=/usr/local/libexec/hpif: - - - - - - - It overprinted each line. - - - The printer never advanced a line. All of the lines of - text were printed on top of each other on one line. - - This problem is the “opposite” of the - staircase effect, described above, and is much rarer. - Somewhere, the LF characters that FreeBSD uses to end a line - are being treated as CR characters to return the print - location to the left edge of the paper, but not also down a - line. - - Use the printer's configuration switches or control - panel to enforce the following interpretation of LF and CR - characters: - - - - - - Printer receives - Printer prints - - - - - - CR - CR - - - - LF - CR + LF - - - - - - - - The printer lost characters. - - - While printing, the printer did not print a few - characters in each line. The problem might have gotten - worse as the printer ran, losing more and more - characters. - - The problem is that the printer cannot keep up with the - speed at which the computer sends data over a serial line. - (This problem should not occur with printers on parallel - ports.) There are two ways to overcome the problem: +read first_line +first_two_chars=`expr "$first_line" : '\(..\)'` - - - If the printer supports XON/XOFF flow control, have - FreeBSD use it by specifying the TANDEM bit in the - fs capability. - - - - If the printer supports carrier flow control, - specify the MDMBUF bit in the fs - capability. Make sure the cable connecting the printer - to the computer is correctly wired for carrier flow - control. - - - - If the printer does not support any flow control, - use some combination of the NLDELAY, TBDELAY, CRDELAY, - VTDELAY, and BSDELAY bits in the fs - capability to add appropriate delays to the stream of - data sent to the printer. - - - - - - - It printed garbage. - - - The printer printed what appeared to be random garbage, - but not the desired text. - - This is usually another symptom of incorrect - communications parameters with a serial printer. - Double-check the bps rate in the br - capability, and the parity bits in the fs - and fc capabilities; make sure the - printer is using the same settings as specified in the - /etc/printcap file. - - - - - Nothing happened. - - - If nothing happened, the problem is probably within - FreeBSD and not the hardware. Add the log file - (lf) capability to the entry for the - printer you are debugging in the - /etc/printcap file. For example, here - is the entry for rattan, with the - lf capability: +if [ "$first_two_chars" = "%!" ]; then + # + # It is PostScript; use Ghostscript to scan-convert and print it. + # + # Note that PostScript files are actually interpreted programs, + # and those programs are allowed to write to stdout, which will + # mess up the printed output. So, we redirect stdout to stderr + # and then make descriptor 3 go to stdout, and have Ghostscript + # write its output there. Exercise for the clever reader: + # capture the stderr output from Ghostscript and mail it back to + # the user originating the print job. + # + exec 3>&1 1>&2 + /usr/local/bin/gs -dSAFER -dNOPAUSE -q -sDEVICE=djet500 \ + -sOutputFile=/dev/fd/3 - && exit 0 - + # + /usr/local/bin/gs -dSAFER -dNOPAUSE -q -sDEVICE=djet500 -sOutputFile=- - \ + && exit 0 +else + # + # Plain text or HP/PCL, so just print it directly; print a form + # at the end to eject the last page. + # + echo $first_line && cat && printf "\033&l0H" && +exit 0 +fi + +exit 2 + + Finally, you need to notify LPD of the filter via the + if capability: + + +:if=/usr/local/libexec/hpif: + + That is it. You can type lpr plain.text and + lpr whatever.ps and both should print + successfully. + + + + Conversion Filters + + After completing the simple setup described in Simple Printer Setup, the first + thing you will probably want to do is install conversion filters for + your favorite file formats (besides plain ASCII text). + + + Why Install Conversion Filters? + + Conversion filters make printing various kinds of files easy. + As an example, suppose we do a lot of work with the TeX + typesetting system, and we have a PostScript printer. Every time + we generate a DVI file from TeX, we cannot print it directly until + we convert the DVI file into PostScript. The command sequence + goes like this: + + &prompt.user; dvips seaweed-analysis.dvi +&prompt.user; lpr seaweed-analysis.ps + + By installing a conversion filter for DVI files, we can skip + the hand conversion step each time by having LPD do it for us. + Now, each time we get a DVI file, we are just one step away from + printing it: + + &prompt.user; lpr -d seaweed-analysis.dvi + + We got LPD to do the DVI file conversion for us by specifying + the option. Section Formatting and Conversion + Options lists the conversion options. + + For each of the conversion options you want a printer to + support, install a conversion filter and + specify its pathname in /etc/printcap. A + conversion filter is like the text filter for the simple printer + setup (see section Installing + the Text Filter) except that instead of printing plain + text, the filter converts the file into a format the printer can + understand. + + + + Which Conversions Filters Should I Install? + + You should install the conversion filters you expect to use. + If you print a lot of DVI data, then a DVI conversion filter is in + order. If you have got plenty of troff to print out, then you + probably want a troff filter. + + The following table summarizes the filters that LPD works + with, their capability entries for the + /etc/printcap file, and how to invoke them + with the lpr command: + + + + + + File type + /etc/printcap capability + lpr option + + + + + + cifplot + cf + + + + + DVI + df + + + + + plot + gf + + + + + ditroff + nf + + + + + FORTRAN text + rf + + + + + troff + rf + + + + + raster + vf + + + + + plain text + if + none, , or + + + + + + + In our example, using lpr -d means the + printer needs a df capability in its entry in + /etc/printcap. + + Despite what others might contend, formats like FORTRAN text + and plot are probably obsolete. At your site, you can give new + meanings to these or any of the formatting options just by + installing custom filters. For example, suppose you would like to + directly print Printerleaf files (files from the Interleaf desktop + publishing program), but will never print plot files. You could + install a Printerleaf conversion filter under the + gf capability and then educate your users that + lpr -g mean “print Printerleaf + files.” + + + + Installing Conversion Filters + + Since conversion filters are programs you install outside of + the base FreeBSD installation, they should probably go under + /usr/local. The directory + /usr/local/libexec is a popular location, + since they are specialized programs that only LPD will run; + regular users should not ever need to run them. + + To enable a conversion filter, specify its pathname under the + appropriate capability for the destination printer in + /etc/printcap. + + In our example, we will add the DVI conversion filter to the + entry for the printer named bamboo. Here is + the example /etc/printcap file again, with + the new df capability for the printer + bamboo. + + +# +# /etc/printcap for host rose - added df filter for bamboo +# rattan|line|diablo|lp|Diablo 630 Line Printer:\ :sh:sd=/var/spool/lpd/rattan:\ :lp=/dev/lpt0:\ - :if=/usr/local/libexec/if-simple:\ - :lf=/var/log/rattan.log - - Then, try printing again. Check the log file (in our - example, /var/log/rattan.log) to see - any error messages that might appear. Based on the messages - you see, try to correct the problem. - - If you do not specify a lf - capability, LPD uses /dev/console as a - default. - - - - - - - - - - Using Printers - - This section tells you how to use printers you have setup with - FreeBSD. Here is an overview of the user-level commands: + :if=/usr/local/libexec/if-simple: - - - &man.lpr.1; +bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4:\ + :sh:sd=/var/spool/lpd/bamboo:\ + :lp=/dev/ttyd5:fs#0x82000e1:xs#0x820:rw:\ + :if=/usr/local/libexec/psif:\ + :df=/usr/local/libexec/psdf: - - Print jobs - - - - - &man.lpq.1; + The DVI filter is a shell script named + /usr/local/libexec/psdf. Here is that + script: - - Check printer queues - - - - - &man.lprm.1; + +#!bin/sh +# +# psdf - DVI to PostScript printer filter +# Installed in /usr/local/libexec/psdf +# +# Invoked by lpd when user runs lpr -d +# +exec /usr/local/bin/dvips -f | /usr/local/libexec/lprps "$@" - - Remove jobs from a printer's queue - - - - - There is also an administrative command, &man.lpc.8;, described in - the section Administrating the LPD - Spooler, used to control printers and their queues. + This script runs dvips in filter mode (the + argument) on standard input, which is the job + to print. It then starts the PostScript printer filter + lprps (see section Accommodating Plain + Text Jobs on PostScript Printers) with the arguments LPD + passed to this script. lprps will use those + arguments to account for the pages printed. + + + + More Conversion Filter Examples + + Since there is no fixed set of steps to install conversion + filters, let me instead provide more examples. Use these as + guidance to making your own filters. Use them directly, if + appropriate. + + This example script is a raster (well, GIF file, actually) + conversion filter for a Hewlett Packard LaserJet III-Si + printer: + + +#!/bin/sh +# +# hpvf - Convert GIF files into HP/PCL, then print +# Installed in /usr/local/libexec/hpvf + +PATH=/usr/X11R6/bin:$PATH; export PATH +giftopnm | ppmtopgm | pgmtopbm | pbmtolj -resolution 300 \ + && exit 0 \ + || exit 2 - All three of the commands &man.lpr.1;, &man.lprm.1;, and &man.lpq.1; - accept an option to specify on which - printer/queue to operate, as listed in the - /etc/printcap file. This enables you to submit, - remove, and check on jobs for various printers. If you do not use the - option, then these commands use the printer - specified in the PRINTER environment variable. Finally, - if you do not have a PRINTER environment variable, these - commands default to the printer named lp. + It works by converting the GIF file into a portable anymap, + converting that into a portable graymap, converting that into a + portable bitmap, and converting that into LaserJet/PCL-compatible + data. + + Here is the /etc/printcap file with an + entry for a printer using the above filter: - Hereafter, the terminology default printer - means the printer named in the PRINTER environment - variable, or the printer named lp when there is no - PRINTER environment variable. - - - Printing Jobs - - To print files, type: - - &prompt.user; lpr filename ... - - This prints each of the listed files to the default printer. If - you list no files, &man.lpr.1; reads data to - print from standard input. For example, this command prints some - important system files: + +# +# /etc/printcap for host orchid +# +teak|hp|laserjet|Hewlett Packard LaserJet 3Si:\ + :lp=/dev/lpt0:sh:sd=/var/spool/lpd/teak:mx#0:\ + :if=/usr/local/libexec/hpif:\ + :vf=/usr/local/libexec/hpvf: + + The following script is a conversion filter for troff data + from the groff typesetting system for the PostScript printer named + bamboo: - &prompt.user; lpr /etc/host.conf /etc/hosts.equiv - - To select a specific printer, type: - - &prompt.user; lpr -P printer-name filename ... + +#!/bin/sh +# +# pstf - Convert groff's troff data into PS, then print. +# Installed in /usr/local/libexec/pstf +# +exec grops | /usr/local/libexec/lprps "$@" + + The above script makes use of lprps again + to handle the communication with the printer. If the printer were + on a parallel port, we would use this script instead: - This example prints a long listing of the current directory to the - printer named rattan: - - &prompt.user; ls -l | lpr -P rattan - - Because no files were listed for the - &man.lpr.1; command, lpr read the data to print - from standard input, which was the output of the ls - -l command. - - The &man.lpr.1; command can also accept a wide variety of options - to control formatting, apply file conversions, generate multiple - copies, and so forth. For more information, see the section Printing Options. - - - - Checking Jobs - - When you print with &man.lpr.1;, the data you wish to print is put - together in a package called a “print job”, which is sent - to the LPD spooling system. Each printer has a queue of jobs, and - your job waits in that queue along with other jobs from yourself and - from other users. The printer prints those jobs in a first-come, - first-served order. + +#!/bin/sh +# +# pstf - Convert groff's troff data into PS, then print. +# Installed in /usr/local/libexec/pstf +# +exec grops + + That is it. Here is the entry we need to add to + /etc/printcap to enable the filter: + + +:tf=/usr/local/libexec/pstf: + + Here is an example that might make old hands at FORTRAN blush. + It is a FORTRAN-text filter for any printer that can directly + print plain text. We will install it for the printer + teak: - To display the queue for the default printer, type &man.lpq.1;. - For a specific printer, use the option. For - example, the command + +#!/bin/sh +# +# hprf - FORTRAN text filter for LaserJet 3si: +# Installed in /usr/local/libexec/hprf +# - &prompt.user; lpq -P bamboo +printf "\033&k2G" && fpr && printf "\033&l0H" && + exit 0 +exit 2 + + And we will add this line to the + /etc/printcap for the printer + teak to enable this filter: + + +:rf=/usr/local/libexec/hprf: + + Here is one final, somewhat complex example. We will add a + DVI filter to the LaserJet printer teak + introduced earlier. First, the easy part: updating + /etc/printcap with the location of the DVI + filter: + + +:df=/usr/local/libexec/hpdf: + + Now, for the hard part: making the filter. For that, we need + a DVI-to-LaserJet/PCL conversion program. The FreeBSD ports + collection (see The Ports Collection) + has one: dvi2xx is the name of the package. + Installing this package gives us the program we need, + dvilj2p, which converts DVI into LaserJet IIp, + LaserJet III, and LaserJet 2000 compatible codes. + + dvilj2p makes the filter + hpdf quite complex since + dvilj2p cannot read from standard input. It + wants to work with a filename. What is worse, the filename has to + end in .dvi so using + /dev/fd/0 for standard input is problematic. + We can get around that problem by linking (symbolically) a + temporary file name (one that ends in .dvi) + to /dev/fd/0, thereby forcing + dvilj2p to read from standard input. + + The only other fly in the ointment is the fact that we cannot + use /tmp for the temporary link. Symbolic + links are owned by user and group bin. The + filter runs as user daemon. And the + /tmp directory has the sticky bit set. The + filter can create the link, but it will not be able clean up when + done and remove it since the link will belong to a different + user. + + Instead, the filter will make the symbolic link in the current + working directory, which is the spooling directory (specified by + the sd capability in + /etc/printcap). This is a perfect place for + filters to do their work, especially since there is (sometimes) + more free disk space in the spooling directory than under + /tmp. + + Here, finally, is the filter: + + +#!/bin/sh +# +# hpdf - Print DVI data on HP/PCL printer +# Installed in /usr/local/libexec/hpdf - shows the queue for the printer named bamboo. Here - is an example of the output of the lpq - command: - - bamboo is ready and printing -Rank Owner Job Files Total Size -active kelly 9 /etc/host.conf, /etc/hosts.equiv 88 bytes -2nd kelly 10 (standard input) 1635 bytes -3rd mary 11 ... 78519 bytes - - This shows three jobs in the queue for bamboo. - The first job, submitted by user kelly, got assigned “job - number” 9. Every job for a printer gets a unique job number. - Most of the time you can ignore the job number, but you will need it - if you want to cancel the job; see section Removing Jobs for details. - - Job number nine consists of two files; multiple files given on the - &man.lpr.1; command line are treated as part of a single job. It - is the currently active job (note the word active - under the “Rank” column), which means the printer should - be currently printing that job. The second job consists of data - passed as the standard input to the &man.lpr.1; command. The third - job came from user mary; it is a much larger - job. The pathname of the files she's trying to print is too long to - fit, so the &man.lpq.1; command just shows three dots. +PATH=/usr/local/bin:$PATH; export PATH - The very first line of the output from &man.lpq.1; is also useful: - it tells what the printer is currently doing (or at least what LPD - thinks the printer is doing). +# +# Define a function to clean up our temporary files. These exist +# in the current directory, which will be the spooling directory +# for the printer. +# +cleanup() { + rm -f hpdf$$.dvi +} - The &man.lpq.1; command also support a option - to generate a detailed long listing. Here is an example of - lpq -l: - - waiting for bamboo to become ready (offline ?) -kelly: 1st [job 009rose] - /etc/host.conf 73 bytes - /etc/hosts.equiv 15 bytes +# +# Define a function to handle fatal errors: print the given message +# and exit 2. Exiting with 2 tells LPD to do not try to reprint the +# job. +# +fatal() { + echo "$@" 1>&2 + cleanup + exit 2 +} -kelly: 2nd [job 010rose] - (standard input) 1635 bytes +# +# If user removes the job, LPD will send SIGINT, so trap SIGINT +# (and a few other signals) to clean up after ourselves. +# +trap cleanup 1 2 15 -mary: 3rd [job 011rose] - /home/orchid/mary/research/venus/alpha-regio/mapping 78519 bytes - +# +# Make sure we are not colliding with any existing files. +# +cleanup - - Removing Jobs - - If you change your mind about printing a job, you can remove the - job from the queue with the &man.lprm.1; command. Often, you can - even use &man.lprm.1; to remove an active job, but some or all of the - job might still get printed. - - To remove a job from the default printer, first use - &man.lpq.1; to find the job number. Then type: - - &prompt.user; lprm job-number - - To remove the job from a specific printer, add the - option. The following command removes job number - 10 from the queue for the printer bamboo: - - &prompt.user; lprm -P bamboo 10 - - The &man.lprm.1; command has a few shortcuts: - - - - lprm - +# +# Link the DVI input file to standard input (the file to print). +# +ln -s /dev/fd/0 hpdf$$.dvi || fatal "Cannot symlink /dev/fd/0" - - Removes all jobs (for the default printer) belonging to - you. - - +# +# Make LF = CR+LF +# +printf "\033&k2G" || fatal "Cannot initialize printer" - - lprm user - - - Removes all jobs (for the default printer) belonging to - user. The superuser can remove other - users' jobs; you can remove only your own jobs. - - +# +# Convert and print. Return value from dvilj2p does not seem to be +# reliable, so we ignore it. +# +dvilj2p -M1 -q -e- dfhp$$.dvi - - lprm - - - With no job number, user name, or - appearing on the command line, - &man.lprm.1; removes the currently active job on the - default printer, if it belongs to you. The superuser can remove - any active job. - - - +# +# Clean up and exit +# +cleanup +exit 0 + + + + Automated Conversion: An Alternative To Conversion + Filters + + All these conversion filters accomplish a lot for your + printing environment, but at the cost forcing the user to specify + (on the &man.lpr.1; command line) which one to use. + If your users are not particularly computer literate, having to + specify a filter option will become annoying. What is worse, + though, is that an incorrectly specified filter option may run a + filter on the wrong type of file and cause your printer to spew + out hundreds of sheets of paper. + + Rather than install conversion filters at all, you might want + to try having the text filter (since it is the default filter) + detect the type of file it has been asked to print and then + automatically run the right conversion filter. Tools such as + file can be of help here. Of course, it will + be hard to determine the differences between + some file types—and, of course, you can + still provide conversion filters just for them. + + The FreeBSD ports collection has a text filter that performs + automatic conversion called apsfilter. It can + detect plain text, PostScript, and DVI files, run the proper + conversions, and print. + + - Just use the option with the above shortcuts - to operate on a specific printer instead of the default. For example, - the following command removes all jobs for the current user in the - queue for the printer named rattan: - - &prompt.user; lprm -P rattan - - - - If you are working in a networked environment, &man.lprm.1; will - let you remove jobs only from the - host from which the jobs were submitted, even if the same printer is - available from other hosts. The following command sequence - demonstrates this: - - &prompt.user; lpr -P rattan myfile -&prompt.user; rlogin orchid -&prompt.user; lpq -P rattan -Rank Owner Job Files Total Size -active seeyan 12 ... 