diff options
Diffstat (limited to 'doc')
| -rw-r--r-- | doc/info/bus.texinfo | 2079 | ||||
| -rw-r--r-- | doc/info/fdl.texinfo | 505 | ||||
| -rw-r--r-- | doc/man/bus-broadcast.1 | 35 | ||||
| -rw-r--r-- | doc/man/bus-chgrp.1 | 38 | ||||
| -rw-r--r-- | doc/man/bus-chmod.1 | 49 | ||||
| -rw-r--r-- | doc/man/bus-chown.1 | 41 | ||||
| -rw-r--r-- | doc/man/bus-create.1 | 37 | ||||
| -rw-r--r-- | doc/man/bus-listen.1 | 32 | ||||
| -rw-r--r-- | doc/man/bus-remove.1 | 29 | ||||
| -rw-r--r-- | doc/man/bus-wait.1 | 33 | ||||
| -rw-r--r-- | doc/man/bus.1 | 77 | ||||
| -rw-r--r-- | doc/man/bus.5 | 50 | ||||
| -rw-r--r-- | doc/man/bus_chmod.3 | 64 | ||||
| -rw-r--r-- | doc/man/bus_chown.3 | 51 | ||||
| -rw-r--r-- | doc/man/bus_close.3 | 36 | ||||
| -rw-r--r-- | doc/man/bus_create.3 | 63 | ||||
| -rw-r--r-- | doc/man/bus_open.3 | 67 | ||||
| -rw-r--r-- | doc/man/bus_poll.3 | 87 | ||||
| -rw-r--r-- | doc/man/bus_read.3 | 79 | ||||
| -rw-r--r-- | doc/man/bus_unlink.3 | 56 | ||||
| -rw-r--r-- | doc/man/bus_write.3 | 64 | ||||
| -rw-r--r-- | doc/man/libbus.7 | 39 | ||||
| -rw-r--r-- | doc/protocol | 1 |
23 files changed, 0 insertions, 3612 deletions
diff --git a/doc/info/bus.texinfo b/doc/info/bus.texinfo deleted file mode 100644 index be50cea..0000000 --- a/doc/info/bus.texinfo +++ /dev/null @@ -1,2079 +0,0 @@ -\input texinfo @c -*-texinfo-*- - -@c %**start of header -@setfilename bus.info -@settitle bus -@afourpaper -@documentencoding UTF-8 -@documentlanguage en -@finalout -@c %**end of header - - -@dircategory Interprorcess Communication -@direntry -* bus: (bus). A simple daemonless system for broadcasting messages locally -@end direntry - - -@copying -Copyright @copyright{} 2015 Mattias Andrée - -@quotation -Permission is granted to copy, distribute and/or modify this document -under the terms of the GNU Free Documentation License, Version 1.3 or -any later version published by the Free Software Foundation; with no -Invariant Sections, with no Front-Cover Texts, and with no Back-Cover -Texts. A copy of the license is included in the section entitled -``GNU Free Documentation License''. -@end quotation -@end copying - -@ifnottex -@node Top -@top bus -- A simple daemonless system for broadcasting messages locally -@insertcopying -@end ifnottex - -@titlepage -@title bus -@subtitle A simple daemonless system for broadcasting messages locally -@author by Mattias Andrée (maandree) - -@page -@vskip 0pt plus 1filll -@insertcopying -@page -@end titlepage - -@contents - - -@iftex -@macro xrm{} -@rm{} -@end macro -@macro xtt{} -@tt{} -@end macro -@end iftex - -@ifnottex -@macro xrm{} -@end macro -@macro xtt{} -@end macro -@end ifnottex - -@menu -* Overview:: Brief overview of @command{bus}. -* Standard:: How to use @command{bus} properly. -* Invoking:: Executing @command{bus}. -* Interface:: Using @command{libbus}. -* Protocol:: How communication over @command{bus} works internally. -* Rationale:: Why @command{bus}? -* Examples:: Usecase examples and API-demonstration. -* GNU Free Documentation License:: Copying and sharing this manual. - -@detailmenu - --- The Detailed Node Listing --- - -Invoking - -* bus create:: Create a bus. -* bus remove:: Remove a bus. -* bus listen:: Listen for new message on a bus. -* bus wait:: Listen for one new message only on a bus. -* bus broadcast:: Broadcast a message on a bus. -* bus chmod:: Change permissions on a bus. -* bus chown:: Change ownership of a bus. -* bus chgrp:: Change group ownership of a bus. - -Examples - -* Audio-volume control:: -* Telephony and music:: -* Timed:: -* Nonblocking:: -* Daemon-dependencies:: - -@end detailmenu -@end menu - - - -@node Overview -@chapter Overview - -@command{bus} is a stupid-simple, thrilless, daemonless interprocess -communication system for broadcasting messages. It is a lightweight -alternative to a two-phase interprocess flexible barrier. - -@command{bus} uses a System V semaphore array and System V shared -memory. Buses are named; the key of the semaphore array and the -shared memory is stored in a regular file. - -The shared memory used by @command{bus} is always 2048 bytes. -Additionally all messages should be encoded in UTF-8 and not contain -any NULL characters, except they @emph{must} always end with a NULL -byte. Furthermore messages should be prefixed with the process -identifer of the process whence the message originated, followed -by a space. If the process is ephemeral@footnote{The process exits -after the broadcast, or shortly thereafter.