Index: usr.bin/posixshmcontrol/Makefile =================================================================== --- usr.bin/posixshmcontrol/Makefile +++ usr.bin/posixshmcontrol/Makefile @@ -3,6 +3,5 @@ PROG= posixshmcontrol LIBADD= util WARNS?= 6 -MAN= .include Index: usr.bin/posixshmcontrol/posixshmcontrol.1 =================================================================== --- /dev/null +++ usr.bin/posixshmcontrol/posixshmcontrol.1 @@ -0,0 +1,153 @@ +.\" Copyright (c) 2019 The FreeBSD Foundation, Inc. +.\" All rights reserved. +.\" +.\" This documentation was written by +.\" Konstantin Belousov under sponsorship +.\" from the FreeBSD Foundation. +.\" +.\" Redistribution and use in source and binary forms, with or without +.\" modification, are permitted provided that the following conditions +.\" are met: +.\" 1. Redistributions of source code must retain the above copyright +.\" notice, this list of conditions and the following disclaimer. +.\" 2. Redistributions in binary form must reproduce the above copyright +.\" notice, this list of conditions and the following disclaimer in the +.\" documentation and/or other materials provided with the distribution. +.\" +.\" THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND +.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE +.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE +.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL +.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS +.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) +.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT +.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY +.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF +.\" SUCH DAMAGE. +.\" +.\" $FreeBSD$ +.\" +.Dd May 27, 2019 +.Dt POSIXSHMCONTROL 1 +.Os +.Sh NAME +.Nm posixshmcontrol +.Nd Control POSIX shared memory segments +.Sh SYNOPSIS +.Nm +.Ar create +.Op Fl m Ar mode +.Op Pa path \&... +.Nm +.Ar rm +.Op Pa path \&... +.Nm +.Ar ls +.Op Fl h +.Op Fl n +.Nm +.Ar dump +.Op Pa path \&... +.Nm +.Ar stat +.Op Fl h +.Op Fl n +.Op Pa path \&... +.Nm +.Ar truncate +.Op Fl s Ar length +.Op Pa path \&... +.Sh DESCRIPTION +The +.Nm +command manipulates the named POSIX shared memory segments. +It allows inspecting existing segments, dumping their metadata or contents, +and unlinking them. +.Pp +Unlinking removes the name from the system and, when the last process +unmaps the segment and closes file descriptor pointing to the segment, +frees underlying memory. +.Pp +The number of hard links as displayed by the +.Ic stat +subcommand, is equal to the number of references to the underlying VM +object. +It is almost always equal to the number of mappings +1, except +for transient references. +.Pp +The following subcommands are provided: +.Bl -tag -width truncate +.It Ic create +Create segments with the specified paths, if not exist. +The +.Ar mode +optional numerical argument specifies initial access mode. +.It Ic rm +Unlink the paths specified. +.It Ic ls +List all linked named shared memory segments visible to the caller. +For each segment, the user and group owner, size, and path are displayed. +.It Ic dump +Output raw bytes values from the segment to standard output. +.It Ic stat +Print metadata for the specified path, in the format similar to the +.Xr stat 1 +utility. +.It Ic truncate +Change the length of the segments. +Argument to the +.Fl s +option specifies new length, the human-friendly 'k', 'm', 'g' suffixes +can be used, see +.Xr expand_number 3. +If the option is not specified, assumed length is zero. +.El +.Pp +For some commands, the following options may be provided: +.Bl -tag XX +.It Fl h +If specified, requests human-readable display of size, see +.Xr humanize_number 3 . +.It Fl n +Prevent translation of owner and group into symbolic names +using name-switch services, instead the raw numeric values are printed. +.El +.Sh EXIT STATUS +.Ex -std +.Sh EXAMPLES +.Bl -bullet +.It +To show content of the shared memory segment with the path +.Pa /1 , +use the command +.Dl "posixshmcontrol dump /q | hexdump -C" +.It +To create a segment with the path +.Pa /2 +and then enlarge it to 1M, use the sequence of commands +.Dl "posixshmcontrol create /2" +.Dl "posixshmcontrol truncate -s 1m /2" +.El +.Sh SEE ALSO +.Xr hexdump 1 , +.Xr stat 1 , +.Xr ftruncate 2 , +.Xr read 2 , +.Xr shm_open 2 , +.Xr shm_unlink 2 , +.Xr stat 2 , +.Xr expand_number 3 , +.Xr humanize_number 3 , +.Xr sysctl 3 +.Sh HISTORY +The +.Nm +command appeared in +.Fx 13.0 . +.Sh AUTHORS +The +.Nm +command and this manual page were written by +.An Konstantin Belousov Aq Mt kib@freebsd.org +under sponsorship from The FreeBSD Foundation.