49123 bytes -2nd kelly 13 myfile 12 bytes -&prompt.user; lprm -P rattan 13 -rose: Permission denied -&prompt.user; logout -&prompt.user; lprm -P rattan 13 -dfA013rose dequeued -cfA013rose dequeued - - + + Output Filters + + The LPD spooling system supports one other type of filter that + we have not yet explored: an output filter. An output filter is + intended for printing plain text only, like the text filter, but + with many simplifications. If you are using an output filter but no + text filter, then: + + + + LPD starts an output filter once for the entire job instead + of once for each file in the job. + + + + LPD does not make any provision to identify the start or the + end of files within the job for the output filter. + + + + LPD does not pass the user's login or host to the filter, so + it is not intended to do accounting. In fact, it gets only two + arguments: + + + filter-name + -wwidth + -llength + + + Where width is from the + pw capability and + length is from the + pl capability for the printer in + question. + + + + Do not be seduced by an output filter's simplicity. If you + would like each file in a job to start on a different page an output + filter will not work. Use a text filter (also + known as an input filter); see section Installing the Text Filter. + Furthermore, an output filter is actually more + complex in that it has to examine the byte stream being + sent to it for special flag characters and must send signals to + itself on behalf of LPD. + + However, an output filter is necessary if + you want header pages and need to send escape sequences or other + initialization strings to be able to print the header page. (But it + is also futile if you want to charge header + pages to the requesting user's account, since LPD does not give any + user or host information to the output filter.) + + On a single printer, LPD allows both an output filter and text + or other filters. In such cases, LPD will start the output filter + to print the header page (see section Header Pages) + only. LPD then expects the output filter to stop + itself by sending two bytes to the filter: ASCII 031 + followed by ASCII 001. When an output filter sees these two bytes + (031, 001), it should stop by sending SIGSTOP to itself. When LPD's + done running other filters, it will restart the output filter by + sending SIGCONT to it. + + If there is an output filter but no text + filter and LPD is working on a plain text job, LPD uses the output + filter to do the job. As stated before, the output filter will + print each file of the job in sequence with no intervening form + feeds or other paper advancement, and this is probably + not what you want. In almost all cases, you + need a text filter. + + The program lpf, which we introduced earlier + as a text filter, can also run as an output filter. If you need a + quick-and-dirty output filter but do not want to write the byte + detection and signal sending code, try lpf. You + can also wrap lpf in a shell script to handle any + initialization codes the printer might require. + + + + <command>lpf</command>: a Text Filter + + The program /usr/libexec/lpr/lpf that comes + with FreeBSD binary distribution is a text filter (input filter) + that can indent output (job submitted with lpr + -i), allow literal characters to pass (job submitted + with lpr -l), adjust the printing position for + backspaces and tabs in the job, and account for pages printed. It + can also act like an output filter. + + lpf is suitable for many printing + environments. And although it has no capability to send + initialization sequences to a printer, it is easy to write a shell + script to do the needed initialization and then execute + lpf. + + In order for lpf to do page accounting + correctly, it needs correct values filled in for the + pw and pl capabilities in the + /etc/printcap file. It uses these values to + determine how much text can fit on a page and how many pages were in + a user's job. For more information on printer accounting, see Accounting for Printer + Usage. + - - Beyond Plain Text: Printing Options + + Header Pages - The &man.lpr.1; command supports a number of options that control - formatting text, converting graphic and other file formats, producing - multiple copies, handling of the job, and more. This section - describes the options. - - - Formatting and Conversion Options + If you have lots of users, all of them using + various printers, then you probably want to consider header + pages as a necessary evil. + + Header pages, also known as banner or + burst pages identify to whom jobs belong after + they are printed. They are usually printed in large, bold letters, + perhaps with decorative borders, so that in a stack of printouts they + stand out from the real documents that comprise users' jobs. They + enable users to locate their jobs quickly. The obvious drawback to a + header page is that it is yet one more sheet that has to be printed + for every job, their ephemeral usefulness lasting not more than a few + minutes, ultimately finding themselves in a recycling bin or rubbish + heap. (Note that header pages go with each job, not each file in a + job, so the paper waste might not be that bad.) + + The LPD system can provide header pages automatically for your + printouts if your printer can directly print + plain text. If you have a PostScript printer, you will need an + external program to generate the header page; see Header Pages on + PostScript Printers. + + + Enabling Header Pages - The following &man.lpr.1; options control formatting of the - files in the job. Use these options if the job does not contain - plain text or if you want plain text formatted through the - &man.pr.1; utility. - - For example, the following command prints a DVI file (from the - TeX typesetting system) named fish-report.dvi - to the printer named bamboo: - - &prompt.user; lpr -P bamboo -d fish-report.dvi - - These options apply to every file in the job, so you cannot mix - (say) DVI and ditroff files together in a job. Instead, submit the - files as separate jobs, using a different conversion option for each - job. + In the Simple Printer + Setup, we turned off header pages by specifying + sh (meaning “suppress header”) in the + /etc/printcap file. To enable header pages for + a printer, just remove the sh capability. - - All of these options except and - require conversion filters installed for the - destination printer. For example, the option - requires the DVI conversion filter. Section Conversion - Filters gives details. - + Sounds too easy, right? - - - + You are right. You might have to provide + an output filter to send initialization strings to the printer. + Here is an example output filter for Hewlett Packard PCL-compatible + printers: - - Print cifplot files. - - - - - - - - Print DVI files. - - - - - - - - Print FORTRAN text files. - - - - - - - - Print plot data. - - - - - - - - Indent the output by number - columns; if you omit number, indent - by 8 columns. This option works only with certain conversion - filters. - - - Do not put any space between the and - the number. - - - - - - - - - Print literal text data, including control - characters. - - - - - - - - Print ditroff (device independent troff) data. - - - - - -p - - - Format plain text with &man.pr.1; before printing. See - &man.pr.1; for more information. - - - - - - - - Use title on the - &man.pr.1; header instead of the file name. This option has - effect only when used with the - option. - - - - - - - - Print troff data. - - - - - - - - Print raster data. - - - - - Here is an example: this command prints a nicely formatted - version of the &man.ls.1; manual page on the default printer: - - &prompt.user; zcat /usr/share/man/man1/ls.1.gz | troff -t -man | lpr -t - - The &man.zcat.1; command uncompresses the source of the - - &man.ls.1; manual page and passes it to the &man.troff.1; - command, which formats that source and makes GNU troff output and - passes it to &man.lpr.1;, which submits the job to the LPD spooler. - Because we used the option to - - &man.lpr.1;, the spooler will convert the GNU troff output into - a format the default printer can understand when it prints the - job. - - - - Job Handling Options - - The following options to &man.lpr.1; tell LPD to handle the job - specially: - - - - -# copies - - - Produce a number of copies of - each file in the job instead of just one copy. An - administrator may disable this option to reduce printer - wear-and-tear and encourage photocopier usage. See section - Restricting - Multiple Copies. - - This example prints three copies of - parser.c followed by three copies of - parser.h to the default printer: - - &prompt.user; lpr -#3 parser.c parser.h - - - - - -m - - - Send mail after completing the print job. With this - option, the LPD system will send mail to your account when it - finishes handling your job. In its message, it will tell you - if the job completed successfully or if there was an error, - and (often) what the error was. - - - - - -s - - - Do not copy the files to the spooling directory, but make - symbolic links to them instead. - - If you are printing a large job, you probably want to use - this option. It saves space in the spooling directory (your - job might overflow the free space on the filesystem where the - spooling directory resides). It saves time as well since LPD - will not have to copy each and every byte of your job to the - spooling directory. - - There is a drawback, though: since LPD will refer to the - original files directly, you cannot modify or remove them - until they have been printed. - - - If you are printing to a remote printer, LPD will - eventually have to copy files from the local host to the - remote host, so the option will save - space only on the local spooling directory, not the remote. - It is still useful, though. - - - - - - -r - - - Remove the files in the job after copying them to the - spooling directory, or after printing them with the - option. Be careful with this - option! - - - - - - - Header Page Options - - These options to &man.lpr.1; adjust the text that normally - appears on a job's header page. If header pages are suppressed for - the destination printer, these options have no effect. See section - Header Pages - for information about setting up header pages. - - - - -C text - - - Replace the hostname on the header page with - text. The hostname is normally the - name of the host from which the job was submitted. - - - - - -J text - - - Replace the job name on the header page with - text. The job name is normally the - name of the first file of the job, or - stdin if you are printing standard - input. - - - - - -h - - - Do not print any header page. - - - At some sites, this option may have no effect due to the - way header pages are generated. See Header - Pages for details. - - - - - - - - - Administrating Printers - - As an administrator for your printers, you have had to install, - set up, and test them. Using the &man.lpc.8; command, you - can interact with your printers in yet more ways. With &man.lpc.8;, - you can - - - - Start and stop the printers - - - - Enable and disable their queues - - - - Rearrange the order of the jobs in each queue. - - - - First, a note about terminology: if a printer is - stopped, it will not print anything in its queue. - Users can still submit jobs, which will wait in the queue until the - printer is started or the queue is - cleared. - - If a queue is disabled, no user (except root) - can submit jobs for the printer. An enabled - queue allows jobs to be submitted. A printer can be - started for a disabled queue, in which case it - will continue to print jobs in the queue until the queue is - empty. - - In general, you have to have root privileges to use the - &man.lpc.8; command. Ordinary users can use the &man.lpc.8; command - to get printer status and to restart a hung printer only. - - Here is a summary of the &man.lpc.8; commands. Most of the - commands takes a printer-name argument to - tell on which printer to operate. You can use all - for the printer-name to mean all printers - listed in /etc/printcap. - - - - abort - printer-name - - - Cancel the current job and stop the printer. Users can - still submit jobs if the queue's enabled. - - - - - clean - printer-name - - - Remove old files from the printer's spooling directory. - Occasionally, the files that make up a job are not properly - removed by LPD, particularly if there have been errors during - printing or a lot of administrative activity. This command - finds files that do not belong in the spooling directory and - removes them. - - - - - disable - printer-name - - - Disable queuing of new jobs. If the printer's started, it - will continue to print any jobs remaining in the queue. The - superuser (root) can always submit jobs, even to a disabled - queue. - - This command is useful while you are testing a new printer - or filter installation: disable the queue and submit jobs as - root. Other users will not be able to submit jobs until you - complete your testing and re-enable the queue with the - enable command. - - - - - down printer-name - message - - - Take a printer down. Equivalent to - disable followed by stop. - The message appears as the printer's - status whenever a user checks the printer's queue with - &man.lpq.1; or status with lpc - status. - - - - - enable - printer-name - - - Enable the queue for a printer. Users can submit jobs but - the printer will not print anything until it is started. - - - - - help - command-name - - - Print help on the command - command-name. With no - command-name, print a summary of the - commands available. - - - - - restart - printer-name - - - Start the printer. Ordinary users can use this command if - some extraordinary circumstance hangs LPD, but they cannot start - a printer stopped with either the stop or - down commands. The - restart command is equivalent to - abort followed by - start. - - - - - start - printer-name - - - Start the printer. The printer will print jobs in its - queue. - - - - - stop - printer-name - - - Stop the printer. The printer will finish the current job - and will not print anything else in its queue. Even though the - printer is stopped, users can still submit jobs to an enabled - queue. - - - - - topq printer-name - job-or-username - - - Rearrange the queue for - printer-name by placing the jobs with - the listed job numbers or the jobs - belonging to username at the top of - the queue. For this command, you cannot use - all as the - printer-name. - - - - - up - printer-name - - - Bring a printer up; the opposite of the - down command. Equivalent to - start followed by - enable. - - - - - &man.lpc.8; accepts the above commands on the command line. If - you do not enter any commands, &man.lpc.8; enters an interactive mode, - where you can enter commands until you type exit, - quit, or end-of-file. - - - - - Advanced Printer Setup - - This section describes filters for printing specially formatted - files, header pages, printing across networks, and restricting and - accounting for printer usage. - - - Filters - - Although LPD handles network protocols, queuing, access control, - and other aspects of printing, most of the real - work happens in the filters. Filters are - programs that communicate with the printer and handle its device - dependencies and special requirements. In the simple printer setup, - we installed a plain text filter—an extremely simple one that - should work with most printers (section Installing the Text - Filter). - - However, in order to take advantage of format conversion, printer - accounting, specific printer quirks, and so on, you should understand - how filters work. It will ultimately be the filter's responsibility - to handle these aspects. And the bad news is that most of the time - you have to provide filters yourself. The good - news is that many are generally available; when they are not, they are - usually easy to write. - - Also, FreeBSD comes with one, - /usr/libexec/lpr/lpf, that works with many - printers that can print plain text. (It handles backspacing and tabs - in the file, and does accounting, but that is about all it does.) - There are also several filters and filter components in the FreeBSD - ports collection. - - Here is what you will find in this section: - - - - Section How Filters - Work, tries to give an overview of a filter's role in the - printing process. You should read this section to get an - understanding of what is happening “under the hood” - when LPD uses filters. This knowledge could help you anticipate - and debug problems you might encounter as you install more and - more filters on each of your printers. - - - - LPD expects every printer to be able to print plain text by - default. This presents a problem for PostScript (or other - language-based printers) which cannot directly print plain text. - Section Accommodating - Plain Text Jobs on PostScript Printers tells you what you - should do to overcome this problem. I recommend reading this - section if you have a PostScript printer. - - - - PostScript is a popular output format for many programs. Even - some people (myself included) write PostScript code directly. But - PostScript printers are expensive. Section Simulating PostScript on - Non-PostScript Printers tells how you can further modify - a printer's text filter to accept and print PostScript data on a - non-PostScript printer. I recommend reading - this section if you do not have a PostScript printer. - - - - Section Conversion - Filters tells about a way you can automate the conversion - of specific file formats, such as graphic or typesetting data, - into formats your printer can understand. After reading this - section, you should be able to set up your printers such that - users can type lpr -t to print troff data, or - lpr -d to print TeX DVI data, or lpr - -v to print raster image data, and so forth. I - recommend reading this section. - - - - Section Output - Filters tells all about a not often used feature of LPD: - output filters. Unless you are printing header pages (see Header Pages), - you can probably skip that section altogether. - - - - Section lpf: a Text - Filter describes lpf, a fairly - complete if simple text filter for line printers (and laser - printers that act like line printers) that comes with FreeBSD. If - you need a quick way to get printer accounting working for plain - text, or if you have a printer which emits smoke when it sees - backspace characters, you should definitely consider - lpf. - - - - - How Filters Work - - As mentioned before, a filter is an executable program started - by LPD to handle the device-dependent part of communicating with the - printer. - - When LPD wants to print a file in a job, it starts a filter - program. It sets the filter's standard