diff --git a/en_US.ISO8859-1/books/handbook/printing/chapter.sgml b/en_US.ISO8859-1/books/handbook/printing/chapter.sgml index 85b7dd3ef6..f59c32487f 100644 --- a/en_US.ISO8859-1/books/handbook/printing/chapter.sgml +++ b/en_US.ISO8859-1/books/handbook/printing/chapter.sgml @@ -1,4872 +1,4860 @@ Sean Kelly Contributed by Jim Mock Restructured and updated by Printing Synopsis LPD spooling system printing &os; can be used to print with a wide variety of printers, from the oldest impact printer to the latest laser printers, and everything in between, allowing you to produce high-quality printed output from the applications you run. &os; can also be configured to act as a print server on a network; in this capacity &os; can receive print jobs from a variety - of other computers, including other &os; computers, &windows; and &macos; - hosts. &os; will ensure that one job at a time is printed, and can - keep statistics on which users and machines are doing the most printing, - produce banner pages showing who's printout is who's, and - more. + of other computers, including other &os; computers, &windows; and + &macos; hosts. &os; will ensure that one job at a time is printed, and + can keep statistics on which users and machines are doing the most + printing, produce banner pages showing who's printout is + who's, and more. After reading this chapter, you will know: How to configure the &os; print spooler. How to install print filters, to handle special print jobs differently, including converting incoming documents to print formats that your printers understand. How to enable header, or banner pages on your printout. How to print with printers connected to other computers. How to print with printers connected directly to the network. How to control printer restrictions, including limiting the size of print jobs, and preventing certain users from printing. How to keep printer statistics, and account for printer usage. How to troubleshoot printing problems. Before reading this chapter, you should: - Know how to configure and install a new kernel + Know how to configure and install a new kernel (). Introduction In order to use printers with &os; you may set them up to work with the Berkeley line printer spooling system, also known as the LPD spooling system, or just LPD. It is the standard printer control system in &os;. This chapter introduces LPD and will guide you through its configuration. - If you are already familiar with + If you are already familiar with LPD or another printer spooling system, you may wish to skip to section Basic Setup. + linkend="printing-intro-setup">Basic Setup. - LPD controls everything about a + 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. print jobs 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 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 takes care of communications parameters for printers connected on serial ports. - It can send jobs over the network to a + It can send jobs over the network to a 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 (/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. + 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 + 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. + you do not have to wait for data to be copied to the + printer. &tex; - 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 + 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. 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: + 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 - communicate with it, and print plain text files to the - printer. + 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 learn 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. + See section Advanced Printer + Setup to learn 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. + 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 set up the + Setup shows how to set up 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 computer's local interfaces, see Printers With Networked Data Stream Interfaces. 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. + 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 &os; 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. + linkend="printing-software">Software Setup. Ports and Cables Printers sold for use on PC's today generally come with one or more of the following three interfaces: - printers - serial - + printers + serial + Serial interfaces, also known as RS-232 or COM ports, 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. Most PC serial ports have a maximum - transmission rate of 115200 bps, which makes printing - large graphic print jobs with them impractical. + transmission rate of 115200 bps, which makes printing + large graphic print jobs with them impractical. - printers - parallel - + printers + parallel + Parallel interfaces use a parallel port on your computer to send data to the printer. Parallel interfaces are common in the PC market and are faster than RS-232 serial. 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. - centronics + centronics parallel printers Parallel interfaces are sometimes known as Centronics interfaces, named after the connector type on the printer. - printers - USB - + printers + USB + USB interfaces, named for the Universal Serial - Bus, can run at even faster speeds than parallel or - RS-232 serial interfaces. Cables are simple and cheap. - USB is superior to RS-232 Serial and to Parallel for - printing, but it is not as well supported under &unix; - systems. A way to avoid this problem is to purchase a - printer that has both a USB interface and a Parallel - interface, as many printers do. + Bus, can run at even faster speeds than parallel or + RS-232 serial interfaces. Cables are simple and cheap. + USB is superior to RS-232 Serial and to Parallel for + printing, but it is not as well supported under &unix; + systems. A way to avoid this problem is to purchase a + printer that has both a USB interface and a Parallel + interface, as many printers do. In general, Parallel interfaces usually offer just one-way communication (computer to printer) while serial - and USB gives you two-way. Newer parallel ports (EPP and - ECP) and printers - can communicate in both directions under &os; when a - IEEE-1284-compliant cable is used. + and USB gives you two-way. Newer parallel ports (EPP and + ECP) and printers can communicate in both directions under &os; + when a IEEE-1284-compliant cable is used. PostScript Two-way communication to the printer over a parallel port is generally done in one of two ways. The first method uses a custom-built printer driver for &os; that speaks the proprietary language used by the printer. This is common with inkjet printers and can be used for reporting ink levels and other status information. The second method is used when the printer supports &postscript;. - &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 + &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 to the user. - + 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 ppc0 to - &os;; the second is ppc1, and so - on. The printer device name uses the same scheme: - /dev/lpt0 for the printer on the first - parallel ports etc. + The first parallel port is + ppc0 to &os;; the second + is ppc1, and so on. The + printer device name uses the same scheme: + /dev/lpt0 for the printer + on the first parallel ports etc. Serial Ports 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. 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. null-modem 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. baud rate parity flow control protocol 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) 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 + 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 &os;. 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 + linkend="printing-kernel">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 + linkend="printing-parallel-port-mode">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. You will find out how - to do this later in this chapter. + 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. To find out if the kernel you are currently using supports a serial interface, type: &prompt.root; grep sioN /var/run/dmesg.boot Where N is the number of the serial port, starting from zero. If you see output similar to the following: sio2 at port 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: &prompt.root; grep ppcN /var/run/dmesg.boot Where N is the number of the parallel port, starting from zero. If you see output similar to the following: - - ppc0: <Parallel port> at port 0x378-0x37f irq 7 on isa0 + + ppc0: <Parallel port> at port 0x378-0x37f irq 7 on isa0 ppc0: SMC-like chipset (ECP/EPP/PS2/NIBBLE) in COMPATIBLE mode ppc0: FIFO with 16/16/8 bytes threshold - - then the kernel supports the port. + + 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. - - Setting the Communication Mode for the Parallel - Port - When you are using the parallel interface, you can choose - whether &os; should use interrupt-driven or polled - communication with the printer. The generic printer - device driver (&man.lpt.4;) on &os; - uses the &man.ppbus.4; system, which controls the port - chipset with the &man.ppc.4; driver. + + Setting the Communication Mode for the Parallel + Port - - - 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. - + When you are using the parallel interface, you can choose + whether &os; should use interrupt-driven or polled + communication with the printer. The generic printer + device driver (&man.lpt.4;) on &os; + uses the &man.ppbus.4; system, which controls the port + chipset with the &man.ppc.4; driver. - - 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. - - + + + 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 usually somewhat faster - but uses up a precious IRQ line. Some newer HP printers - are claimed not to work correctly in interrupt mode, - apparently due to some (not yet exactly understood) timing - problem. These printers need polled mode. You should use - whichever one works. Some printers will work in both - modes, but are painfully slow in interrupt mode. + + 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. + + - You can set the communications mode in two ways: by - configuring the kernel or by using the &man.lptcontrol.8; - program. + The interrupt-driven method is usually somewhat faster + but uses up a precious IRQ line. Some newer HP printers + are claimed not to work correctly in interrupt mode, + apparently due to some (not yet exactly understood) timing + problem. These printers need polled mode. You should use + whichever one works. Some printers will work in both + modes, but are painfully slow in interrupt mode. - To set the communications mode by configuring - the kernel: + You can set the communications mode in two ways: by + configuring the kernel or by using the &man.lptcontrol.8; + program. - - - Edit your kernel configuration file. Look for - an ppc0 entry. If you are setting up - the second parallel port, use ppc1 - instead. Use ppc2 for the third port, - and so on. + To set the communications mode by configuring + the kernel: - - - If you want interrupt-driven mode, edit the following line: + + + Edit your kernel configuration file. Look for + an ppc0 entry. If you are setting up + the second parallel port, use ppc1 + instead. Use ppc2 for the third port, + and so on. - hint.ppc.0.irq="N" + + + If you want interrupt-driven mode, edit the following + line: - in the /boot/device.hints file - and replace N with the right - IRQ number. The kernel configuration file must - also contain the &man.ppc.4; driver: + hint.ppc.0.irq="N" - device ppc + in the /boot/device.hints file + and replace N with the right + IRQ number. The kernel configuration file must + also contain the &man.ppc.4; driver: - + device ppc + - - If you want polled mode, remove in your - /boot/device.hints file, the - following line: - - hint.ppc.0.irq="N" - - In some cases, this is not enough to put the - port in polled mode under &os;. Most of - time it comes from &man.acpi.4; driver, this latter - is able to probe and attach devices, and therefore, - control the access mode to the printer port. You - should check your &man.acpi.4; configuration to - correct this problem. - - - + + If you want polled mode, remove in your + /boot/device.hints file, the + following line: + + hint.ppc.0.irq="N" + + In some cases, this is not enough to put the + port in polled mode under &os;. Most of + time it comes from &man.acpi.4; driver, this latter + is able to probe and attach devices, and therefore, + control the access mode to the printer port. You + should check your &man.acpi.4; configuration to + correct this problem. + + + - - Save the file. Then configure, build, and install the - kernel, then reboot. See kernel configuration for - more details. - - + + Save the file. Then configure, build, and install the + kernel, then reboot. See kernel + configuration for more details. + + - To set the communications mode with - &man.lptcontrol.8;: + To set the communications mode with + &man.lptcontrol.8;: - - - Type: + + + Type: - &prompt.root; lptcontrol /dev/lptN + &prompt.root; lptcontrol /dev/lptN - to set interrupt-driven mode for - lptN. - + to set interrupt-driven mode for + lptN. + - - Type: + + Type: - &prompt.root; lptcontrol /dev/lptN + &prompt.root; lptcontrol /dev/lptN - to set polled-mode for + 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 - information. - + 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 + information. + - - Checking Printer Communications + + 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. + 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. - PostScript - 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: + PostScript + 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 + %!PS 100 100 moveto 300 300 lineto stroke 310 310 moveto /Helvetica findfont 12 scalefont setfont (Is this thing working?) show showpage - The above &postscript; code can be placed into a file and - used as shown in the examples appearing in the following - sections. + The above &postscript; code can be placed into a file and + used as shown in the examples appearing in the following + sections. - PCL - - 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. - + PCL + + 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 + + Checking a Parallel Printer - - printers - parallel - - This section tells you how to check if &os; can - communicate with a printer connected to a parallel - port. + + printers + parallel + + This section tells you how to check if &os; can + communicate with a printer connected to a parallel + port. - To test a printer on a parallel - port: + To test a printer on a parallel + port: - - - Become root with &man.su.1;. - + + + Become root with &man.su.1;. + - - Send data to the printer. + + Send data to the printer. - - - If the printer can print plain text, then use - &man.lptest.1;. Type: + + + If the printer can print plain text, then use + &man.lptest.1;. Type: - &prompt.root; lptest > /dev/lptN + &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: + + If the printer understands &postscript; or other + printer language, then send a small program to the + printer. Type: - &prompt.root; cat > /dev/lptN + &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. + 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: + Alternatively, you can put the program in a file + and type: - &prompt.root; cat file > /dev/lptN + &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 + + Checking a Serial Printer - - printers - serial - - This section tells you how to check if &os; can - communicate with a printer on a serial port. - - To test a printer on a serial - port: - - - - Become root with &man.su.1;. - - - - Edit the file /etc/remote. Add - the following entry: - - printer:dv=/dev/port:br#bps-rate:pa=parity - - bits-per-second - serial port - 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, - 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: - - printer:dv=/dev/ttyd2:br#19200:pa=none - - - - 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: - - &prompt.user; $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: - - &prompt.user; >file - - 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. - - + + printers + serial + + This section tells you how to check if &os; can + communicate with a printer on a serial port. + + To test a printer on a serial + port: + + + + Become root with &man.su.1;. + + + + Edit the file /etc/remote. Add + the following entry: + + printer:dv=/dev/port:br#bps-rate:pa=parity + + bits-per-second + serial port + 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, + 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: + + printer:dv=/dev/ttyd2:br#19200:pa=none + + + + 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: + + &prompt.user; $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: + + &prompt.user; >file + + 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. + + 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. You configure LPD by editing the file - /etc/printcap. The + /etc/printcap. The LPD spooling system reads this file each time the spooler is used, so updates to the file take immediate effect. - printers - capabilities - + printers + capabilities + 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;. 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 the + /etc/printcap file; see the Naming the Printer section for more information on naming. 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 the Making the Spooling - Directory section for more information. + linkend="printing-spooldir">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 the Identifying the Printer - Device for more information. Also, if the printer is + Set the /dev entry + to use for the 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 ms# capability which is discussed in the Configuring Spooler + the ms# capability which is discussed in the + Configuring Spooler Communications Parameters section. Install a plain text input filter; see the Installing the Text - Filter section for details. + linkend="printing-textfilter">Installing the Text + Filter section for details. Test the setup by printing something with the &man.lpr.1; command. More details are available in the Trying It Out and - Troubleshooting + 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. 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 + linkend="printing-advanced-if-conversion">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 of 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, + 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. 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 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 ps, PS, S, panasonic, and Panasonic KX-P4455 PostScript v51.4. Suppressing Header Pages - printing - header pages - + printing + header pages + - The LPD spooling system will + 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. To suppress header pages, add the sh capability to the entry for the printer in /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. Every line in an entry except the last ends in a backslash character. Making the Spooling Directory printer spool print jobs 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. + /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 + 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: + 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: # # /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 and each line end 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. + /var/spool/lpd as a + default. Identifying the Printer Device In the Hardware Setup section, we identified the port and the relevant /dev directory entry that - &os; will use to communicate with the printer. Now, we tell + &os; 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). - List the /dev entry pathname in the - /etc/printcap file using the + 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: # # /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. - /dev/lp currently does not exist in - &os;. + LPD uses + /dev/lp as a default. + /dev/lp currently does + not exist in &os;. 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 + linkend="printing-textfilter">Installing the Text + Filter. Otherwise, be sure to follow the instructions in the next section. Configuring Spooler Communication Parameters - printers - serial - + printers + serial + 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 - advantageous since: + 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 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. It enables the spooling system to use the same filter 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: 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, 38400, 57600, or 115200 bits-per-second. ms#stty-mode Sets the options for the terminal device after opening the device. &man.stty.1; explains the available options. When LPD opens the device specified by the lp capability, it sets the characteristics of the device to those specified with the ms# capability. Of particular interest will be the parenb, parodd, cs5, cs6, cs7, cs8, cstopb, crtscts, and ixon modes, which are explained in the &man.stty.1; manual page. Let us add to our example printer on the sixth serial port. We will set the bps rate to 38400. For the mode, we will set no parity with -parenb, 8-bit characters with cs8, no modem control with clocal and hardware flow control with crtscts: bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4:\ :sh:sd=/var/spool/lpd/bamboo:\ :lp=/dev/ttyd5:ms#-parenb cs8 clocal crtscts: Installing the Text Filter printing filters 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 + 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. &os; 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. + linkend="printing-advanced-lpf">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: #!