input to the file to print, - its standard output to the printer, and its standard error to the - error logging file (specified in the lf - capability in /etc/printcap, or - /dev/console by default). - - Which filter LPD starts and the filter's arguments depend on - what is listed in the /etc/printcap file and - what arguments the user specified for the job on the - &man.lpr.1; command line. For example, if the user typed - lpr -t, LPD would start the troff filter, listed - in the tf capability for the destination printer. - If the user wanted to print plain text, it would start the - if filter (this is mostly true: see Output Filters for - details). - - There are three kinds of filters you can specify in - /etc/printcap: - - - - The text filter, confusingly called the - input filter in LPD documentation, handles - regular text printing. Think of it as the default filter. LPD - expects every printer to be able to print plain text by default, - and it is the text filter's job to make sure backspaces, tabs, - or other special characters do not confuse the printer. If you - are in an environment where you have to account for printer - usage, the text filter must also account for pages printed, - usually by counting the number of lines printed and comparing - that to the number of lines per page the printer supports. The - text filter is started with the following argument list: - - - filter-name - -c - -wwidth - -llength - -iindent - -n login - -h host - acct-file - - - where - - - - - - - appears if the job's submitted with lpr - -l - - - - - width - - - is the value from the pw (page - width) capability specified in - /etc/printcap, default 132 - - - - - length - - - is the value from the pl (page - length) capability, default 66 - - - - - indent - - - is the amount of the indentation from lpr - -i, default 0 - - - - - login - - - is the account name of the user printing the - file - - - - - host - - - is the host name from which the job was - submitted - - - - - acct-file - - - is the name of the accounting file from the - af capability. - - - - - - - - A conversion filter converts a specific - file format into one the printer can render onto paper. For - example, ditroff typesetting data cannot be directly printed, - but you can install a conversion filter for ditroff files to - convert the ditroff data into a form the printer can digest and - print. Section Conversion - Filters tells all about them. Conversion filters also - need to do accounting, if you need printer accounting. - Conversion filters are started with the following arguments: - - - filter-name - -xpixel-width - -ypixel-height - -n login - -h host - acct-file - - - where pixel-width is the value - from the px capability (default 0) and - pixel-height is the value from the - py capability (default 0). - - - - The output filter is used only if there - is no text filter, or if header pages are enabled. In my - experience, output filters are rarely used. Section Output Filters describe - them. There are only two arguments to an output filter: - - - filter-name - -wwidth - -llength - - - which are identical to the text filters and - arguments. - - - - Filters should also exit with the - following exit status: - - - - exit 0 - - - If the filter printed the file successfully. - - - - - exit 1 - - - If the filter failed to print the file but wants LPD to - try to print the file again. LPD will restart a filter if it - exits with this status. - - - - - exit 2 - - - If the filter failed to print the file and does not want - LPD to try again. LPD will throw out the file. - - - - - The text filter that comes with the FreeBSD release, - /usr/libexec/lpr/lpf, takes advantage of the - page width and length arguments to determine when to send a form - feed and how to account for printer usage. It uses the login, host, - and accounting file arguments to make the accounting entries. - - If you are shopping for filters, see if they are LPD-compatible. - If they are, they must support the argument lists described above. - If you plan on writing filters for general use, then have them - support the same argument lists and exit codes. - - - - Accommodating Plain Text Jobs on PostScript Printers - - If you are the only user of your computer and PostScript (or - other language-based) printer, and you promise to never send plain - text to your printer and to never use features of various programs - that will want to send plain text to your printer, then you do not - need to worry about this section at all. - - But, if you would like to send both PostScript and plain text - jobs to the printer, then you are urged to augment your printer - setup. To do so, we have the text filter detect if the arriving job - is plain text or PostScript. All PostScript jobs must start with - %! (for other printer languages, see your printer - documentation). If those are the first two characters in the job, - we have PostScript, and can pass the rest of the job directly. If - those are not the first two characters in the file, then the filter - will convert the text into PostScript and print the result. - - How do we do this? - - If you have got a serial printer, a great way to do it is to - install lprps. lprps is a - PostScript printer filter which performs two-way communication with - the printer. It updates the printer's status file with verbose - information from the printer, so users and administrators can see - exactly what the state of the printer is (such as toner - low or paper jam). But more - importantly, it includes a program called psif - which detects whether the incoming job is plain text and calls - textps (another program that comes with - lprps) to convert it to PostScript. It then uses - lprps to send the job to the printer. - - lprps is part of the FreeBSD ports collection - (see The Ports Collection). You can - fetch, build and install it yourself, of course. After installing - lprps, just specify the pathname to the - psif program that is part of - lprps. If you installed lprps - from the ports collection, use the following in the serial - PostScript printer's entry in - /etc/printcap: - - -:if=/usr/local/libexec/psif: - - You should also specify the rw capability; - that tells LPD to open the printer in read-write mode. - - If you have a parallel PostScript printer (and therefore cannot - use two-way communication with the printer, which - lprps needs), you can use the following shell - script as the text filter: - - -#!/bin/sh -# -# psif - Print PostScript or plain text on a PostScript printer -# Script version; NOT the version that comes with lprps -# Installed in /usr/local/libexec/psif -# - -read first_line -first_two_chars=`expr "$first_line" : '\(..\)'` - -if [ "$first_two_chars" = "%!" ]; then - # - # PostScript job, print it. - # - echo "$first_line" && cat && printf "\004" && exit 0 - exit 2 -else - # - # Plain text, convert it, then print it. - # - ( echo "$first_line"; cat ) | /usr/local/bin/textps && printf "\004" && exit 0 - exit 2 -fi - - In the above script, textps is a program we - installed separately to convert plain text to PostScript. You can - use any text-to-PostScript program you wish. The FreeBSD ports - collection (see The Ports Collection) - includes a full featured text-to-PostScript program called - a2ps that you might want to investigate. - - - - Simulating PostScript on Non-PostScript Printers - - PostScript is the de facto standard for - high quality typesetting and printing. PostScript is, however, an - expensive standard. Thankfully, Alladin - Enterprises has a free PostScript work-alike called - Ghostscript that runs with FreeBSD. - Ghostscript can read most PostScript files and can render their - pages onto a variety of devices, including many brands of - non-PostScript printers. By installing Ghostscript and using a - special text filter for your printer, you can make your - non-PostScript printer act like a real PostScript printer. - - Ghostscript should be in the FreeBSD ports collection, if you - would like to install it from there. You can fetch, build, and - install it quite easily yourself, as well. - - To simulate PostScript, we have the text filter detect if it is - printing a PostScript file. If it is not, then the filter will pass - the file directly to the printer; otherwise, it will use Ghostscript - to first convert the file into a format the printer will - understand. - - Here is an example: the following script is a text filter - for Hewlett Packard DeskJet 500 printers. For other printers, - substitute the argument to the - gs (Ghostscript) command. (Type gs - -h to get a list of devices the current installation of - Ghostscript supports.) - - -#!/bin/sh -# -# ifhp - Print Ghostscript-simulated PostScript on a DeskJet 500 -# Installed in /usr/local/libexec/hpif - -# -# Treat LF as CR+LF: -# -printf "\033&k2G" || exit 2 - -# -# Read first two characters of the file -# -read first_line -first_two_chars=`expr "$first_line" : '\(..\)'` - -if [ "$first_two_chars" = "%!" ]; then - # - # It is PostScript; use Ghostscript to scan-convert and print it. - # - # Note that PostScript files are actually interpreted programs, - # and those programs are allowed to write to stdout, which will - # mess up the printed output. So, we redirect stdout to stderr - # and then make descriptor 3 go to stdout, and have Ghostscript - # write its output there. Exercise for the clever reader: - # capture the stderr output from Ghostscript and mail it back to - # the user originating the print job. - # - exec 3>&1 1>&2 - /usr/local/bin/gs -dSAFER -dNOPAUSE -q -sDEVICE=djet500 \ - -sOutputFile=/dev/fd/3 - && exit 0 - - # - /usr/local/bin/gs -dSAFER -dNOPAUSE -q -sDEVICE=djet500 -sOutputFile=- - \ - && exit 0 -else - # - # Plain text or HP/PCL, so just print it directly; print a form - # at the end to eject the last page. - # - echo $first_line && cat && printf "\033&l0H" && exit 0 -fi - -exit 2 - - Finally, you need to notify LPD of the filter via the - if capability: - - -:if=/usr/local/libexec/hpif: - - That is it. You can type lpr plain.text and - lpr whatever.ps and both should print - successfully. - - - - Conversion Filters - - After completing the simple setup described in Simple Printer Setup, the first - thing you will probably want to do is install conversion filters for - your favorite file formats (besides plain ASCII text). - - - Why Install Conversion Filters? - - Conversion filters make printing various kinds of files easy. - As an example, suppose we do a lot of work with the TeX - typesetting system, and we have a PostScript printer. Every time - we generate a DVI file from TeX, we cannot print it directly until - we convert the DVI file into PostScript. The command sequence - goes like this: - - &prompt.user; dvips seaweed-analysis.dvi -&prompt.user; lpr seaweed-analysis.ps - - By installing a conversion filter for DVI files, we can skip - the hand conversion step each time by having LPD do it for us. - Now, each time we get a DVI file, we are just one step away from - printing it: - - &prompt.user; lpr -d seaweed-analysis.dvi - - We got LPD to do the DVI file conversion for us by specifying - the option. Section Formatting and Conversion - Options lists the conversion options. - - For each of the conversion options you want a printer to - support, install a conversion filter and - specify its pathname in /etc/printcap. A - conversion filter is like the text filter for the simple printer - setup (see section Installing - the Text Filter) except that instead of printing plain - text, the filter converts the file into a format the printer can - understand. - - - - Which Conversions Filters Should I Install? - - You should install the conversion filters you expect to use. - If you print a lot of DVI data, then a DVI conversion filter is in - order. If you have got plenty of troff to print out, then you - probably want a troff filter. - - The following table summarizes the filters that LPD works - with, their capability entries for the - /etc/printcap file, and how to invoke them - with the lpr command: - - - - - - File type - /etc/printcap capability - lpr option - - - - - - cifplot - cf - - - - - DVI - df - - - - - plot - gf - - - - - ditroff - nf - - - - - FORTRAN text - rf - - - - - troff - rf - - - - - raster - vf - - - - - plain text - if - none, , or - - - - - - - In our example, using lpr -d means the - printer needs a df capability in its entry in - /etc/printcap. - - Despite what others might contend, formats like FORTRAN text - and plot are probably obsolete. At your site, you can give new - meanings to these or any of the formatting options just by - installing custom filters. For example, suppose you would like to - directly print Printerleaf files (files from the Interleaf desktop - publishing program), but will never print plot files. You could - install a Printerleaf conversion filter under the - gf capability and then educate your users that - lpr -g mean “print Printerleaf - files.” - - - - Installing Conversion Filters - - Since conversion filters are programs you install outside of - the base FreeBSD installation, they should probably go under - /usr/local. The directory - /usr/local/libexec is a popular location, - since they are specialized programs that only LPD will run; - regular users should not ever need to run them. - - To enable a conversion filter, specify its pathname under the - appropriate capability for the destination printer in - /etc/printcap. - - In our example, we will add the DVI conversion filter to the - entry for the printer named bamboo. Here is - the example /etc/printcap file again, with - the new df capability for the printer - bamboo. - - -# -# /etc/printcap for host rose - added df filter for bamboo -# -rattan|line|diablo|lp|Diablo 630 Line Printer:\ - :sh:sd=/var/spool/lpd/rattan:\ - :lp=/dev/lpt0:\ - :if=/usr/local/libexec/if-simple: - -bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4:\ - :sh:sd=/var/spool/lpd/bamboo:\ - :lp=/dev/ttyd5:fs#0x82000e1:xs#0x820:rw:\ - :if=/usr/local/libexec/psif:\ - :df=/usr/local/libexec/psdf: - - The DVI filter is a shell script named - /usr/local/libexec/psdf. Here is that - script: - - -#!bin/sh -# -# psdf - DVI to PostScript printer filter -# Installed in /usr/local/libexec/psdf -# -# Invoked by lpd when user runs lpr -d -# -exec /usr/local/bin/dvips -f | /usr/local/libexec/lprps "$@" - - This script runs dvips in filter mode (the - argument) on standard input, which is the job - to print. It then starts the PostScript printer filter - lprps (see section Accommodating Plain - Text Jobs on PostScript Printers) with the arguments LPD - passed to this script. lprps will use those - arguments to account for the pages printed. - - - - More Conversion Filter Examples - - Since there is no fixed set of steps to install conversion - filters, let me instead provide more examples. Use these as - guidance to making your own filters. Use them directly, if - appropriate. - - This example script is a raster (well, GIF file, actually) - conversion filter for a Hewlett Packard LaserJet III-Si - printer: - - -#!/bin/sh -# -# hpvf - Convert GIF files into HP/PCL, then print -# Installed in /usr/local/libexec/hpvf - -PATH=/usr/X11R6/bin:$PATH; export PATH -giftopnm | ppmtopgm | pgmtopbm | pbmtolj -resolution 300 \ - && exit 0 \ - || exit 2 - - It works by converting the GIF file into a portable anymap, - converting that into a portable graymap, converting that into a - portable bitmap, and converting that into LaserJet/PCL-compatible - data. - - Here is the /etc/printcap file with an - entry for a printer using the above filter: - - -# -# /etc/printcap for host orchid -# -teak|hp|laserjet|Hewlett Packard LaserJet 3Si:\ - :lp=/dev/lpt0:sh:sd=/var/spool/lpd/teak:mx#0:\ - :if=/usr/local/libexec/hpif:\ - :vf=/usr/local/libexec/hpvf: - - The following script is a conversion filter for troff data - from the groff typesetting system for the PostScript printer named - bamboo: - - -#!/bin/sh -# -# pstf - Convert groff's troff data into PS, then print. -# Installed in /usr/local/libexec/pstf -# -exec grops | /usr/local/libexec/lprps "$@" - - The above script makes use of lprps again - to handle the communication with the printer. If the printer were - on a parallel port, we would use this script instead: - - -#!/bin/sh -# -# pstf - Convert groff's troff data into PS, then print. -# Installed in /usr/local/libexec/pstf -# -exec grops - - That is it. Here is the entry we need to add to - /etc/printcap to enable the filter: - - -:tf=/usr/local/libexec/pstf: - - Here is an example that might make old hands at FORTRAN blush. - It is a FORTRAN-text filter for any printer that can directly - print plain text. We will install it for the printer - teak: - - -#!/bin/sh -# -# hprf - FORTRAN text filter for LaserJet 3si: -# Installed in /usr/local/libexec/hprf -# - -printf "\033&k2G" && fpr && printf "\033&l0H" && exit 0 -exit 2 - - And we will add this line to the - /etc/printcap for the printer - teak to enable this filter: - - -:rf=/usr/local/libexec/hprf: - - Here is one final, somewhat complex example. We will add a - DVI filter to the LaserJet printer teak - introduced earlier. First, the easy part: updating - /etc/printcap with the location of the DVI - filter: - - -:df=/usr/local/libexec/hpdf: - - Now, for the hard part: making the filter. For that, we need - a DVI-to-LaserJet/PCL conversion program. The FreeBSD ports - collection (see The Ports Collection) - has one: dvi2xx is the name of the package. - Installing this package gives us the program we need, - dvilj2p, which converts DVI into LaserJet IIp, - LaserJet III, and LaserJet 2000 compatible codes. - - dvilj2p makes the filter - hpdf quite complex since - dvilj2p cannot read from standard input. It - wants to work with a filename. What is worse, the filename has to - end in .dvi so using - /dev/fd/0 for standard input is problematic. - We can get around that problem by linking (symbolically) a - temporary file name (one that ends in .dvi) - to /dev/fd/0, thereby forcing - dvilj2p to read from standard input. - - The only other fly in the ointment is the fact that we cannot - use /tmp for the temporary link. Symbolic - links are owned by user and group bin. The - filter runs as user daemon. And the - /tmp directory has the sticky bit set. The - filter can create the link, but it will not be able clean up when - done and remove it since the link will belong to a different - user. - - Instead, the filter will make the symbolic link in the current - working directory, which is the spooling directory (specified by - the sd capability in - /etc/printcap). This is a perfect place for - filters to do their work, especially since there is (sometimes) - more free disk space in the spooling directory than under - /tmp. - - Here, finally, is the filter: - - -#!/bin/sh -# -# hpdf - Print DVI data on HP/PCL printer -# Installed in /usr/local/libexec/hpdf - -PATH=/usr/local/bin:$PATH; export PATH - -# -# Define a function to clean up our temporary files. These exist -# in the current directory, which will be the spooling directory -# for the printer. -# -cleanup() { - rm -f hpdf$$.dvi -} - -# -# Define a function to handle fatal errors: print the given message -# and exit 2. Exiting with 2 tells LPD to do not try to reprint the -# job. -# -fatal() { - echo "$@" 1>&2 - cleanup - exit 2 -} - -# -# If user removes the job, LPD will send SIGINT, so trap SIGINT -# (and a few other signals) to clean up after ourselves. -# -trap cleanup 1 2 15 - -# -# Make sure we are not colliding with any existing files. -# -cleanup - -# -# Link the DVI input file to standard input (the file to print). -# -ln -s /dev/fd/0 hpdf$$.dvi || fatal "Cannot symlink /dev/fd/0" - -# -# Make LF = CR+LF -# -printf "\033&k2G" || fatal "Cannot initialize printer" - -# -# Convert and print. Return value from dvilj2p does not seem to be -# reliable, so we ignore it. -# -dvilj2p -M1 -q -e- dfhp$$.dvi - -# -# Clean up and exit -# -cleanup -exit 0 - - - - Automated Conversion: An Alternative To Conversion - Filters - - All these conversion filters accomplish a lot for your - printing environment, but at the cost forcing the user to specify - (on the &man.lpr.1; command line) which one to use. - If your users are not particularly computer literate, having to - specify a filter option will become annoying. What is worse, - though, is that an incorrectly specified filter option may run a - filter on the wrong type of file and cause your printer to spew - out hundreds of sheets of paper. - - Rather than install conversion filters at all, you might want - to try having the text filter (since it is the default filter) - detect the type of file it has been asked to print and then - automatically run the right conversion filter. Tools such as - file can be of help here. Of course, it will - be hard to determine the differences between - some file types—and, of course, you can - still provide conversion filters just for them. - - The FreeBSD ports collection has a text filter that performs - automatic conversion called apsfilter. It can - detect plain text, PostScript, and DVI files, run the proper - conversions, and print. - - - - - Output Filters - - The LPD spooling system supports one other type of filter that - we have not yet explored: an output filter. An output filter is - intended for printing plain text only, like the text filter, but - with many simplifications. If you are using an output filter but no - text filter, then: - - - - LPD starts an output filter once for the entire job instead - of once for each file in the job. - - - - LPD does not make any provision to identify the start or the - end of files within the job for the output filter. - - - - LPD does not pass the user's login or host to the filter, so - it is not intended to do accounting. In fact, it gets only two - arguments: - - - filter-name - -wwidth - -llength - - - Where width is from the - pw capability and - length is from the - pl capability for the printer in - question. - - - - Do not be seduced by an output filter's simplicity. If you - would like each file in a job to start on a different page an output - filter will not work. Use a text filter (also - known as an input filter); see section Installing the Text Filter. - Furthermore, an output filter is actually more - complex in that it has to examine the byte stream being - sent to it for special flag characters and must send signals to - itself on behalf of LPD. - - However, an output filter is necessary if - you want header pages and need to send escape sequences or other - initialization strings to be able to print the header page. (But it - is also futile if you want to charge header - pages to the requesting user's account, since LPD does not give any - user or host information to the output filter.) - - On a single printer, LPD allows both an output filter and text - or other filters. In such cases, LPD will start the output filter - to print the header page (see section Header Pages) - only. LPD then expects the output filter to stop - itself by sending two bytes to the filter: ASCII 031 - followed by ASCII 001. When an output filter sees these two bytes - (031, 001), it should stop by sending SIGSTOP to itself. When LPD's - done running other filters, it will restart the output filter by - sending SIGCONT to it. - - If there is an output filter but no text - filter and LPD is working on a plain text job, LPD uses the output - filter to do the job. As stated before, the output filter will - print each file of the job in sequence with no intervening form - feeds or other paper advancement, and this is probably - not what you want. In almost all cases, you - need a text filter. - - The program lpf, which we introduced earlier - as a text filter, can also run as an output filter. If you need a - quick-and-dirty output filter but do not want to write the byte - detection and signal sending code, try lpf. You - can also wrap lpf in a shell script to handle any - initialization codes the printer might require. - - - - <command>lpf</command>: a Text Filter - - The program /usr/libexec/lpr/lpf that comes - with FreeBSD binary distribution is a text filter (input filter) - that can indent output (job submitted with lpr - -i), allow literal characters to pass (job submitted - with lpr -l), adjust the printing position for - backspaces and tabs in the job, and account for pages printed. It - can also act like an output filter. - - lpf is suitable for many printing - environments. And although it has no capability to send - initialization sequences to a printer, it is easy to write a shell - script to do the needed initialization and then execute - lpf. - - In order for lpf to do page accounting - correctly, it needs correct values filled in for the - pw and pl capabilities in the - /etc/printcap file. It uses these values to - determine how much text can fit on a page and how many pages were in - a user's job. For more information on printer accounting, see Accounting for Printer - Usage. - - - - - Header Pages - - If you have lots of users, all of them using - various printers, then you probably want to consider header - pages as a necessary evil. - - Header pages, also known as banner or - burst pages identify to whom jobs belong after - they are printed. They are usually printed in large, bold letters, - perhaps with decorative borders, so that in a stack of printouts they - stand out from the real documents that comprise users' jobs. They - enable users to locate their jobs quickly. The obvious drawback to a - header page is that it is yet one more sheet that has to be printed - for every job, their ephemeral usefulness lasting not more than a few - minutes, ultimately finding themselves in a recycling bin or rubbish - heap. (Note that header pages go with each job, not each file in a - job, so the paper waste might not be that bad.) - - The LPD system can provide header pages automatically for your - printouts if your printer can directly print - plain text. If you have a PostScript printer, you will need an - external program to generate the header page; see Header Pages on - PostScript Printers. - - - Enabling Header Pages - - In the Simple Printer - Setup, we turned off header pages by specifying - sh (meaning “suppress header”) in the - /etc/printcap file. To enable header pages for - a printer, just remove the sh capability. - - Sounds too easy, right? - - You are right. You might have to provide - an output filter to send initialization strings to the printer. - Here is an example output filter for Hewlett Packard PCL-compatible - printers: - - + #!/bin/sh # # hpof - Output filter for Hewlett Packard PCL-compatible printers # Installed in /usr/local/libexec/hpof printf "\033&k2G" || exit 2 exec /usr/libexec/lpr/lpf - - Specify the path to the output filter in the - of capability. See Output Filters for more - information. - - Here is an example /etc/printcap file for - the printer teak that we introduced earlier; we - enabled header pages and added the above output filter: - - + + Specify the path to the output filter in the + of capability. See Output Filters for more + information. + + Here is an example /etc/printcap file for + the printer teak that we introduced earlier; we + enabled header pages and added the above output filter: + + # # /etc/printcap for host orchid # teak|hp|laserjet|Hewlett Packard LaserJet 3Si:\ :lp=/dev/lpt0:sd=/var/spool/lpd/teak:mx#0:\ :if=/usr/local/libexec/hpif:\ :vf=/usr/local/libexec/hpvf:\ :of=/usr/local/libexec/hpof: - - Now, when users print jobs to teak, they get - a header page with each job. If users want to spend time searching - for their printouts, they can suppress header pages by submitting - the job with lpr -h; see Header Page Options for - more &man.lpr.1; options. - - - LPD prints a form feed character after the header page. If - your printer uses a different character or sequence of characters - to eject a page, specify them with the ff - capability in /etc/printcap. - + + Now, when users print jobs to teak, they get + a header page with each job. If users want to spend time searching + for their printouts, they can suppress header pages by submitting + the job with lpr -h; see Header Page Options for + more &man.lpr.1; options. + + + LPD prints a form feed character after the header page. If + your printer uses a different character or sequence of characters + to eject a page, specify them with the ff + capability in /etc/printcap. + - Controlling Header Pages - - By enabling header pages, LPD will produce a long - header, a full page of large letters identifying the - user, host, and job. Here is an example (kelly printed the job - named outline from host rose): - - + Controlling Header Pages + + By enabling header pages, LPD will produce a long + header, a full page of large letters identifying the + user, host, and job. Here is an example (kelly printed the job + named outline from host rose): + + k ll ll k l l k l l k k eeee l l y y k k e e l l y y k k eeeeee l l y y kk k e l l y y k k e e l l y yy k k eeee lll lll yyy y y y y yyyy ll t l i t l oooo u u ttttt l ii n nnn eeee o o u u t l i nn n e e o o u u t l i n n eeeeee o o u u t l i n n e o o u uu t t l i n n e e oooo uuu u tt lll iii n n eeee r rrr oooo ssss eeee rr r o o s s e e r o o ss eeeeee r o o ss e r o o s s e e r oooo ssss eeee Job: outline Date: Sun Sep 17 11:04:58 1995 - LPD appends a form feed after this text so the job starts on a - new page (unless you have sf (suppress form - feeds) in the destination printer's entry in - /etc/printcap). - - If you prefer, LPD can make a short header; - specify sb (short banner) in the - /etc/printcap file. The header page will look - like this: - - + LPD appends a form feed after this text so the job starts on a + new page (unless you have sf (suppress form + feeds) in the destination printer's entry in + /etc/printcap). + + If you prefer, LPD can make a short header; + specify sb (short banner) in the + /etc/printcap file. The header page will look + like this: + + rose:kelly Job: outline Date: Sun Sep 17 11:07:51 1995 - Also by default, LPD prints the header page first, then the job. - To reverse that, specify hl (header last) in - /etc/printcap. + Also by default, LPD prints the header page first, then the job. + To reverse that, specify hl (header last) in + /etc/printcap. - Accounting for Header Pages - - Using LPD's built-in header pages enforces a particular paradigm - when it comes to printer accounting: header pages must be - free of charge. - - Why? - - Because the output filter is the only external program that will - have control when the header page is printed that could do - accounting, and it is not provided with any user or - host information or an accounting file, so it has no - idea whom to charge for printer use. It is also not enough to just - “add one page” to the text filter or any of the - conversion filters (which do have user and host information) since - users can suppress header pages with lpr -h. - They could still be charged for header pages they did not print. - Basically, lpr -h will be the preferred option of - environmentally-minded users, but you cannot offer any incentive to - use it. - - It is still not enough to have each of the - filters generate their own header pages (thereby being able to - charge for them). If users wanted the option of suppressing the - header pages with lpr -h, they will still get - them and be charged for them since LPD does not pass any knowledge - of the option to any of the filters. - - So, what are your options? - - You can: - - - - Accept LPD's paradigm and make header pages free. - - - - Install an alternative to LPD, such as LPRng or PLP. Section - Alternatives to the - Standard Spooler tells more about other spooling - software you can substitute for LPD. - - - - Write a smart output filter. Normally, - an output filter is not meant to do anything more than - initialize a printer or do some simple character conversion. It - is suited for header pages and plain text jobs (when there is no - text (input) filter). But, if there is a text filter for the - plain text jobs, then LPD will start the output filter only for - the header pages. And the output filter can parse the header - page text that LPD generates to determine what user and host to - charge for the header page. The only other problem with this - method is that the output filter still does not know what - accounting file to use (it is not passed the name of the file - from the af capability), but if you have a - well-known accounting file, you can hard-code that into the - output filter. To facilitate the parsing step, use the - sh (short header) capability in - /etc/printcap. Then again, all that might - be too much trouble, and users will certainly appreciate the - more generous system administrator who makes header pages - free. - - + Accounting for Header Pages + + Using LPD's built-in header pages enforces a particular paradigm + when it comes to printer accounting: header pages must be + free of charge. + + Why? + + Because the output filter is the only external program that will + have control when the header page is printed that could do + accounting, and it is not provided with any user or + host information or an accounting file, so it has no + idea whom to charge for printer use. It is also not enough to just + “add one page” to the text filter or any of the + conversion filters (which do have user and host information) since + users can suppress header pages with lpr -h. + They could still be charged for header pages they did not print. + Basically, lpr -h will be the preferred option of + environmentally-minded users, but you cannot offer any incentive to + use it. + + It is still not enough to have each of the + filters generate their own header pages (thereby being able to + charge for them). If users wanted the option of suppressing the + header pages with lpr -h, they will still get + them and be charged for them since LPD does not pass any knowledge + of the option to any of the filters. + + So, what are your options? + + You can: + + + + Accept LPD's paradigm and make header pages free. + + + + Install an alternative to LPD, such as LPRng or PLP. Section + Alternatives to the + Standard Spooler tells more about other spooling + software you can substitute for LPD. + + + + Write a smart output filter. Normally, + an output filter is not meant to do anything more than + initialize a printer or do some simple character conversion. It + is suited for header pages and plain text jobs (when there is no + text (input) filter). But, if there is a text filter for the + plain text jobs, then LPD will start the output filter only for + the header pages. And the output filter can parse the header + page text that LPD generates to determine what user and host to + charge for the header page. The only other problem with this + method is that the output filter still does not know what + accounting file to use (it is not passed the name of the file + from the af capability), but if you have a + well-known accounting file, you can hard-code that into the + output filter. To facilitate the parsing step, use the + sh (short header) capability in + /etc/printcap. Then again, all that might + be too much trouble, and users will certainly appreciate the + more generous system administrator who makes header pages + free. + + - Header Pages on PostScript Printers - - As described above, LPD can generate a plain text header page - suitable for many printers. Of course, PostScript cannot directly - print plain text, so the header page feature of LPD is - useless—or mostly so. - - One obvious way to get header pages is to have every conversion - filter and the text filter generate the header page. The filters - should should use the user and host arguments to generate a suitable - header page. The drawback of this method is that users will always - get a header page, even if they submit jobs with lpr - -h. - - Let us explore this method. The following script takes three - arguments (user login name, host name, and job name) and makes a - simple PostScript header page: - - + Header Pages on PostScript Printers + + As described above, LPD can generate a plain text header page + suitable for many printers. Of course, PostScript cannot directly + print plain text, so the header page feature of LPD is + useless—or mostly so. + + One obvious way to get header pages is to have every conversion + filter and the text filter generate the header page. The filters + should should use the user and host arguments to generate a suitable + header page. The drawback of this method is that users will always + get a header page, even if they submit jobs with lpr + -h. + + Let us explore this method. The following script takes three + arguments (user login name, host name, and job name) and makes a + simple PostScript header page: + + #!/bin/sh # # make-ps-header - make a PostScript header page on stdout # Installed in /usr/local/libexec/make-ps-header # # # These are PostScript units (72 to the inch). Modify for A4 or # whatever size paper you are using: # page_width=612 page_height=792 border=72 # # Check arguments # if [ $# -ne 3 ]; then echo "Usage: `basename $0` <user> <host> <job>" 1>&2 exit 1 fi # # Save these, mostly for readability in the PostScript, below. # user=$1 host=$2 job=$3 date=`date` # # Send the PostScript code to stdout. # exec cat <<EOF %!PS % % Make sure we do not interfere with user's job that will follow % save % % Make a thick, unpleasant border around the edge of the paper. % $border $border moveto $page_width $border 2 mul sub 0 rlineto 0 $page_height $border 2 mul sub rlineto currentscreen 3 -1 roll pop 100 3 1 roll setscreen $border 2 mul $page_width sub 0 rlineto closepath 0.8 setgray 10 setlinewidth stroke 0 setgray % % Display user's login name, nice and large and prominent % /Helvetica-Bold findfont 64 scalefont setfont $page_width ($user) stringwidth pop sub 2 div $page_height 200 sub moveto ($user) show % % Now show the boring particulars % /Helvetica findfont 14 scalefont setfont /y 200 def [ (Job:) (Host:) (Date:) ] { 200 y moveto show /y y 18 sub def } forall /Helvetica-Bold findfont 14 scalefont setfont /y 200 def [ ($job) ($host) ($date) ] { 270 y moveto show /y y 18 sub def } forall % % That is it % restore showpage EOF - Now, each of the conversion filters and the text filter can call - this script to first generate the header page, and then print the - user's job. Here is the DVI conversion filter from earlier in this - document, modified to make a header page: + Now, each of the conversion filters and the text filter can call + this script to first generate the header page, and then print the + user's job. Here is the DVI conversion filter from earlier in this + document, modified to make a header page: - + #!/bin/sh # # psdf - DVI to PostScript printer filter # Installed in /usr/local/libexec/psdf # # Invoked by lpd when user runs lpr -d # - + orig_args="$@" fail() { echo "$@" 1>&2 exit 2 } while getopts "x:y:n:h:" option; do case $option in x|y) ;; # Ignore n) login=$OPTARG ;; h) host=$OPTARG ;; *) echo "LPD started `basename $0` wrong." 