/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:\ + :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:ms#-parenb cs8 clocal crtscts:\ :if=/usr/local/libexec/if-simple: A copy of the if-simple script can be found in the /usr/share/examples/printing directory. Turn on <application>LPD</application> &man.lpd.8; is run from /etc/rc, controlled by the lpd_enable variable. This variable defaults to NO. If you have not done so already, add the line: lpd_enable="YES" to /etc/rc.conf, and then either restart your machine, or just run &man.lpd.8;. &prompt.root; lpd - + Trying It Out - You have reached the end of the simple + 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 + 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. + linkend="printing-testing">Checking Printer + Communications to generate some test text. To test the simple LPD setup: Type: &prompt.root; lptest 20 5 | lpr printer-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 + 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 Troubleshooting + linkend="printing-troubleshooting">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. Filters printing 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). - + 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. - + 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, &os; 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 &os; - Ports Collection. - + /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 &os; + 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 + + 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 for each of your printers. - - - - LPD expects every printer to be + and debug problems you might encounter as you install more and + more filters for each of your printers. + + + + LPD expects every printer to be able to print plain text by - default. This presents a problem for &postscript; printers (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. You should read this - section if you have a &postscript; printer. - - - - &postscript; is a popular output format for many programs. - Some people even write &postscript; code directly. Unfortunately, - &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. You should read - 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 to print troff data, or - lpr to print &tex; DVI data, or lpr - to print raster image data, and so forth. The - reading of this section is recommended. - - - - Section Output - Filters tells all about a not often used feature of + default. This presents a problem for &postscript; printers + (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. You should read this + section if you have a &postscript; printer. + + + + &postscript; is a popular output format for many programs. + Some people even write &postscript; code directly. Unfortunately, + &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. You + should read 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 to + print troff data, or lpr + to print &tex; DVI data, or + lpr to print raster image + data, and so forth. The reading of this section is + recommended. + + + + 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 &os;. 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. - + 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 &os;. 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. + - + A copy of the various scripts described below can be found in the /usr/share/examples/printing directory. - 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). - - - troff - - 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 , 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 + 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). + + + troff + + 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 , + 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. + 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 - -w width - -l length - -i indent - -n login - -h host - acct-file - - - where - - - - - - - appears if the job is submitted with lpr - - - - - - 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 - , 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. - - - - + 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 + -w width + -l length + -i indent + -n login + -h host + acct-file + + + where + + + + + + + appears if the job is submitted with lpr + + + + + + 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 + , 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. + + + + - printing - filters - - - 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 - -x pixel-width - -y pixel-height - -n login - -h host - acct-file - + printing + filters + + + 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 + -x pixel-width + -y pixel-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 our - experience, output filters are rarely used. Section Output Filters describes - them. There are only two arguments to an output filter: - - - filter-name - -w width - -l length - - - 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 + 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 our + experience, output filters are rarely used. Section Output Filters describes + them. There are only two arguments to an output filter: + + + filter-name + -w width + -l length + + + 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 + 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. + + + + + 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 &os; 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. + + + + + The text filter that comes with the &os; 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 - print jobs - - 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? - - - printers - serial - - 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 &os; Ports Collection - (see The Ports Collection). You can - install one of the both print/lprps-a4 and print/lprps-letter ports according to the paper size used. 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: + Accommodating Plain Text Jobs on &postscript; Printers + print jobs + + 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? + + + printers + serial + + 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 &os; Ports Collection + (see The Ports Collection). You can + install one of the both + print/lprps-a4 and + print/lprps-letter ports + according to the paper size used. 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: The rw capability should be also included in order to let LPD to open the printer in the 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 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 # IFS="" read -r 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 &os; Ports - Collection (see The Ports Collection) - includes a full featured text-to-&postscript; program called - a2ps that you might want to investigate. + + 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 &os; 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 - emulating - - - Ghostscript - &postscript; is the de facto standard for - high quality typesetting and printing. &postscript; is, however, an - expensive standard. Thankfully, Aladdin - Enterprises has a free &postscript; work-alike called - Ghostscript that runs with &os;. - 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 is in the &os; Ports Collection, - many versions are available, the most commonly used version - is print/ghostscript-gpl. - - 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 - to get a list of devices the current installation of - Ghostscript supports.) - - #!