1>&2 exit 2 ;; esac done [ "$login" ] || fail "No login name" [ "$host" ] || fail "No host name" ( /usr/local/libexec/make-ps-header $login $host "DVI File" /usr/local/bin/dvips -f ) | eval /usr/local/libexec/lprps $orig_args - Notice how the filter has to parse the argument list in order to - determine the user and host name. The parsing for the other - conversion filters is identical. The text filter takes a slightly - different set of arguments, though (see section How Filters - Work). - - As we have mentioned before, the above scheme, though fairly - simple, disables the “suppress header page” option (the - option) to lpr. If users - wanted to save a tree (or a few pennies, if you charge for header - pages), they would not be able to do so, since every filter's going - to print a header page with every job. - - To allow users to shut off header pages on a per-job basis, you - will need to use the trick introduced in section Accounting for - Header Pages: write an output filter that parses the - LPD-generated header page and produces a PostScript version. If the - user submits the job with lpr -h, then LPD will - not generate a header page, and neither will your output filter. - Otherwise, your output filter will read the text from LPD and send - the appropriate header page PostScript code to the printer. - - If you have a PostScript printer on a serial line, you can make - use of lprps, which comes with an output filter, - psof, which does the above. Note that - psof does not charge for header pages. + Notice how the filter has to parse the argument list in order to + determine the user and host name. The parsing for the other + conversion filters is identical. The text filter takes a slightly + different set of arguments, though (see section How Filters + Work). + + As we have mentioned before, the above scheme, though fairly + simple, disables the “suppress header page” option (the + option) to lpr. If users + wanted to save a tree (or a few pennies, if you charge for header + pages), they would not be able to do so, since every filter's going + to print a header page with every job. + + To allow users to shut off header pages on a per-job basis, you + will need to use the trick introduced in section Accounting for + Header Pages: write an output filter that parses the + LPD-generated header page and produces a PostScript version. If the + user submits the job with lpr -h, then LPD will + not generate a header page, and neither will your output filter. + Otherwise, your output filter will read the text from LPD and send + the appropriate header page PostScript code to the printer. + + If you have a PostScript printer on a serial line, you can make + use of lprps, which comes with an output filter, + psof, which does the above. Note that + psof does not charge for header pages. + + + + + Networked Printing + + FreeBSD supports networked printing: sending jobs to remote + printers. Networked printing generally refers to two different + things: + + + + Accessing a printer attached to a remote host. You install a + printer that has a conventional serial or parallel interface on + one host. Then, you set up LPD to enable access to the printer + from other hosts on the network. Section Printers Installed on + Remote Hosts tells how to do this. + + + + Accessing a printer attached directly to a network. The + printer has a network interface in addition (or in place of) a + more conventional serial or parallel interface. Such a printer + might work as follows: + + + + It might understand the LPD protocol and can even queue + jobs from remote hosts. In this case, it acts just like a + regular host running LPD. Follow the same procedure in + section Printers + Installed on Remote Hosts to set up such a + printer. + + + + It might support a data stream network connection. In this + case, you “attach” the printer to one host on the + network by making that host responsible for spooling jobs and + sending them to the printer. Section Printers with + Networked Data Stream Interfaces gives some + suggestions on installing such printers. + + + + + + + Printers Installed on Remote Hosts + + The LPD spooling system has built-in support for sending jobs to + other hosts also running LPD (or are compatible with LPD). This + feature enables you to install a printer on one host and make it + accessible from other hosts. It also works with printers that have + network interfaces that understand the LPD protocol. + + To enable this kind of remote printing, first install a printer + on one host, the printer host, using the simple + printer setup described in Simple + Printer Setup. Do any advanced setup in Advanced Printer Setup that you + need. Make sure to test the printer and see if it works with the + features of LPD you have enabled. Also ensure that the + local host has authorization to use the LPD + service in the remote host (see Restricting Jobs + from Remote Printers). + + If you are using a printer with a network interface that is + compatible with LPD, then the printer host in + the discussion below is the printer itself, and the + printer name is the name you configured for the + printer. See the documentation that accompanied your printer and/or + printer-network interface. + + + If you are using a Hewlett Packard Laserjet then the printer + name text will automatically perform the LF to + CRLF conversion for you, so you will not require the + hpif script. + + + Then, on the other hosts you want to have access to the printer, + make an entry in their /etc/printcap files with + the following: + + + + Name the entry anything you want. For simplicity, though, + you probably want to use the same name and aliases as on the + printer host. + + + + Leave the lp capability blank, explicitly + (:lp=:). + + + + Make a spooling directory and specify its location in the + sd capability. LPD will store jobs here + before they get sent to the printer host. + + + + Place the name of the printer host in the + rm capability. + + + + Place the printer name on the printer + host in the rp + capability. + + + + That is it. You do not need to list conversion filters, page + dimensions, or anything else in the + /etc/printcap file. + + Here is an example. The host rose has two + printers, bamboo and rattan. + We will enable users on the host orchid to print to those printers. + Here is the /etc/printcap file for + orchid (back from section Enabling Header + Pages). It already had the entry for the printer + teak; we have added entries for the two printers + on the host rose: + + +# +# /etc/printcap for host orchid - added (remote) printers on rose +# + +# +# teak is local; it is connected directly to orchid: +# +teak|hp|laserjet|Hewlett Packard LaserJet 3Si:\ + :lp=/dev/lpt0:sd=/var/spool/lpd/teak:mx#0:\ + :if=/usr/local/libexec/ifhp:\ + :vf=/usr/local/libexec/vfhp:\ + :of=/usr/local/libexec/ofhp: + +# +# rattan is connected to rose; send jobs for rattan to rose: +# +rattan|line|diablo|lp|Diablo 630 Line Printer:\ + :lp=:rm=rose:rp=rattan:sd=/var/spool/lpd/rattan: + +# +# bamboo is connected to rose as well: +# +bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4:\ + :lp=:rm=rose:rp=bamboo:sd=/var/spool/lpd/bamboo: + + Then, we just need to make spooling directories on + orchid: + + &prompt.root; mkdir -p /var/spool/lpd/rattan /var/spool/lpd/bamboo +&prompt.root; chmod 770 /var/spool/lpd/rattan /var/spool/lpd/bamboo +&prompt.root; chown daemon.daemon /var/spool/lpd/rattan /var/spool/lpd/bamboo + + Now, users on orchid can print to + rattan and bamboo. If, for + example, a user on orchid typed + + &prompt.user; lpr -P bamboo -d sushi-review.dvi + + the LPD system on orchid would copy the job to the spooling + directory /var/spool/lpd/bamboo and note that + it was a DVI job. As soon as the host rose has room in its + bamboo spooling directory, the two LPDs would + transfer the file to rose. The file would wait in rose's queue + until it was finally printed. It would be converted from DVI to + PostScript (since bamboo is a PostScript printer) on rose. + + + + Printers with Networked Data Stream Interfaces + + Often, when you buy a network interface card for a printer, you + can get two versions: one which emulates a spooler (the more + expensive version), or one which just lets you send data to it as if + you were using a serial or parallel port (the cheaper version). + This section tells how to use the cheaper version. For the more + expensive one, see the previous section Printers Installed on + Remote Hosts. + + The format of the /etc/printcap file lets + you specify what serial or parallel interface to use, and (if you + are using a serial interface), what baud rate, whether to use flow + control, delays for tabs, conversion of newlines, and more. But + there is no way to specify a connection to a printer that is + listening on a TCP/IP or other network port. + + To send data to a networked printer, you need to develop a + communications program that can be called by the text and conversion + filters. Here is one such example: the script + netprint takes all data on standard input and + sends it to a network-attached printer. We specify the hostname of + the printer as the first argument and the port number to which to + connect as the second argument to netprint. Note + that this supports one-way communication only (FreeBSD to printer); + many network printers support two-way communication, and you might + want to take advantage of that (to get printer status, perform + accounting, etc.). + + +#!/usr/bin/perl +# +# netprint - Text filter for printer attached to network +# Installed in /usr/local/libexec/netprint +# +$#ARGV eq 1 || die "Usage: $0 <printer-hostname> <port-number>"; + +$printer_host = $ARGV[0]; +$printer_port = $ARGV[1]; + +require 'sys/socket.ph'; + +($ignore, $ignore, $protocol) = getprotobyname('tcp'); +($ignore, $ignore, $ignore, $ignore, $address) + = gethostbyname($printer_host); + +$sockaddr = pack('S n a4 x8', &AF_INET, $printer_port, $address); + +socket(PRINTER, &PF_INET, &SOCK_STREAM, $protocol) + || die "Can't create TCP/IP stream socket: $!"; +connect(PRINTER, $sockaddr) || die "Can't contact $printer_host: $!"; +while (<STDIN>) { print PRINTER; } +exit 0; + + We can then use this script in various filters. Suppose we had + a Diablo 750-N line printer connected to the network. The printer + accepts data to print on port number 5100. The host name of the + printer is scrivener. Here is the text filter for the + printer: + + +#!/bin/sh +# +# diablo-if-net - Text filter for Diablo printer `scrivener' listening +# on port 5100. Installed in /usr/local/libexec/diablo-if-net +# +exec /usr/libexec/lpr/lpf "$@" | /usr/local/libexec/netprint scrivener 5100 + + + + + Restricting Printer Usage + + This section gives information on restricting printer usage. The + LPD system lets you control who can access a printer, both locally or + remotely, whether they can print multiple copies, how large their jobs + can be, and how large the printer queues can get. + + + Restricting Multiple Copies + + The LPD system makes it easy for users to print multiple copies + of a file. Users can print jobs with lpr -#5 + (for example) and get five copies of each file in the job. Whether + this is a good thing is up to you. + + If you feel multiple copies cause unnecessary wear and tear on + your printers, you can disable the option to + &man.lpr.1; by adding the sc capability to the + /etc/printcap file. When users submit jobs + with the option, they will see: + + lpr: multiple copies are not allowed + + + Note that if you have set up access to a printer remotely (see + section Printers + Installed on Remote Hosts), you need the + sc capability on the remote + /etc/printcap files as well, or else users will + still be able to submit multiple-copy jobs by using another + host. + + Here is an example. This is the + /etc/printcap file for the host + rose. The printer rattan is + quite hearty, so we will allow multiple copies, but the laser + printer bamboo's a bit more delicate, so we will + disable multiple copies by adding the sc + capability: + + +# +# /etc/printcap for host rose - restrict multiple copies on bamboo +# +rattan|line|diablo|lp|Diablo 630 Line Printer:\ + :sh:sd=/var/spool/lpd/rattan:\ + :lp=/dev/lpt0:\ + :if=/usr/local/libexec/if-simple: + +bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4:\ + :sh:sd=/var/spool/lpd/bamboo:sc:\ + :lp=/dev/ttyd5:fs#0x82000e1:xs#0x820:rw:\ + :if=/usr/local/libexec/psif:\ + :df=/usr/local/libexec/psdf: + + Now, we also need to add the sc capability on + the host orchid's + /etc/printcap (and while we are at it, let us + disable multiple copies for the printer + teak): + + +# +# /etc/printcap for host orchid - no multiple copies for local +# printer teak or remote printer bamboo +teak|hp|laserjet|Hewlett Packard LaserJet 3Si:\ + :lp=/dev/lpt0:sd=/var/spool/lpd/teak:mx#0:sc:\ + :if=/usr/local/libexec/ifhp:\ + :vf=/usr/local/libexec/vfhp:\ + :of=/usr/local/libexec/ofhp: + +rattan|line|diablo|lp|Diablo 630 Line Printer:\ + :lp=:rm=rose:rp=rattan:sd=/var/spool/lpd/rattan: + +bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4:\ + :lp=:rm=rose:rp=bamboo:sd=/var/spool/lpd/bamboo:sc: + + By using the sc capability, we prevent the + use of lpr -#, but that still does not prevent + users from running &man.lpr.1; + multiple times, or from submitting the same file multiple times in + one job like this: + + &prompt.user; lpr forsale.sign forsale.sign forsale.sign forsale.sign forsale.sign + + There are many ways to prevent this abuse (including ignoring + it) which you are free to explore. + + + + Restricting Access To Printers + + You can control who can print to what printers by using the UNIX + group mechanism and the rg capability in + /etc/printcap. Just place the users you want + to have access to a printer in a certain group, and then name that + group in the rg capability. + + Users outside the group (including root) will be greeted with + + lpr: Not a member of the restricted group + + if they try to print to the controlled printer. + + As with the sc (suppress multiple copies) + capability, you need to specify rg on remote + hosts that also have access to your printers, if you feel it is + appropriate (see section Printers Installed on + Remote Hosts). + + For example, we will let anyone access the printer + rattan, but only those in group + artists can use bamboo. Here + is the familiar /etc/printcap for host + rose: + + +# +# /etc/printcap for host rose - restricted group for bamboo +# +rattan|line|diablo|lp|Diablo 630 Line Printer:\ + :sh:sd=/var/spool/lpd/rattan:\ + :lp=/dev/lpt0:\ + :if=/usr/local/libexec/if-simple: + +bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4:\ + :sh:sd=/var/spool/lpd/bamboo:sc:rg=artists:\ + :lp=/dev/ttyd5:fs#0x82000e1:xs#0x820:rw:\ + :if=/usr/local/libexec/psif:\ + :df=/usr/local/libexec/psdf: + + Let us leave the other example + /etc/printcap file (for the host + orchid) alone. Of course, anyone on + orchid can print to bamboo. It + might be the case that we only allow certain logins on + orchid anyway, and want them to have access to the + printer. Or not. + + + There can be only one restricted group per printer. + + + + + Controlling Sizes of Jobs Submitted + + If you have many users accessing the printers, you probably need + to put an upper limit on the sizes of the files users can submit to + print. After all, there is only so much free space on the + filesystem that houses the spooling directories, and you also need + to make sure there is room for the jobs of other users. + + LPD enables you to limit the maximum byte size a file in a job + can be with the mx capability. The units are in + BUFSIZ blocks, which are 1024 bytes. If you put a zero for this + capability, there will be no limit on file size; however, if no + mx capability is specified, then a default limit + of 1000 blocks will be used. + + + The limit applies to files in a job, and + not the total job size. + + + LPD will not refuse a file that is larger than the limit you + place on a printer. Instead, it will queue as much of the file up + to the limit, which will then get printed. The rest will be + discarded. Whether this is correct behavior is up for + debate. + + Let us add limits to our example printers + rattan and bamboo. Since + those artists' PostScript files tend to be large, we will limit them + to five megabytes. We will put no limit on the plain text line + printer: + + +# +# /etc/printcap for host rose +# + +# +# No limit on job size: +# +rattan|line|diablo|lp|Diablo 630 Line Printer:\ + :sh:mx#0:sd=/var/spool/lpd/rattan:\ + :lp=/dev/lpt0:\ + :if=/usr/local/libexec/if-simple: + +# +# Limit of five megabytes: +# +bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4:\ + :sh:sd=/var/spool/lpd/bamboo:sc:rg=artists:mx#5000:\ + :lp=/dev/ttyd5:fs#0x82000e1:xs#0x820:rw:\ + :if=/usr/local/libexec/psif:\ + :df=/usr/local/libexec/psdf: + + Again, the limits apply to the local users only. If you have + set up access to your printers remotely, remote users will not get + those limits. You will need to specify the mx + capability in the remote /etc/printcap files as + well. See section Printers Installed on + Remote Hosts for more information on remote + printing. + + There is another specialized way to limit job sizes from remote + printers; see section Restricting Jobs + from Remote Printers. + + + + Restricting Jobs from Remote Printers + + The LPD spooling system provides several ways to restrict print + jobs submitted from remote hosts: + + + + Host restrictions + + + You can control from which remote hosts a local LPD + accepts requests with the files + /etc/hosts.equiv and + /etc/hosts.lpd. LPD checks to see if an + incoming request is from a host listed in either one of these + files. If not, LPD refuses the request. + + The format of these files is simple: one host name per + line. Note that the file + /etc/hosts.equiv is also used by the + &man.ruserok.3; protocol, and affects programs like + &man.rsh.1; and &man.rcp.1;, so be careful. + + For example, here is the + /etc/hosts.lpd file on the host + rose: + + +orchid +violet +madrigal.fishbaum.de + + This means rose will accept requests from + the hosts orchid, violet, + and madrigal.fishbaum.de. If any + other host tries to access rose's LPD, LPD + will refuse them. + + + + + Size restrictions + + + You can control how much free space there needs to remain + on the filesystem where a spooling directory resides. Make a + file called minfree in the spooling + directory for the local printer. Insert in that file a number + representing how many disk blocks (512 bytes) of free space + there has to be for a remote job to be accepted. + + This lets you insure that remote users will not fill your + filesystem. You can also use it to give a certain priority to + local users: they will be able to queue jobs long after the + free disk space has fallen below the amount specified in the + minfree file. + + For example, let us add a minfree + file for the printer bamboo. We examine + /etc/printcap to find the spooling + directory for this printer; here is bamboo's + entry: + + +bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4:\ + :sh:sd=/var/spool/lpd/bamboo:sc:rg=artists:mx#5000:\ + :lp=/dev/ttyd5:fs#0x82000e1:xs#0x820:rw:mx#5000:\ + :if=/usr/local/libexec/psif:\ + :df=/usr/local/libexec/psdf: + + The spooling directory is the given in the + sd capability. We will make three + megabytes (which is 6144 disk blocks) the amount of free disk + space that must exist on the filesystem for LPD to accept + remote jobs: + + &prompt.root; echo 6144 > /var/spool/lpd/bam +boo/minfree + + + + + User restrictions + + + You can control which remote users can print to local + printers by specifying the rs capability in + /etc/printcap. When + rs appears in the entry for a + locally-attached printer, LPD will accept jobs from remote + hosts if the user submitting the job also + has an account of the same login name on the local host. + Otherwise, LPD refuses the job. + + This capability is particularly useful in an environment + where there are (for example) different departments sharing a + network, and some users transcend departmental boundaries. By + giving them accounts on your systems, they can use your + printers from their own departmental systems. If you would + rather allow them to use only your + printers and not your compute resources, you can give them + “token” accounts, with no home directory and a + useless shell like /usr/bin/false. + + + + + + + + Accounting for Printer Usage + + So, you need to charge for printouts. And why not? Paper and ink + cost money. And then there are maintenance costs—printers are + loaded with moving parts and tend to break down. You have examined + your printers, usage patterns, and maintenance fees and have come up + with a per-page (or per-foot, per-meter, or per-whatever) cost. Now, + how do you actually start accounting for printouts? + + Well, the bad news is the LPD spooling system does not provide + much help in this department. Accounting is highly dependent on the + kind of printer in use, the formats being printed, and + your requirements in charging for printer + usage. + + To implement accounting, you have to modify a printer's text + filter (to charge for plain text jobs) and the conversion filters (to + charge for other file formats), to count pages or query the printer + for pages printed. You cannot get away with using the simple output + filter, since it cannot do accounting. See section Filters. + + Generally, there are two ways to do accounting: + + + + Periodic accounting is the more common + way, possibly because it is easier. Whenever someone prints a + job, the filter logs the user, host, and number of pages to an + accounting file. Every month, semester, year, or whatever time + period you prefer, you collect the accounting files for the + various printers, tally up the pages printed by users, and charge + for usage. Then you truncate all the logging files, starting with + a clean slate for the next period. + + + + Timely accounting is less common, + probably because it is more difficult. This method has the + filters charge users for printouts as soon as they use the + printers. Like disk quotas, the accounting is immediate. You can + prevent users from printing when their account goes in the red, + and might provide a way for users to check and adjust their + “print quotas.” But this method requires some database + code to track users and their quotas. + + + + The LPD spooling system supports both methods easily: since you + have to provide the filters (well, most of the time), you also have to + provide the accounting code. But there is a bright side: you have + enormous flexibility in your accounting methods. For example, you + choose whether to use periodic or timely accounting. You choose what + information to log: user names, host names, job types, pages printed, + square footage of paper used, how long the job took to print, and so + forth. And you do so by modifying the filters to save this + information. + + + Quick and Dirty Printer Accounting + + FreeBSD comes with two programs that can get you set up with + simple periodic accounting right away. They are the text filter + lpf, described in section lpf: a Text Filter, and + &man.pac.8;, a program to gather and total + entries from printer accounting files. + + As mentioned in the section on filters (Filters), LPD starts + the text and the conversion filters with the name of the accounting + file to use on the filter command line. The filters can use this + argument to know where to write an accounting file entry. The name + of this file comes from the af capability in + /etc/printcap, and if not specified as an + absolute path, is relative to the spooling directory. + + LPD starts lpf with page width and length + arguments (from the pw and pl + capabilities). lpf uses these arguments to + determine how much paper will be used. After sending the file to + the printer, it then writes an accounting entry in the accounting + file. The entries look like this: + + +2.00 rose:andy +3.00 rose:kelly +3.00 orchid:mary +5.00 orchid:mary +2.00 orchid:zhang + + You should use a separate accounting file for each printer, as + lpf has no file locking logic built into it, and + two lpfs might corrupt each other's entries if + they were to write to the same file at the same time. A easy way to + insure a separate accounting file for each printer is to use + af=acct in /etc/printcap. + Then, each accounting file will be in the spooling directory for a + printer, in a file named acct. + + When you are ready to charge users for printouts, run the + &man.pac.8; program. Just change to the spooling directory for + the printer you want to collect on and type pac. + You will get a dollar-centric summary like the following: + + Login pages/feet runs price +orchid:kelly 5.00 1 $ 0.10 +orchid:mary 31.00 3 $ 0.62 +orchid:zhang 9.00 1 $ 0.18 +rose:andy 2.00 1 $ 0.04 +rose:kelly 177.00 104 $ 3.54 +rose:mary 87.00 32 $ 1.74 +rose:root 26.00 12 $ 0.52 + +total 337.00 154 $ 6.74 + + These are the arguments &man.pac.8; expects: + + + + + + + Which printer to summarize. + This option works only if there is an absolute path in the + af capability in + /etc/printcap. + + + + + + + + Sort the output by cost instead of alphabetically by user + name. + + + + + + + + Ignore host name in the accounting files. With this + option, user smith on host + alpha is the same user + smith on host gamma. + Without, they are different users. + + + + + + + + Compute charges with price + dollars per page or per foot instead of the price from the + pc capability in + /etc/printcap, or two cents (the + default). You can specify price as + a floating point number. + + + + + + + + Reverse the sort order. + + + + + + + + Make an accounting summary file and truncate the + accounting file. + + + + + name + … + + + Print accounting information for the given user + names only. + + + + + In the default summary that &man.pac.8; produces, you see the + number of pages printed by each user from various hosts. If, at + your site, host does not matter (because users can use any host), + run pac -m, to produce the following + summary: + + Login pages/feet runs price +andy 2.00 1 $ 0.04 +kelly 182.00 105 $ 3.64 +mary 118.00 35 $ 2.36 +root 26.00 12 $ 0.52 +zhang 9.00 1 $ 0.18 + +total 337.00 154 $ 6.74 + + + To compute the dollar amount due, + &man.pac.8; uses the pc capability in the + /etc/printcap file (default of 200, or 2 cents + per page). Specify, in hundredths of cents, the price per page or + per foot you want to charge for printouts in this capability. You + can override this value when you run &man.pac.8; with the + option. The units for the + option are in dollars, though, not hundredths of cents. For + example, + + &prompt.root; pac -p1.50 + + makes each page cost one dollar and fifty cents. You can really + rake in the profits by using this option. + + Finally, running pac -s will save the summary + information in a summary accounting file, which is named the same as + the printer's accounting file, but with _sum + appended to the name. It then truncates the accounting file. When + you run &man.pac.8; again, it rereads the + summary file to get starting totals, then adds information from the + regular accounting file. + + + + How Can You Count Pages Printed? + + In order to perform even remotely accurate accounting, you need + to be able to determine how much paper a job uses. This is the + essential problem of printer accounting. + + For plain text jobs, the problem's not that hard to solve: you + count how many lines are in a job and compare it to how many lines + per page your printer supports. Do not forget to take into account + backspaces in the file which overprint lines, or long logical lines + that wrap onto one or more additional physical lines. + + The text filter lpf (introduced in lpf: a Text Filter) takes + into account these things when it does accounting. If you are + writing a text filter which needs to do accounting, you might want + to examine lpf's source code. + + How do you handle other file formats, though? + + Well, for DVI-to-LaserJet or DVI-to-PostScript conversion, you + can have your filter parse the diagnostic output of + dvilj or dvips and look to see + how many pages were converted. You might be able to do similar + things with other file formats and conversion programs. + + But these methods suffer from the fact that the printer may not + actually print all those pages. For example, it could jam, run out + of toner, or explode—and the user would still get + charged. + + So, what can you do? + + There is only one sure way to do + accurate accounting. Get a printer that can + tell you how much paper it uses, and attach it via a serial line or + a network connection. Nearly all PostScript printers support this + notion. Other makes and models do as well (networked Imagen laser + printers, for example). Modify the filters for these printers to + get the page usage after they print each job and have them log + accounting information based on that value + only. There is no line counting nor + error-prone file examination required. + + Of course, you can always be generous and make all printouts + free. + + + + Using Printers - - Networked Printing - - FreeBSD supports networked printing: sending jobs to remote - printers. Networked printing generally refers to two different - things: + This section tells you how to use printers you have setup with + FreeBSD. Here is an overview of the user-level commands: + + + + &man.lpr.1; + + + Print jobs + + - + + &man.lpq.1; + - Accessing a printer attached to a remote host. You install a - printer that has a conventional serial or parallel interface on - one host. Then, you set up LPD to enable access to the printer - from other hosts on the network. Section Printers Installed on - Remote Hosts tells how to do this. + Check printer queues + + + + &man.lprm.1; - Accessing a printer attached directly to a network. The - printer has a network interface in addition (or in place of) a - more conventional serial or parallel interface. Such a printer - might work as follows: - - - - It might understand the LPD protocol and can even queue - jobs from remote hosts. In this case, it acts just like a - regular host running LPD. Follow the same procedure in - section Printers - Installed on Remote Hosts to set up such a - printer. - - - - It might support a data stream network connection. In this - case, you “attach” the printer to one host on the - network by making that host responsible for spooling jobs and - sending them to the printer. Section Printers with - Networked Data Stream Interfaces gives some - suggestions on installing such printers. - - + Remove jobs from a printer's queue - - - - Printers Installed on Remote Hosts + + + + There is also an administrative command, &man.lpc.8;, described in + the section Administrating the LPD + Spooler, used to control printers and their queues. - The LPD spooling system has built-in support for sending jobs to - other hosts also running LPD (or are compatible with LPD). This - feature enables you to install a printer on one host and make it - accessible from other hosts. It also works with printers that have - network interfaces that understand the LPD protocol. - - To enable this kind of remote printing, first install a printer - on one host, the printer host, using the simple - printer setup described in Simple - Printer Setup. Do any advanced setup in Advanced Printer Setup that you - need. Make sure to test the printer and see if it works with the - features of LPD you have enabled. Also ensure that the - local host has authorization to use the LPD - service in the remote host (see Restricting Jobs - from Remote Printers). - - If you are using a printer with a network interface that is - compatible with LPD, then the printer host in - the discussion below is the printer itself, and the - printer name is the name you configured for the - printer. See the documentation that accompanied your printer and/or - printer-network interface. - - - If you are using a Hewlett Packard Laserjet then the printer - name text will automatically perform the LF to - CRLF conversion for you, so you will not require the - hpif script. - + All three of the commands &man.lpr.1;, &man.lprm.1;, and &man.lpq.1; + accept an option to specify on which + printer/queue to operate, as listed in the + /etc/printcap file. This enables you to submit, + remove, and check on jobs for various printers. If you do not use the + option, then these commands use the printer + specified in the PRINTER environment variable. Finally, + if you do not have a PRINTER environment variable, these + commands default to the printer named lp. + + Hereafter, the terminology default printer + means the printer named in the PRINTER environment + variable, or the printer named lp when there is no + PRINTER environment variable. + + + Printing Jobs + + To print files, type: + + &prompt.user; lpr filename ... - Then, on the other hosts you want to have access to the printer, - make an entry in their /etc/printcap files with - the following: + This prints each of the listed files to the default printer. If + you list no files, &man.lpr.1; reads data to + print from standard input. For example, this command prints some + important system files: - - - Name the entry anything you want. For simplicity, though, - you probably want to use the same name and aliases as on the - printer host. - - - - Leave the lp capability blank, explicitly - (:lp=:). - - - - Make a spooling directory and specify its location in the - sd capability. LPD will store jobs here - before they get sent to the printer host. - - - - Place the name of the printer host in the - rm capability. - - - - Place the printer name on the printer - host in the rp - capability. - - - - That is it. You do not need to list conversion filters, page - dimensions, or anything else in the - /etc/printcap file. - - Here is an example. The host rose has two - printers, bamboo and rattan. - We will enable users on the host orchid to print to those printers. - Here is the /etc/printcap file for - orchid (back from section Enabling Header - Pages). It already had the entry for the printer - teak; we have added entries for the two printers - on the host rose: - - -# -# /etc/printcap for host orchid - added (remote) printers on rose -# + &prompt.user; lpr /etc/host.conf /etc/hosts.equiv + + To select a specific printer, type: + + &prompt.user; lpr -P printer-name filename ... -# -# teak is local; it is connected directly to orchid: -# -teak|hp|laserjet|Hewlett Packard LaserJet 3Si:\ - :lp=/dev/lpt0:sd=/var/spool/lpd/teak:mx#0:\ - :if=/usr/local/libexec/ifhp:\ - :vf=/usr/local/libexec/vfhp:\ - :of=/usr/local/libexec/ofhp: + This example prints a long listing of the current directory to the + printer named rattan: + + &prompt.user; ls -l | lpr -P rattan + + Because no files were listed for the + &man.lpr.1; command, lpr read the data to print + from standard input, which was the output of the ls + -l command. + + The &man.lpr.1; command can also accept a wide variety of options + to control formatting, apply file conversions, generate multiple + copies, and so forth. For more information, see the section Printing Options. + + + + Checking Jobs + + When you print with &man.lpr.1;, the data you wish to print is put + together in a package called a “print job”, which is sent + to the LPD spooling system. Each printer has a queue of jobs, and + your job waits in that queue along with other jobs from yourself and + from other users. The printer prints those jobs in a first-come, + first-served order. -# -# rattan is connected to rose; send jobs for rattan to rose: -# -rattan|line|diablo|lp|Diablo 630 Line Printer:\ - :lp=:rm=rose:rp=rattan:sd=/var/spool/lpd/rattan: + To display the queue for the default printer, type &man.lpq.1;. + For a specific printer, use the option. For + example, the command -# -# bamboo is connected to rose as well: -# -bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4:\ - :lp=:rm=rose:rp=bamboo:sd=/var/spool/lpd/bamboo: + &prompt.user; lpq -P bamboo - Then, we just need to make spooling directories on - orchid: - - &prompt.root; mkdir -p /var/spool/lpd/rattan /var/spool/lpd/bamboo -&prompt.root; chmod 770 /var/spool/lpd/rattan /var/spool/lpd/bamboo -&prompt.root; chown daemon.daemon /var/spool/lpd/rattan /var/spool/lpd/bamboo - - Now, users on orchid can print to - rattan and bamboo. If, for - example, a user on orchid typed - - &prompt.user; lpr -P bamboo -d sushi-review.dvi - - the LPD system on orchid would copy the job to the spooling - directory /var/spool/lpd/bamboo and note that - it was a DVI job. As soon as the host rose has room in its - bamboo spooling directory, the two LPDs would - transfer the file to rose. The file would wait in rose's queue - until it was finally printed. It would be converted from DVI to - PostScript (since bamboo is a PostScript printer) on rose. - - - - Printers with Networked Data Stream Interfaces - - Often, when you buy a network interface card for a printer, you - can get two versions: one which emulates a spooler (the more - expensive version), or one which just lets you send data to it as if - you were using a serial or parallel port (the cheaper version). - This section tells how to use the cheaper version. For the more - expensive one, see the previous section Printers Installed on - Remote Hosts. + shows the queue for the printer named bamboo. Here + is an example of the output of the lpq + command: - The format of the /etc/printcap file lets - you specify what serial or parallel interface to use, and (if you - are using a serial interface), what baud rate, whether to use flow - control, delays for tabs, conversion of newlines, and more. But - there is no way to specify a connection to a printer that is - listening on a TCP/IP or other network port. + bamboo is ready and printing +Rank Owner Job Files Total Size +active kelly 9 /etc/host.conf, /etc/hosts.equiv 88 bytes +2nd kelly 10 (standard input) 1635 bytes +3rd mary 11 ... 78519 bytes - To send data to a networked printer, you need to develop a - communications program that can be called by the text and conversion - filters. Here is one such example: the script - netprint takes all data on standard input and - sends it to a network-attached printer. We specify the hostname of - the printer as the first argument and the port number to which to - connect as the second argument to netprint. Note - that this supports one-way communication only (FreeBSD to printer); - many network printers support two-way communication, and you might - want to take advantage of that (to get printer status, perform - accounting, etc.). - - -#!/usr/bin/perl -# -# netprint - Text filter for printer attached to network -# Installed in /usr/local/libexec/netprint -# -$#ARGV eq 1 || die "Usage: $0 <printer-hostname> <port-number>"; + This shows three jobs in the queue for bamboo. + The first job, submitted by user kelly, got assigned “job + number” 9. Every job for a printer gets a unique job number. + Most of the time you can ignore the job number, but you will need it + if you want to cancel the job; see section Removing Jobs for details. + + Job number nine consists of two files; multiple files given on the + &man.lpr.1; command line are treated as part of a single job. It + is the currently active job (note the word active + under the “Rank” column), which means the printer should + be currently printing that job. The second job consists of data + passed as the standard input to the &man.lpr.1; command. The third + job came from user mary; it is a much larger + job. The pathname of the files she's trying to print is too long to + fit, so the &man.lpq.1; command just shows three dots. -$printer_host = $ARGV[0]; -$printer_port = $ARGV[1]; + The very first line of the output from &man.lpq.1; is also useful: + it tells what the printer is currently doing (or at least what LPD + thinks the printer is doing). -require 'sys/socket.ph'; + The &man.lpq.1; command also support a option + to generate a detailed long listing. Here is an example of + lpq -l: + + waiting for bamboo to become ready (offline ?) +kelly: 1st [job 009rose] + /etc/host.conf 73 bytes + /etc/hosts.equiv 15 bytes -($ignore, $ignore, $protocol) = getprotobyname('tcp'); -($ignore, $ignore, $ignore, $ignore, $address) - = gethostbyname($printer_host); +kelly: 2nd [job 010rose] + (standard input) 1635 bytes -$sockaddr = pack('S n a4 x8', &AF_INET, $printer_port, $address); +mary: 3rd [job 011rose] + /home/orchid/mary/research/venus/alpha-regio/mapping 78519 bytes + -socket(PRINTER, &PF_INET, &SOCK_STREAM, $protocol) - || die "Can't create TCP/IP stream socket: $!"; -connect(PRINTER, $sockaddr) || die "Can't contact $printer_host: $!"; -while (<STDIN>) { print PRINTER; } -exit 0; + + Removing Jobs + + If you change your mind about printing a job, you can remove the + job from the queue with the &man.lprm.1; command. Often, you can + even use &man.lprm.1; to remove an active job, but some or all of the + job might still get printed. + + To remove a job from the default printer, first use + &man.lpq.1; to find the job number. Then type: + + &prompt.user; lprm job-number - We can then use this script in various filters. Suppose we had - a Diablo 750-N line printer connected to the network. The printer - accepts data to print on port number 5100. The host name of the - printer is scrivener. Here is the text filter for the - printer: + To remove the job from a specific printer, add the + option. The following command removes job number + 10 from the queue for the printer bamboo: + + &prompt.user; lprm -P bamboo 10 + + The &man.lprm.1; command has a few shortcuts: + + + + lprm - - -#!