/bin/sh + Simulating &postscript; on Non &postscript; Printers + + PostScript + emulating + + Ghostscript + + &postscript; is the de facto standard for + high quality typesetting and printing. &postscript; is, however, an + expensive standard. Thankfully, Aladdin + Enterprises has a free &postscript; work-alike called + Ghostscript that runs with &os;. + 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 is in the &os; Ports + Collection, many versions are available, the most commonly used + version is print/ghostscript-gpl. + + 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 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/ifhp # # Treat LF as CR+LF (to avoid the "staircase effect" on HP/PCL # printers): # printf "\033&k2G" || exit 2 # # Read first two characters of the file # IFS="" read -r first_line first_two_chars=`expr "$first_line" : '\(..\)'` if [ "$first_two_chars" = "%!" ]; then # # It is PostScript; use Ghostscript to scan-convert and print it. # /usr/local/bin/gs -dSAFER -dNOPAUSE -q -sDEVICE=djet500 \ -sOutputFile=- - && exit 0 else # # Plain text or HP/PCL, so just print it directly; print a form feed # at the end to eject the last page. # - echo "$first_line" && cat && printf "\033&l0H" && + echo "$first_line" && cat && printf "\033&l0H" && exit 0 fi exit 2 - Finally, you need to notify LPD of + Finally, you need to notify LPD of the filter via the if capability: - - :if=/usr/local/libexec/ifhp: - That is it. You can type lpr plain.text and - lpr whatever.ps and both should print - successfully. + :if=/usr/local/libexec/ifhp: + + 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? - - &tex; - printing DVI files - - - 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 + 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? + + &tex; + printing DVI files + + + 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 seaweed-analysis.dvi - - We got LPD to do the DVI file + + 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 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 Conversion 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 + 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 Conversion 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 - tf - - - - - raster - vf - - - - - plain text - if - none, , or - - - - - - - In our example, using lpr means the - printer needs a df capability in its entry in - /etc/printcap. - - FORTRAN - 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 mean print Printerleaf - files. - - - - Installing Conversion Filters - - Since conversion filters are programs you install outside of - the base &os; installation, they should probably go under - /usr/local. The directory - /usr/local/libexec is a popular location, - since they are specialized programs that only + 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 + tf + + + + + raster + vf + + + + + plain text + if + none, , or + + + + + + + In our example, using + lpr means the printer + needs a df capability in its entry in + /etc/printcap. + + FORTRAN + 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 mean print + Printerleaf files. + + + + Installing Conversion Filters + + Since conversion filters are programs you install outside of + the base &os; 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: - - # + 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:ms#-parenb cs8 clocal crtscts: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: + The DVI filter is a shell script named + /usr/local/libexec/psdf. Here is that + script: - #!/bin/sh + #!/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 + 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. The lprps utility will use those - arguments to account for the pages printed. - - - - More Conversion Filter Examples - - There is no fixed set of steps to install conversion - filters, some working examples are described in this section. 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 + passed to this script. The lprps utility will + use those arguments to account for the pages printed. + + + + More Conversion Filter Examples + + There is no fixed set of steps to install conversion + filters, some working examples are described in this section. + 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:$PATH; export PATH giftopnm | ppmtopgm | pgmtopbm | pbmtolj -resolution 300 \ && exit 0 \ || exit 2 - It works by converting the GIF file into a portable anymap, - converting that into a portable graymap, converting that into a - portable bitmap, and converting that into LaserJet/PCL-compatible - data. - - Here is the /etc/printcap file with an - entry for a printer using the above filter: + It works by converting the GIF file into a portable anymap, + converting that into a portable graymap, converting that into a + portable bitmap, and converting that into LaserJet/PCL-compatible + data. - # + Here is the /etc/printcap file with an + entry for a printer using the above filter: + + # # /etc/printcap for host orchid # teak|hp|laserjet|Hewlett Packard LaserJet 3Si:\ :lp=/dev/lpt0:sh:sd=/var/spool/lpd/teak:mx#0:\ :if=/usr/local/libexec/hpif:\ :vf=/usr/local/libexec/hpvf: - - The following script is a conversion filter for troff data - from the groff typesetting system for the &postscript; printer named - bamboo: - #!/bin/sh + The following script is a conversion filter for troff data + from the groff typesetting system for the &postscript; printer + named bamboo: + + #!/bin/sh # # pstf - Convert groff's troff data into PS, then print. # Installed in /usr/local/libexec/pstf # exec grops | /usr/local/libexec/lprps "$@" - - 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 + 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 + + 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 &os; Ports - Collection (see The Ports Collection) - has one: print/dvi2xx. - Installing this port gives us the program we need, - dvilj2p, which converts DVI into LaserJet IIp, - LaserJet III, and LaserJet 2000 compatible codes. - - The dvilj2p utility 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 + + 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 &os; Ports + Collection (see The Ports Collection) + has one: print/dvi2xx. + Installing this port gives us the program we need, + dvilj2p, which converts DVI into LaserJet IIp, + LaserJet III, and LaserJet 2000 compatible codes. + + The dvilj2p utility 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$$.dvi } # # Define a function to handle fatal errors: print the given message # and exit 2. Exiting with 2 tells LPD to do not try to reprint the # job. # fatal() { echo "$@" 1>&2 cleanup exit 2 } # # If user removes the job, LPD will send SIGINT, so trap SIGINT # (and a few other signals) to clean up after ourselves. # -trap cleanup 1 2 15 +trap cleanup 1 2 15 # # Make sure we are not colliding with any existing files. # cleanup # # Link the DVI input file to standard input (the file to print). # ln -s /dev/fd/0 hpdf$$.