/bin/sh -# -# diablo-if-net - Text filter for Diablo printer `scrivener' listening -# on port 5100. Installed in /usr/local/libexec/diablo-if-net -# -exec /usr/libexec/lpr/lpf "$@" | /usr/local/libexec/netprint scrivener 5100 - + + Removes all jobs (for the default printer) belonging to + you. + + + + + lprm user + + + Removes all jobs (for the default printer) belonging to + user. The superuser can remove other + users' jobs; you can remove only your own jobs. + + + + + lprm + + + With no job number, user name, or + appearing on the command line, + &man.lprm.1; removes the currently active job on the + default printer, if it belongs to you. The superuser can remove + any active job. + + + + + Just use the option with the above shortcuts + to operate on a specific printer instead of the default. For example, + the following command removes all jobs for the current user in the + queue for the printer named rattan: + + &prompt.user; lprm -P rattan - + + + If you are working in a networked environment, &man.lprm.1; will + let you remove jobs only from the + host from which the jobs were submitted, even if the same printer is + available from other hosts. The following command sequence + demonstrates this: + + &prompt.user; lpr -P rattan myfile +&prompt.user; rlogin orchid +&prompt.user; lpq -P rattan +Rank Owner Job Files Total Size +active seeyan 12 ... 49123 bytes +2nd kelly 13 myfile 12 bytes +&prompt.user; lprm -P rattan 13 +rose: Permission denied +&prompt.user; logout +&prompt.user; lprm -P rattan 13 +dfA013rose dequeued +cfA013rose dequeued + + - - Restricting Printer Usage - - This section gives information on restricting printer usage. The - LPD system lets you control who can access a printer, both locally or - remotely, whether they can print multiple copies, how large their jobs - can be, and how large the printer queues can get. + + Beyond Plain Text: Printing Options - - Restricting Multiple Copies + The &man.lpr.1; command supports a number of options that control + formatting text, converting graphic and other file formats, producing + multiple copies, handling of the job, and more. This section + describes the options. + + + Formatting and Conversion Options - The LPD system makes it easy for users to print multiple copies - of a file. Users can print jobs with lpr -#5 - (for example) and get five copies of each file in the job. Whether - this is a good thing is up to you. + The following &man.lpr.1; options control formatting of the + files in the job. Use these options if the job does not contain + plain text or if you want plain text formatted through the + &man.pr.1; utility. - If you feel multiple copies cause unnecessary wear and tear on - your printers, you can disable the option to - &man.lpr.1; by adding the sc capability to the - /etc/printcap file. When users submit jobs - with the option, they will see: + For example, the following command prints a DVI file (from the + TeX typesetting system) named fish-report.dvi + to the printer named bamboo: - lpr: multiple copies are not allowed - - - Note that if you have set up access to a printer remotely (see - section Printers - Installed on Remote Hosts), you need the - sc capability on the remote - /etc/printcap files as well, or else users will - still be able to submit multiple-copy jobs by using another - host. - - Here is an example. This is the - /etc/printcap file for the host - rose. The printer rattan is - quite hearty, so we will allow multiple copies, but the laser - printer bamboo's a bit more delicate, so we will - disable multiple copies by adding the sc - capability: - - -# -# /etc/printcap for host rose - restrict multiple copies on bamboo -# -rattan|line|diablo|lp|Diablo 630 Line Printer:\ - :sh:sd=/var/spool/lpd/rattan:\ - :lp=/dev/lpt0:\ - :if=/usr/local/libexec/if-simple: - -bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4:\ - :sh:sd=/var/spool/lpd/bamboo:sc:\ - :lp=/dev/ttyd5:fs#0x82000e1:xs#0x820:rw:\ - :if=/usr/local/libexec/psif:\ - :df=/usr/local/libexec/psdf: - - Now, we also need to add the sc capability on - the host orchid's - /etc/printcap (and while we are at it, let us - disable multiple copies for the printer - teak): + &prompt.user; lpr -P bamboo -d fish-report.dvi + + These options apply to every file in the job, so you cannot mix + (say) DVI and ditroff files together in a job. Instead, submit the + files as separate jobs, using a different conversion option for each + job. - -# -# /etc/printcap for host orchid - no multiple copies for local -# printer teak or remote printer bamboo -teak|hp|laserjet|Hewlett Packard LaserJet 3Si:\ - :lp=/dev/lpt0:sd=/var/spool/lpd/teak:mx#0:sc:\ - :if=/usr/local/libexec/ifhp:\ - :vf=/usr/local/libexec/vfhp:\ - :of=/usr/local/libexec/ofhp: + + All of these options except and + require conversion filters installed for the + destination printer. For example, the option + requires the DVI conversion filter. Section Conversion + Filters gives details. + -rattan|line|diablo|lp|Diablo 630 Line Printer:\ - :lp=:rm=rose:rp=rattan:sd=/var/spool/lpd/rattan: + + + -bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4:\ - :lp=:rm=rose:rp=bamboo:sd=/var/spool/lpd/bamboo:sc: + + Print cifplot files. + + + + + - By using the sc capability, we prevent the - use of lpr -#, but that still does not prevent - users from running &man.lpr.1; - multiple times, or from submitting the same file multiple times in - one job like this: - - &prompt.user; lpr forsale.sign forsale.sign forsale.sign forsale.sign forsale.sign - - There are many ways to prevent this abuse (including ignoring - it) which you are free to explore. - - - - Restricting Access To Printers + + Print DVI files. + + + + + + + + Print FORTRAN text files. + + + + + + + + Print plot data. + + + + + + + + Indent the output by number + columns; if you omit number, indent + by 8 columns. This option works only with certain conversion + filters. - You can control who can print to what printers by using the UNIX - group mechanism and the rg capability in - /etc/printcap. Just place the users you want - to have access to a printer in a certain group, and then name that - group in the rg capability. + + Do not put any space between the and + the number. + + + + + + - Users outside the group (including root) will be greeted with + + Print literal text data, including control + characters. + + - lpr: Not a member of the restricted group + + + + + Print ditroff (device independent troff) data. + + - if they try to print to the controlled printer. - - As with the sc (suppress multiple copies) - capability, you need to specify rg on remote - hosts that also have access to your printers, if you feel it is - appropriate (see section Printers Installed on - Remote Hosts). + + -p - For example, we will let anyone access the printer - rattan, but only those in group - artists can use bamboo. Here - is the familiar /etc/printcap for host - rose: - - -# -# /etc/printcap for host rose - restricted group for bamboo -# -rattan|line|diablo|lp|Diablo 630 Line Printer:\ - :sh:sd=/var/spool/lpd/rattan:\ - :lp=/dev/lpt0:\ - :if=/usr/local/libexec/if-simple: - -bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4:\ - :sh:sd=/var/spool/lpd/bamboo:sc:rg=artists:\ - :lp=/dev/ttyd5:fs#0x82000e1:xs#0x820:rw:\ - :if=/usr/local/libexec/psif:\ - :df=/usr/local/libexec/psdf: - - Let us leave the other example - /etc/printcap file (for the host - orchid) alone. Of course, anyone on - orchid can print to bamboo. It - might be the case that we only allow certain logins on - orchid anyway, and want them to have access to the - printer. Or not. - - - There can be only one restricted group per printer. - - - - - Controlling Sizes of Jobs Submitted - - If you have many users accessing the printers, you probably need - to put an upper limit on the sizes of the files users can submit to - print. After all, there is only so much free space on the - filesystem that houses the spooling directories, and you also need - to make sure there is room for the jobs of other users. + + Format plain text with &man.pr.1; before printing. See + &man.pr.1; for more information. + + + + + - LPD enables you to limit the maximum byte size a file in a job - can be with the mx capability. The units are in - BUFSIZ blocks, which are 1024 bytes. If you put a zero for this - capability, there will be no limit on file size; however, if no - mx capability is specified, then a default limit - of 1000 blocks will be used. - - - The limit applies to files in a job, and - not the total job size. - - - LPD will not refuse a file that is larger than the limit you - place on a printer. Instead, it will queue as much of the file up - to the limit, which will then get printed. The rest will be - discarded. Whether this is correct behavior is up for - debate. + + Use title on the + &man.pr.1; header instead of the file name. This option has + effect only when used with the + option. + + + + + - Let us add limits to our example printers - rattan and bamboo. Since - those artists' PostScript files tend to be large, we will limit them - to five megabytes. We will put no limit on the plain text line - printer: - - -# -# /etc/printcap for host rose -# - -# -# No limit on job size: -# -rattan|line|diablo|lp|Diablo 630 Line Printer:\ - :sh:mx#0:sd=/var/spool/lpd/rattan:\ - :lp=/dev/lpt0:\ - :if=/usr/local/libexec/if-simple: - -# -# Limit of five megabytes: -# -bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4:\ - :sh:sd=/var/spool/lpd/bamboo:sc:rg=artists:mx#5000:\ - :lp=/dev/ttyd5:fs#0x82000e1:xs#0x820:rw:\ - :if=/usr/local/libexec/psif:\ - :df=/usr/local/libexec/psdf: - - Again, the limits apply to the local users only. If you have - set up access to your printers remotely, remote users will not get - those limits. You will need to specify the mx - capability in the remote /etc/printcap files as - well. See section Printers Installed on - Remote Hosts for more information on remote - printing. + + Print troff data. + + + + + + + + Print raster data. + + + + + Here is an example: this command prints a nicely formatted + version of the &man.ls.1; manual page on the default printer: + + &prompt.user; zcat /usr/share/man/man1/ls.1.gz | troff -t -man | lpr -t + + The &man.zcat.1; command uncompresses the source of the + + &man.ls.1; manual page and passes it to the &man.troff.1; + command, which formats that source and makes GNU troff output and + passes it to &man.lpr.1;, which submits the job to the LPD spooler. + Because we used the option to - There is another specialized way to limit job sizes from remote - printers; see section Restricting Jobs - from Remote Printers. + &man.lpr.1;, the spooler will convert the GNU troff output into + a format the default printer can understand when it prints the + job. - - Restricting Jobs from Remote Printers + + Job Handling Options - The LPD spooling system provides several ways to restrict print - jobs submitted from remote hosts: - + The following options to &man.lpr.1; tell LPD to handle the job + specially: + - Host restrictions + -# copies - You can control from which remote hosts a local LPD - accepts requests with the files - /etc/hosts.equiv and - /etc/hosts.lpd. LPD checks to see if an - incoming request is from a host listed in either one of these - files. If not, LPD refuses the request. - - The format of these files is simple: one host name per - line. Note that the file - /etc/hosts.equiv is also used by the - &man.ruserok.3; protocol, and affects programs like - &man.rsh.1; and &man.rcp.1;, so be careful. - - For example, here is the - /etc/hosts.lpd file on the host - rose: + Produce a number of copies of + each file in the job instead of just one copy. An + administrator may disable this option to reduce printer + wear-and-tear and encourage photocopier usage. See section + Restricting + Multiple Copies. - -orchid -violet -madrigal.fishbaum.de - - This means rose will accept requests from - the hosts orchid, violet, - and madrigal.fishbaum.de. If any - other host tries to access rose's LPD, LPD - will refuse them. + This example prints three copies of + parser.c followed by three copies of + parser.h to the default printer: + + &prompt.user; lpr -#3 parser.c parser.h + + + + + -m + + + Send mail after completing the print job. With this + option, the LPD system will send mail to your account when it + finishes handling your job. In its message, it will tell you + if the job completed successfully or if there was an error, + and (often) what the error was. - Size restrictions + -s - You can control how much free space there needs to remain - on the filesystem where a spooling directory resides. Make a - file called minfree in the spooling - directory for the local printer. Insert in that file a number - representing how many disk blocks (512 bytes) of free space - there has to be for a remote job to be accepted. + Do not copy the files to the spooling directory, but make + symbolic links to them instead. - This lets you insure that remote users will not fill your - filesystem. You can also use it to give a certain priority to - local users: they will be able to queue jobs long after the - free disk space has fallen below the amount specified in the - minfree file. + If you are printing a large job, you probably want to use + this option. It saves space in the spooling directory (your + job might overflow the free space on the filesystem where the + spooling directory resides). It saves time as well since LPD + will not have to copy each and every byte of your job to the + spooling directory. - For example, let us add a minfree - file for the printer bamboo. We examine - /etc/printcap to find the spooling - directory for this printer; here is bamboo's - entry: - - -bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4:\ - :sh:sd=/var/spool/lpd/bamboo:sc:rg=artists:mx#5000:\ - :lp=/dev/ttyd5:fs#0x82000e1:xs#0x820:rw:mx#5000:\ - :if=/usr/local/libexec/psif:\ - :df=/usr/local/libexec/psdf: + There is a drawback, though: since LPD will refer to the + original files directly, you cannot modify or remove them + until they have been printed. + + + If you are printing to a remote printer, LPD will + eventually have to copy files from the local host to the + remote host, so the option will save + space only on the local spooling directory, not the remote. + It is still useful, though. + + + + + + -r + + + Remove the files in the job after copying them to the + spooling directory, or after printing them with the + option. Be careful with this + option! + + + + + + + Header Page Options - The spooling directory is the given in the - sd capability. We will make three - megabytes (which is 6144 disk blocks) the amount of free disk - space that must exist on the filesystem for LPD to accept - remote jobs: - - &prompt.root; echo 6144 > /var/spool/lpd/bamboo/minfree + These options to &man.lpr.1; adjust the text that normally + appears on a job's header page. If header pages are suppressed for + the destination printer, these options have no effect. See section + Header Pages + for information about setting up header pages. + + + + -C text + + + Replace the hostname on the header page with + text. The hostname is normally the + name of the host from which the job was submitted. - User restrictions + -J text - You can control which remote users can print to local - printers by specifying the rs capability in - /etc/printcap. When - rs appears in the entry for a - locally-attached printer, LPD will accept jobs from remote - hosts if the user submitting the job also - has an account of the same login name on the local host. - Otherwise, LPD refuses the job. - - This capability is particularly useful in an environment - where there are (for example) different departments sharing a - network, and some users transcend departmental boundaries. By - giving them accounts on your systems, they can use your - printers from their own departmental systems. If you would - rather allow them to use only your - printers and not your compute resources, you can give them - “token” accounts, with no home directory and a - useless shell like /usr/bin/false. + Replace the job name on the header page with + text. The job name is normally the + name of the first file of the job, or + stdin if you are printing standard + input. + + + + + -h + + + Do not print any header page. + + + At some sites, this option may have no effect due to the + way header pages are generated. See Header + Pages for details. + - - Accounting for Printer Usage - - So, you need to charge for printouts. And why not? Paper and ink - cost money. And then there are maintenance costs—printers are - loaded with moving parts and tend to break down. You have examined - your printers, usage patterns, and maintenance fees and have come up - with a per-page (or per-foot, per-meter, or per-whatever) cost. Now, - how do you actually start accounting for printouts? - - Well, the bad news is the LPD spooling system does not provide - much help in this department. Accounting is highly dependent on the - kind of printer in use, the formats being printed, and - your requirements in charging for printer - usage. + + Administrating Printers - To implement accounting, you have to modify a printer's text - filter (to charge for plain text jobs) and the conversion filters (to - charge for other file formats), to count pages or query the printer - for pages printed. You cannot get away with using the simple output - filter, since it cannot do accounting. See section Filters. - - Generally, there are two ways to do accounting: + As an administrator for your printers, you have had to install, + set up, and test them. Using the &man.lpc.8; command, you + can interact with your printers in yet more ways. With &man.lpc.8;, + you can - Periodic accounting is the more common - way, possibly because it is easier. Whenever someone prints a - job, the filter logs the user, host, and number of pages to an - accounting file. Every month, semester, year, or whatever time - period you prefer, you collect the accounting files for the - various printers, tally up the pages printed by users, and charge - for usage. Then you truncate all the logging files, starting with - a clean slate for the next period. + Start and stop the printers - + + + Enable and disable their queues + + - Timely accounting is less common, - probably because it is more difficult. This method has the - filters charge users for printouts as soon as they use the - printers. Like disk quotas, the accounting is immediate. You can - prevent users from printing when their account goes in the red, - and might provide a way for users to check and adjust their - “print quotas.” But this method requires some database - code to track users and their quotas. + Rearrange the order of the jobs in each queue. - The LPD spooling system supports both methods easily: since