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. - - apsfilter - - printing - filters - apsfilter - - The &os; Ports Collection has a text filter that performs - automatic conversion called apsfilter (print/apsfilter). It can - detect plain text, &postscript;, DVI and almost any kind of files, run the proper - conversions, and print. - + + + + 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. + + apsfilter + + printing + filters + apsfilter + + The &os; Ports Collection has a text filter that performs + automatic conversion called apsfilter + (print/apsfilter). It can + detect plain text, &postscript;, DVI and almost any kind of + 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 + 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 + 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. + 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 &os; binary distribution is a text filter (input filter) - that can indent output (job submitted with lpr - ), allow literal characters to pass (job submitted - with lpr ), adjust the printing position for - backspaces and tabs in the job, and account for pages printed. It - can also act like an output filter. - - The lpf filter 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. - - page accounting - - accounting - printer - - 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. + <command>lpf</command>: a Text Filter + + The program /usr/libexec/lpr/lpf that comes + with &os; binary distribution is a text filter (input filter) + that can indent output (job submitted with + lpr ), allow literal + characters to pass (job submitted with + lpr ), adjust the printing + position for backspaces and tabs in the job, and account for pages + printed. It can also act like an output filter. + + The lpf filter 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. + + page accounting + + accounting + printer + + 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. - + various printers, then you probably want to consider header + pages as a necessary evil. + - banner pages + banner pages header pages header pages 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.) - + 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 section, 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 + 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 section, 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 the Output Filters section 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 the Output Filters section 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 ; see the Header Page Options section 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 ; see the + Header Page Options + section 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): - - k ll ll + 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: - - 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. + 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. - + - 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 - increase the page count by one by modifying the text filter or any of the - conversion filters (which do have user and host information) since - users can suppress header pages with lpr . - They could still be charged for header pages they did not print. - Basically, lpr 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 , 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 + 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 + increase the page count by one by modifying the text + filter or any of the conversion filters (which do have user and host + information) since users can suppress header pages with + lpr . They could still be + charged for header pages they did not print. Basically, + lpr 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 , 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. Section - Alternatives to the - Standard Spooler tells more about other spooling - software you can substitute for LPD. + + + + Install an alternative to LPD, + such as LPRng. 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. - - + + + + 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 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 - . - - 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 + 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 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 + . + + 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) ($date) ] { 270 y moveto show /y y 18 sub def } forall % % That is it % restore showpage EOF - Now, each of the conversion filters and the text filter can call - this script to first generate the header page, and then print the - user's job. Here is the DVI conversion filter from earlier in this - document, modified to make a header page: + Now, each of the conversion filters and the text filter can call + this script to first generate the header page, and then print the + user's job. Here is the DVI conversion filter from earlier in this + document, modified to make a header page: - #!/bin/sh + #!/bin/sh # # psdf - DVI to PostScript printer filter # Installed in /usr/local/libexec/psdf # # Invoked by lpd when user runs lpr -d # - + orig_args="$@" 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 , 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 , + 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 - + - printers - network + printers + network network printing &os; supports networked printing: sending jobs to remote - printers. Networked printing generally refers to two different - things: - + 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 to (or in place of) a - more conventional serial or parallel interface. Such a printer - might work as follows: - - - - It might understand the LPD + + 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 to (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. - - - + 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 the Simple - Printer Setup section. 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 Hosts). - - - printers - network - - network printing - If you are using a printer with a network interface that is - compatible with LPD, then the + 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 the Simple Printer Setup section. + 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 Hosts). + + + printers + network + + network printing + 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: - - # + 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 /var/spool/lpd/rattan /var/spool/lpd/bamboo + Then, we just need to make spooling directories on + orchid: + + &prompt.root; mkdir /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 bamboo 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 + + Now, users on orchid can print to + rattan and bamboo. If, for + example, a user on orchid typed: + + &prompt.user; lpr bamboo 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. + 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 (&os; 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 + 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 (&os; 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: $!"; while (<STDIN>) { print PRINTER; } exit 0; - - We can then use this script in various filters. Suppose we had - a Diablo 750-N line printer connected to the network. The printer - accepts data to print on port number 5100. The host name of the - printer is scrivener. Here is the text filter for the - printer: - - #!/bin/sh + + We can then use this script in various filters. Suppose we had + a Diablo 750-N line printer connected to the network. The printer + accepts data to print on port number 5100. The host name of the + printer is scrivener. Here is the text filter for + the printer: + + #!/bin/sh # # diablo-if-net - Text filter for Diablo printer `scrivener' listening # on port 5100. Installed in /usr/local/libexec/diablo-if-net # exec /usr/libexec/lpr/lpf "$@" | /usr/local/libexec/netprint scrivener 5100 - + Restricting Printer Usage - + - printers - restricting access to + printers + restricting access to - 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. - + 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 + Restricting Multiple Copies - The LPD system makes it easy for + The LPD system makes it easy for users to print multiple copies - of a file. Users can print jobs with lpr - (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 is a bit more delicate, so we will - disable multiple copies by adding the sc - capability: - - # + of a file. Users can print jobs with + lpr (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 is 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:ms#-parenb cs8 clocal crtscts: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): - - # + + 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. + + 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. - - If users outside the group (including root) - try to print to the controlled printer then they will be greeted with the - following message: - - lpr: Not a member of the restricted group - - 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: - - # + 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. + + If users outside the group (including root) + try to print to the controlled printer then they will be greeted + with the following message: + + lpr: Not a member of the restricted group + + 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:ms#-parenb cs8 clocal crtscts: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. - + 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 - - print jobs - 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. - - - print jobs - controlling - - 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: - - # + Controlling Sizes of Jobs Submitted + + print jobs + 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. + + + print jobs + controlling + + 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:ms#-parenb cs8 clocal crtscts: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 Hosts. + 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 Hosts. - + - Restricting Jobs from Remote Hosts - - 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 + Restricting Jobs from Remote Hosts + + 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. + /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 + 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 + + 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, the job will be refused. - - - - - 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:\ + 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, the job will be + refused. + + + + + 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:ms#-parenb cs8 clocal crtscts:rw:mx#5000:\ :if=/usr/local/libexec/psif:\ :df=/usr/local/libexec/psdf: - The spooling directory is 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 - - - - - - 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 computer resources, you can give them - token accounts, with no home directory and a - useless shell like /usr/bin/false. - - - + The spooling directory is 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 + + + + + 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 computer resources, you can give them + token accounts, with no home directory and a + useless shell like /usr/bin/false. + + + - + Accounting for Printer Usage - + - accounting - printer + accounting + printer 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? - + 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. - + 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. - + 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. - + + 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. - + + 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 - - &os; 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 + Quick and Dirty Printer Accounting + + &os; 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). The lpf filter 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: + arguments (from the pw and pl + capabilities). The lpf filter 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 + 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. An 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 + + 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. An 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 , to produce the following - summary: - - Login pages/feet runs price + + 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 , 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 - - makes each page cost one dollar and fifty cents. You can really - rake in the profits by using this option. - - Finally, running pac 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. + + + 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 + + makes each page cost one dollar and fifty cents. You can really + rake in the profits by using this option. + + Finally, running pac 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 is 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. + 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 is 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 - + printers usage - + This section tells you how to use printers you have set up with &os;. Here is an overview of the user-level commands: &man.lpr.1; Print jobs - + &man.lpq.1; Check printer queues - + &man.lprm.1; Remove jobs from a printer's queue - + There is also an administrative command, &man.lpc.8;, described in the section Administering Printers, used to control printers and their queues. 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 + 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 ... - + printing 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: + you list no files, &man.lpr.1; reads data to print from standard + input. For example, this command prints some important system + files: &prompt.user; lpr /etc/host.conf /etc/hosts.equiv - + To select a specific printer, type: - + &prompt.user; lpr printer-name filename ... This example prints a long listing of the current directory to the printer named rattan: - + &prompt.user; ls | lpr 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 - command. - + + 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 + 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 - + print 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. + 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. To display the queue for the default printer, type &man.lpq.1;. For a specific printer, use the option. For example, the command &prompt.user; lpq bamboo 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 + &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 file she is trying to print is too long to - fit, so the &man.lpq.1; command just shows three dots. + job came from user mary; it is a much larger + job. The pathname of the file she is trying to print is too long to + fit, so the &man.lpq.1; command just shows three dots. 