you - have to provide the filters (well, most of the time), you also have to - provide the accounting code. But there is a bright side: you have - enormous flexibility in your accounting methods. For example, you - choose whether to use periodic or timely accounting. You choose what - information to log: user names, host names, job types, pages printed, - square footage of paper used, how long the job took to print, and so - forth. And you do so by modifying the filters to save this - information. + First, a note about terminology: if a printer is + stopped, it will not print anything in its queue. + Users can still submit jobs, which will wait in the queue until the + printer is started or the queue is + cleared. - - Quick and Dirty Printer Accounting - - FreeBSD comes with two programs that can get you set up with - simple periodic accounting right away. They are the text filter - lpf, described in section lpf: a Text Filter, and - &man.pac.8;, a program to gather and total - entries from printer accounting files. - - As mentioned in the section on filters (Filters), LPD starts - the text and the conversion filters with the name of the accounting - file to use on the filter command line. The filters can use this - argument to know where to write an accounting file entry. The name - of this file comes from the af capability in - /etc/printcap, and if not specified as an - absolute path, is relative to the spooling directory. - - LPD starts lpf with page width and length - arguments (from the pw and pl - capabilities). lpf uses these arguments to - determine how much paper will be used. After sending the file to - the printer, it then writes an accounting entry in the accounting - file. The entries look like this: - - -2.00 rose:andy -3.00 rose:kelly -3.00 orchid:mary -5.00 orchid:mary -2.00 orchid:zhang - - You should use a separate accounting file for each printer, as - lpf has no file locking logic built into it, and - two lpfs might corrupt each other's entries if - they were to write to the same file at the same time. A easy way to - insure a separate accounting file for each printer is to use - af=acct in /etc/printcap. - Then, each accounting file will be in the spooling directory for a - printer, in a file named acct. - - When you are ready to charge users for printouts, run the - &man.pac.8; program. Just change to the spooling directory for - the printer you want to collect on and type pac. - You will get a dollar-centric summary like the following: - - Login pages/feet runs price -orchid:kelly 5.00 1 $ 0.10 -orchid:mary 31.00 3 $ 0.62 -orchid:zhang 9.00 1 $ 0.18 -rose:andy 2.00 1 $ 0.04 -rose:kelly 177.00 104 $ 3.54 -rose:mary 87.00 32 $ 1.74 -rose:root 26.00 12 $ 0.52 + If a queue is disabled, no user (except root) + can submit jobs for the printer. An enabled + queue allows jobs to be submitted. A printer can be + started for a disabled queue, in which case it + will continue to print jobs in the queue until the queue is + empty. + + In general, you have to have root privileges to use the + &man.lpc.8; command. Ordinary users can use the &man.lpc.8; command + to get printer status and to restart a hung printer only. -total 337.00 154 $ 6.74 - - These are the arguments &man.pac.8; expects: + Here is a summary of the &man.lpc.8; commands. Most of the + commands takes a printer-name argument to + tell on which printer to operate. You can use all + for the printer-name to mean all printers + listed in /etc/printcap. + + + + abort + printer-name + + + Cancel the current job and stop the printer. Users can + still submit jobs if the queue's enabled. + + + + + clean + printer-name + + + Remove old files from the printer's spooling directory. + Occasionally, the files that make up a job are not properly + removed by LPD, particularly if there have been errors during + printing or a lot of administrative activity. This command + finds files that do not belong in the spooling directory and + removes them. + + + + + disable + printer-name + + + Disable queuing of new jobs. If the printer's started, it + will continue to print any jobs remaining in the queue. The + superuser (root) can always submit jobs, even to a disabled + queue. + + This command is useful while you are testing a new printer + or filter installation: disable the queue and submit jobs as + root. Other users will not be able to submit jobs until you + complete your testing and re-enable the queue with the + enable command. + + + + + down printer-name + message + + + Take a printer down. Equivalent to + disable followed by stop. + The message appears as the printer's + status whenever a user checks the printer's queue with + &man.lpq.1; or status with lpc + status. + + + + + enable + printer-name + + + Enable the queue for a printer. Users can submit jobs but + the printer will not print anything until it is started. + + - - - + + help + command-name + + + Print help on the command + command-name. With no + command-name, print a summary of the + commands available. + + - - Which printer to summarize. - This option works only if there is an absolute path in the - af capability in - /etc/printcap. - - - - - - - - Sort the output by cost instead of alphabetically by user - name. - - - - - - - - Ignore host name in the accounting files. With this - option, user smith on host - alpha is the same user - smith on host gamma. - Without, they are different users. - - - - - - - - Compute charges with price - dollars per page or per foot instead of the price from the - pc capability in - /etc/printcap, or two cents (the - default). You can specify price as - a floating point number. - - - - - - - - Reverse the sort order. - - - - - - - - Make an accounting summary file and truncate the - accounting file. - - + + restart + printer-name - - name - … - - - Print accounting information for the given user - names only. - - - + + Start the printer. Ordinary users can use this command if + some extraordinary circumstance hangs LPD, but they cannot start + a printer stopped with either the stop or + down commands. The + restart command is equivalent to + abort followed by + start. + + - In the default summary that &man.pac.8; produces, you see the - number of pages printed by each user from various hosts. If, at - your site, host does not matter (because users can use any host), - run pac -m, to produce the following - summary: - - Login pages/feet runs price -andy 2.00 1 $ 0.04 -kelly 182.00 105 $ 3.64 -mary 118.00 35 $ 2.36 -root 26.00 12 $ 0.52 -zhang 9.00 1 $ 0.18 + + start + printer-name + + + Start the printer. The printer will print jobs in its + queue. + + -total 337.00 154 $ 6.74 - + + stop + printer-name + + + Stop the printer. The printer will finish the current job + and will not print anything else in its queue. Even though the + printer is stopped, users can still submit jobs to an enabled + queue. + + - To compute the dollar amount due, - &man.pac.8; uses the pc capability in the - /etc/printcap file (default of 200, or 2 cents - per page). Specify, in hundredths of cents, the price per page or - per foot you want to charge for printouts in this capability. You - can override this value when you run &man.pac.8; with the - option. The units for the - option are in dollars, though, not hundredths of cents. For - example, - - &prompt.root; pac -p1.50 - - makes each page cost one dollar and fifty cents. You can really - rake in the profits by using this option. - - Finally, running pac -s will save the summary - information in a summary accounting file, which is named the same as - the printer's accounting file, but with _sum - appended to the name. It then truncates the accounting file. When - you run &man.pac.8; again, it rereads the - summary file to get starting totals, then adds information from the - regular accounting file. - - - - How Can You Count Pages Printed? + + topq printer-name + job-or-username + + + Rearrange the queue for + printer-name by placing the jobs with + the listed job numbers or the jobs + belonging to username at the top of + the queue. For this command, you cannot use + all as the + printer-name. + + - In order to perform even remotely accurate accounting, you need - to be able to determine how much paper a job uses. This is the - essential problem of printer accounting. - - For plain text jobs, the problem's not that hard to solve: you - count how many lines are in a job and compare it to how many lines - per page your printer supports. Do not forget to take into account - backspaces in the file which overprint lines, or long logical lines - that wrap onto one or more additional physical lines. - - The text filter lpf (introduced in lpf: a Text Filter) takes - into account these things when it does accounting. If you are - writing a text filter which needs to do accounting, you might want - to examine lpf's source code. - - How do you handle other file formats, though? - - Well, for DVI-to-LaserJet or DVI-to-PostScript conversion, you - can have your filter parse the diagnostic output of - dvilj or dvips and look to see - how many pages were converted. You might be able to do similar - things with other file formats and conversion programs. - - But these methods suffer from the fact that the printer may not - actually print all those pages. For example, it could jam, run out - of toner, or explode—and the user would still get - charged. - - So, what can you do? - - There is only one sure way to do - accurate accounting. Get a printer that can - tell you how much paper it uses, and attach it via a serial line or - a network connection. Nearly all PostScript printers support this - notion. Other makes and models do as well (networked Imagen laser - printers, for example). Modify the filters for these printers to - get the page usage after they print each job and have them log - accounting information based on that value - only. There is no line counting nor - error-prone file examination required. - - Of course, you can always be generous and make all printouts - free. - + + up + printer-name + + + Bring a printer up; the opposite of the + down command. Equivalent to + start followed by + enable. + + + + + &man.lpc.8; accepts the above commands on the command line. If + you do not enter any commands, &man.lpc.8; enters an interactive mode, + where you can enter commands until you type exit, + quit, or end-of-file. Alternatives to the Standard Spooler If you have been reading straight through this manual, by now you have learned just about everything there is to know about the LPD spooling system that comes with FreeBSD. You can probably appreciate many of its shortcomings, which naturally leads to the question: “What other spooling systems are out there (and work with FreeBSD)?” Unfortunately, I have located only two alternatives—and they are almost identical to each other! They are: PLP, the Portable Line Printer Spooler System PLP was based on software developed by Patrick Powell and then maintained by an Internet-wide group of developers. The main site for the software is at ftp://ftp.iona.ie/pub/plp/. There is also a web page. It is quite similar to the BSD LPD spooler, but boasts a host of features, including: Better network support, including built-in support for networked printers, NIS-maintained printcaps, and NFS-mounted spooling directories Sophisticated queue management, allowing multiple printers on a queue, transfer of jobs between queues, and queue redirection Remote printer control functions Prioritization of jobs Expansive security and access options LPRng LPRng, which purportedly means “LPR: the Next Generation” is a complete rewrite of PLP. Patrick Powell and Justin Mason (the principal maintainer of PLP) collaborated to make LPRng. The main site for LPRng is ftp://dickory.sdsu.edu/pub/LPRng/. - - - Acknowledgments - - I would like to thank the following people who have assisted in the - development of this document: + + + Troubleshooting + + After performing the simple test with &man.lptest.1;, you might + have gotten one of the following results instead of the correct + printout: - Daniel Eischen - deischen@iworks.interworks.org + It worked, after awhile; or, it did not eject a full + sheet. - For providing a plethora of HP filter programs for - perusal. + The printer printed the above, but it sat for awhile and + did nothing. In fact, you might have needed to press a + PRINT REMAINING or FORM FEED button on the printer to get any + results to appear. + + If this is the case, the printer was probably waiting to + see if there was any more data for your job before it printed + anything. To fix this problem, you can have the text filter + send a FORM FEED character (or whatever is necessary) to the + printer. This is usually sufficient to have the printer + immediately print any text remaining in its internal buffer. + It is also useful to make sure each print job ends on a full + sheet, so the next job does not start somewhere on the middle + of the last page of the previous job. + + The following replacement for the shell script + /usr/local/libexec/if-simple prints a + form feed after it sends the job to the printer: + + +#!/bin/sh +# +# if-simple - Simple text input filter for lpd +# Installed in /usr/local/libexec/if-simple +# +# Simply copies stdin to stdout. Ignores all filter arguments. +# Writes a form feed character (\f) after printing job. + +/bin/cat && printf "\f" && exit 0 +exit 2 - + + + It produced the “staircase effect.” + + + You got the following on paper: + + +!"#$%&'()*+,-./01234 + "#$%&'()*+,-./012345 + #$%&'()*+,-./0123456 + + You have become another victim of the staircase + effect, caused by conflicting interpretations of + what characters should indicate a new line. UNIX-style + operating systems use a single character: ASCII code 10, the + line feed (LF). MS-DOS, OS/2, and others uses a pair of + characters, ASCII code 10 and ASCII code + 13 (the carriage return or CR). Many printers use the MS-DOS + convention for representing new-lines. + + When you print with FreeBSD, your text used just the line + feed character. The printer, upon seeing a line feed + character, advanced the paper one line, but maintained the + same horizontal position on the page for the next character + to print. That is what the carriage return is for: to move + the location of the next character to print to the left edge + of the paper. + + Here is what FreeBSD wants your printer to do: + + + + + + Printer received CR + Printer prints CR + + + + Printer received LF + Printer prints CR + LF + + + + + + Here are some ways to achieve this: + + + + Use the printer's configuration switches or control + panel to alter its interpretation of these characters. + Check your printer's manual to find out how to do + this. + + + If you boot your system into other operating systems + besides FreeBSD, you may have to + reconfigure the printer to use a an + interpretation for CR and LF characters that those other + operating systems use. You might prefer one of the other + solutions, below. + + + + + Have FreeBSD's serial line driver automatically + convert LF to CR+LF. Of course, this works with printers + on serial ports only. To enable this + feature, set the CRMOD bit in fs + capability in the /etc/printcap file + for the printer. + + + + Send an escape code to the + printer to have it temporarily treat LF characters + differently. Consult your printer's manual for escape + codes that your printer might support. When you find the + proper escape code, modify the text filter to send the + code first, then send the print job. + + Here is an example text filter for printers that + understand the Hewlett-Packard PCL escape codes. This + filter makes the printer treat LF characters as a LF and + CR; then it sends the job; then it sends a form feed to + eject the last page of the job. It should work with + nearly all Hewlett Packard printers. + + +#!/bin/sh +# +# hpif - Simple text input filter for lpd for HP-PCL based printers +# Installed in /usr/local/libexec/hpif +# +# Simply copies stdin to stdout. Ignores all filter arguments. +# Tells printer to treat LF as CR+LF. Ejects the page when done. + +printf "\033&k2G" && cat && printf "\033&l0H" && exit 0 +exit 2 + + Here is an example /etc/printcap + from a host called orchid. It has a single printer + attached to its first parallel port, a Hewlett Packard + LaserJet 3Si named teak. It is using the + above script as its text filter: + + +# +# /etc/printcap for host orchid +# +teak|hp|laserjet|Hewlett Packard LaserJet 3Si:\ + :lp=/dev/lpt0:sh:sd=/var/spool/lpd/teak:mx#0:\ + :if=/usr/local/libexec/hpif: + + + + + - &a.jehamby; + It overprinted each line. - For the Ghostscript-to-HP filter. + The printer never advanced a line. All of the lines of + text were printed on top of each other on one line. + + This problem is the “opposite” of the + staircase effect, described above, and is much rarer. + Somewhere, the LF characters that FreeBSD uses to end a line + are being treated as CR characters to return the print + location to the left edge of the paper, but not also down a + line. + + Use the printer's configuration switches or control panel + to enforce the following interpretation of LF and CR + characters: + + + + + + Printer receives + Printer prints + + + + + + CR + CR + + + + LF + CR + LF + + + + - &a.jfieber; + The printer lost characters. - For debugging why printing from Windows 95 to a FreeBSD - system simulating a PostScript printer with Ghostscript didn't - produce correct output, and suggesting a fix, which is included - herein. + While printing, the printer did not print a few characters + in each line. The problem might have gotten worse as the + printer ran, losing more and more characters. + + The problem is that the printer cannot keep up with the + speed at which the computer sends data over a serial line + (this problem should not occur with printers on parallel + ports). There are two ways to overcome the problem: + + + + If the printer supports XON/XOFF flow control, have + FreeBSD use it by specifying the TANDEM bit in the + fs capability. + + + + If the printer supports carrier flow control, specify + the MDMBUF bit in the fs capability. + Make sure the cable connecting the printer to the computer + is correctly wired for carrier flow control. + + + + If the printer does not support any flow control, use + some combination of the NLDELAY, TBDELAY, CRDELAY, VTDELAY, + and BSDELAY bits in the fs capability + to add appropriate delays to the stream of data sent to + the printer. + + - Stephen Montgomery-Smith - stephen@math.missouri.edu + It printed garbage. - For suggesting using "\033&l0H" instead of "\f" to eject - the last page on HP printers; the latter could eject an extra - blank page while the former never does. + The printer printed what appeared to be random garbage, + but not the desired text. + + This is usually another symptom of incorrect + communications parameters with a serial printer. Double-check + the bps rate in the br capability, and the + parity bits in the fs and + fc capabilities; make sure the printer is + using the same settings as specified in the + /etc/printcap file. - + - My wife, Mary Kelly - urquhart@argyre.colorado.edu + Nothing happened. - For allowing me to spend more time with FreeBSD than - with her. + If nothing happened, the problem is probably within + FreeBSD and not the hardware. Add the log file + (lf) capability to the entry for the + printer you are debugging in the + /etc/printcap file. For example, here is + the entry for rattan, with the + lf capability: + + +rattan|line|diablo|lp|Diablo 630 Line Printer:\ + :sh:sd=/var/spool/lpd/rattan:\ + :lp=/dev/lpt0:\ + :if=/usr/local/libexec/if-simple:\ + :lf=/var/log/rattan.log + + Then, try printing again. Check the log file (in our + example, /var/log/rattan.log) to see any + error messages that might appear. Based on the messages you + see, try to correct the problem. + + If you do not specify a lf capability, + LPD uses /dev/console as a + default.