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 + it tells what the printer is currently doing (or at least what LPD thinks the printer is doing). The &man.lpq.1; command also support a option to generate a detailed long listing. Here is an example of lpq : - + waiting for bamboo to become ready (offline ?) kelly: 1st [job 009rose] /etc/host.conf 73 bytes /etc/hosts.equiv 15 bytes kelly: 2nd [job 010rose] (standard input) 1635 bytes mary: 3rd [job 011rose] /home/orchid/mary/research/venus/alpha-regio/mapping 78519 bytes 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 bamboo 10 - + The &man.lprm.1; command has a few shortcuts: - + lprm - 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. + 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, + 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 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: - + 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 rattan myfile &prompt.user; rlogin orchid &prompt.user; lpq rattan Rank Owner Job Files Total Size active seeyan 12 ... 49123 bytes 2nd kelly 13 myfile 12 bytes &prompt.user; lprm rattan 13 rose: Permission denied &prompt.user; logout &prompt.user; lprm rattan 13 dfA013rose dequeued cfA013rose dequeued - + Beyond Plain Text: Printing Options - + 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 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. - - &tex; + + &tex; For example, the following command prints a DVI file (from the - &tex; typesetting system) named fish-report.dvi + &tex; typesetting system) named + fish-report.dvi to the printer named bamboo: - + &prompt.user; lpr 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 + (say) DVI and ditroff files together in a job. Instead, submit the files as separate jobs, using a different conversion option for each job. 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. 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 -man | lpr - + 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 + 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 + 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: - + parser.c + followed by three copies of + parser.h + to the default printer: + &prompt.user; lpr 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. + 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 + 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. + 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 + 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. - + Administering 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;, + 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. + 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 take 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 is 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. + 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 is running, 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. + 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. + &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 + 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 + 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. - + 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 &os;. You can probably appreciate - many of its shortcomings, which naturally leads to the question: - What other spooling systems are out there (and work with - &os;)? + have learned just about everything there is to know about the + LPD spooling system that comes with &os;. + You can probably appreciate many of its shortcomings, which naturally + leads to the question: What other spooling systems are out there + (and work with &os;)? LPRng - LPRng + 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 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 . + CUPS - CUPS + CUPS CUPS, the Common UNIX Printing System, provides a portable printing layer for &unix;-based operating systems. It has been developed by Easy Software Products to promote a standard printing solution for all &unix; vendors and users. CUPS uses the Internet Printing Protocol (IPP) as the basis for managing print jobs and queues. The Line Printer Daemon (LPD), Server Message Block (SMB), and AppSocket (a.k.a. JetDirect) protocols are also supported with reduced functionality. CUPS adds network printer browsing and PostScript Printer Description (PPD) based printing options to support real-world printing under &unix;. The main site for CUPS is . 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: #!/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 MS-DOS - OS/2 - ASCII + OS/2 + ASCII 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;, &os2;, and others uses a pair of + operating systems use a single character: ASCII code 10, the + line feed (LF). &ms-dos;, &os2;, 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 &os;, 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 + 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 &os; 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 + If you boot your system into other operating systems besides &os;, 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 &os;'s serial line driver automatically convert LF to CR+LF. Of course, this works with printers on serial ports only. To enable this feature, use the ms# capability and set the onlcr mode in the /etc/printcap file for the printer. Send an escape code to the - printer to have it temporarily treat LF characters + 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. PCL 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 + 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: - + 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 &os; 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: If the printer supports XON/XOFF flow control, have &os; use it by specifying the ixon mode in the ms# capability. - If the printer supports the Request to Send / Clear to Send hardware handshake (commonly known as RTS/CTS), specify - the crtscts mode in the - ms# capability. - Make sure the cable connecting the printer to the computer - is correctly wired for hardware flow control. + If the printer supports the Request to Send / Clear to + Send hardware handshake (commonly known as + RTS/CTS), specify the + crtscts mode in the ms# + capability. Make sure the cable connecting the printer to the + computer is correctly wired for hardware flow control. 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 setting in the - ms# capability; make sure the printer is - using the same settings as specified in the + parity setting in the ms# capability; 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 &os; 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. + LPD uses + /dev/console as a + default. -