}, 0 should be used -instead of the process identifier. - -Communication over @command{bus} is synchronous. The broadcast call -does not return until all listeners have received (and copied) the -message. A malfunctioning program can lock the bus. - -This software package contains a C library and a command line -utility. The package python-bus provides a Python 3 module. - - - -@node Standard -@chapter Standard - -The command @command{bus create} can be used to create new buses. By -convention, buses should be stored in @file{$XDG_RUNTIME_DIR/bus}, -this is what @command{bus create} does if no pathname is given. The -pathname of the bus should be tracked using @env{BUS_X}, where @env{X} -is replaced with either: - -@table @env -@item GENERIC -For the bus used in generic cases. That is all but the cases -of the buses listed below. -@item AUDIO -For the bus used in with the audio subsystem is involved. -@item VIDEO -For the bus used in with the video subsystem is involved. -@item INPUT -For the bus used in with the input subsystem is involved. -@item FILES -For the bus used in with the storage subsystem is involved. -@end table - -This list may be extended in the future. Therefore, and for -other conventions, project-private buses should be tracked -using @env{X_BUS}, where @env{X} is the project name. - -Messages broadcasted on a bus cannot be longer than 2047 bytes, -excluding NUL termination. Message should be encoded in UTF-8, -and most not contain the NUL character. - -Broadcasted message should start with the process ID whence -the message originated, followed by a single regular space. -If the process is ephemeral@footnote{The process exits after -the broadcast, or shortly thereafter.}, 0 should be used instead -of the process identifier. - - - -@node Invoking -@chapter Invoking - -@command{bus} includes the following commands: - -@table @command -@item create -Create a bus. -See @ref{bus create} for more information. -@item remove -Remove a bus. -See @ref{bus remove} for more information. -@item listen -Listen for new message on a bus. -See @ref{bus listen} for more information. -@item wait -Listen for one new message only on a bus. -See @ref{bus wait} for more information. -@item broadcast -Broadcast a message on a bus. -See @ref{bus broadcast} for more information. -@item chmod -Change permissions on a bus. -See @ref{bus chmod} for more information. -@item chown -Change ownership of a bus. -See @ref{bus chown} for more information. -@item chgrp -Change group ownership of a bus. -See @ref{bus chgrp} for more information. -@end table - -Upon successful completion, these commands exit with the value -0. On failure, they exit with the value 1. If the command is -not recognised the exit value is 2. - -@menu -* bus create:: Create a bus. -* bus remove:: Remove a bus. -* bus listen:: Listen for new message on a bus. -* bus wait:: Listen for one new message only on a bus. -* bus broadcast:: Broadcast a message on a bus. -* bus chmod:: Change permissions on a bus. -* bus chown:: Change ownership of a bus. -* bus chgrp:: Change group ownership of a bus. -@end menu - - - -@node bus create -@section @command{bus create} - -The syntax for invocation of @command{bus create} is -@example -bus create [-x] [--] [@var{PATHNAME}] -@end example - -The command creates a bus and stores the key to it in the -file @var{PATHNAME}. If @var{PATHNAME} is omitted, a -random pathname in @file{$XDG_RUNTIME_DIR/bus} will be -used and printed to stdout. - -If @option{-x} is used, the command will fail if -the file @var{PATHNAME} already exists. - - - - -@node bus remove -@section @command{bus remove} - -The syntax for invocation of @command{bus remove} is -@example -bus remove [--] @var{PATHNAME} -@end example - -The command removes the bus whose key is stored in -the file @var{PATHNAME}. The file holding the -key is also unlinked. - - - -@node bus listen -@section @command{bus listen} - -The syntax for invocation of @command{bus command} is -@example -bus listen [--] @var{PATHNAME} @var{COMMAND} -@end example - -The command listens for new messages on the bus whose -key is stored in the file @var{PATHNAME}. Once a message -is received, @var{COMMAND} will be spawned with the -environment variable @env{msg} (lowercased) set to the -received message. @sc{POSIX} shell syntax applies to -@var{COMMAND}. - - -@node bus wait -@section @command{bus wait} - -The syntax for invocation of @command{bus wait} is -@example -bus wait [--] @var{PATHNAME} @var{COMMAND} -@end example - -The command listens for a new message on the bus whose -key is stored in the file @var{PATHNAME}. Once a message -is received, the process will stop listening for more -messages and @var{COMMAND} will be spawned with the -environment variable @env{msg} (lowercased) set to the -received message. @sc{POSIX} shell syntax applies to -@var{COMMAND}. - - - -@node bus broadcast -@section @command{bus broadcast} - -The syntax for invocation of @command{bus broadcast} is -@example -bus broadcast [-n] [--] @var{PATHNAME} @var{MESSAGE} -@end example - -The command broadcasts the message @var{MESSAGE} on the -bus whose key is stored in the file @var{PATHNAME}. - - - -@node bus chmod -@section @command{bus chmod} - -The syntax for invocation of @command{bus chmod} is -@example -bus chmod [--] @var{PERMISSIONS} @var{PATHNAME} -@end example - -This command changes who have access to the bus whose key -is stored in the file @var{PATHNAME}. In the permissions, -the owner, the group, and others (not in tgroup) are -represented by the symbols @code{u}@footnote{@code{u} -stands for `user'.}, @code{g}, and @code{o}, respectively. -The permissions string is imagined to have always be -prefixed with an @code{=}. This symbols means that all user -classes list after it, and only those classes, as permission -to use the bus. Similarly the symbols @code{+} and @code{-} -can be used to grant and revoke access, respectively. The -symbols @code{=}, @code{+}, and @code{-} can be mixed, and -are interpreted from left to right. Alternatively the -permissions string can be a octal number, where the owner -is represented by any bit in 700 (100, 200, or 400, or any -combination thereof), the group is represented by any bit -in 70, and others (not in the group) is represented by any -bit in 7. - -The current permission of the bus can be retrieved by -running @command{stat} over the file @var{PATHNAME}. - - - -@node bus chown -@section @command{bus chown} - -The syntax for invocation of @command{bus chown} is -@example -bus chown [--] @var{OWNER}[:@var{GROUP}] @var{PATHNAME} -@end example - -This command changes the owner, that owns the bus whose -key is stored in the file @var{PATHNAME}, to the specified -owner. The owner can be specified either with a numerical -user identifier or with a user name. If a group is -specified, the bus's owner-group will be set to that group, -otherwise the group will remain unchanged (not changed -to the group of the new owner.) The group can be specified -either with a numerical group identifier or with a group -name. - -The current ownership of the bus can be retrieved by -running @command{stat} over the file @var{PATHNAME}. - - - -@node bus chgrp -@section @command{bus chgrp} - -The syntax for invocation of @command{bus chgrp} is -@example -bus chgrp [--] @var{GROUP} @var{PATHNAME} -@end example - -This command changes the group, that owns the bus whose -key is stored in the file @var{PATHNAME}, to the specified -group. The group can be specified either with a numerical -group identifier or with a group name. - -The current ownership of the bus can be retrieved by -running @command{stat} over the file @var{PATHNAME}. - - - -@node Interface -@chapter Interface - -To use @command{libbus} in your C program, include the -header file @file{<bus.h>} and link with the flag -@option{-lbus}. - -With exception to @code{bus_poll} and @code{bus_poll_timed}, -all functions return @code{0} upon successful completion, -and @code{-1} in case of failure. @code{bus_poll} and -@code{bus_poll_timed} return @code{NULL} on failure. -On failure on all functions set @code{errno} to indicate -what went wrong. - -@file{<bus.h>} defines the following functions: - -@table @code -@item int bus_create(const char *file, int flags, char **out_file) -This function creates a bus with the asscoiated pathname -specifed by the value of the parameter @code{file}. If -@code{file} is @code{NULL} a random pathname is selected. -This pathname adheres to the convention set forth by -in @ref{Standard}. - -If @code{file} is not @code{NULL} the function fails if the -file already exists if @code{flags} contains @code{BUS_EXCL}. -Otherwise if @code{file} is not @code{NULL}, the function -does nothing if the file already exists. - -If @code{flags} contains @code{BUS_INTR}, the function fails -if it is interrupted. - -Unless @code{out_file} is NULL, the pathname of the bus -should be stored in a new char array stored in @code{*out_file}. -The caller must free the allocated stored in @code{*out_file}. - -If the processes cannot allocate enough memory to perform -the action, the function sets @code{errno} to @code{ENOMEM} -and fails. It may also fail and set @code{errno} to any of -the errors specified for the system calls @code{open} and -@code{write}. - -@item int bus_unlink(const char *file) -This function removes the bus assoicated with the pathname -stored in the parameter @code{file}. The function also -unlinks the file. - -The function may set @code{errno} to any of the following -values and fail for the specified reasons: -@table @code -@item EINVAL -The bus does not exist. -@item EACCES -Operation permission is denied to the calling process. -@item EPERM -The user does not have permission to remove the bus. -@end table -@noindent -It may also fail and set @code{errno} to any of the errors -specified for the system calls @code{unlink} and @code{open}, -and the functions @code{semget} and @code{shmget}. - -@item int bus_open(bus_t *bus, const char *file, int flags) -This function acquires resources required for the process -to use the bus associated with the filename stored in the -parameter @code{file}. The function also stores the resources -in @code{bus} for use by other @command{bus} functions. - -Values for @code{flags} are constructed by a bitwise -inclusive @sc{or} of flags from the following list. -@table @code -@item BUS_RDONLY -The process will only be using the bus for receiving messages. -@item BUS_WRONLY -The process will only be using the bus for sending messages. -@item BUS_RDWR -The process will use the bus for both receiving and sending -messages. -@end table - -The function may set @code{errno} to any of the following -values and fail for the specified reasons: -@table @code -@item ENOMEM -The process cannot allocate enough memory to perform the -action. -@item EACCES -Operation permission is denied to the calling process. -@item EINVAL -The described bus does not exist. -@end table -@noindent -It may also fail and set @code{errno} to any of the errors -specified for the system call @code{open}. - -@item int bus_close(bus_t *bus) -This function disposes of resources allocated to the -process, as referenced in the parameter @code{bus}. - -The function fails and sets @code{errno} to @code{EINVAL} -if the bus does not exist. - -@item int bus_write(const bus_t *bus, const char *message, int flags) -This function broadcasts a message on the bus whose -information is stored in the parameter @code{bus}. The -message read by the function is stored in the parameter -@code{message}. It may not exceeed 2048 bytes, including -NUL termination. - -The function shall fail, and set @code{errno} to -@code{EAGAIN}, if the call would suspend the process and -@code{flags} contains @code{BUS_NOWAIT}. - -The function may fail and set @code{errno} to any of the -errors specified for the function @code{semop}. - -@item int bus_write_timed(const bus_t *bus, const char *message, const struct timespec *timeout, clockid_t clockid) -This function behaves like @code{bus_write}, except if it -is not able to write the message within the specified time, -it will fail and set @code{errno} to @code{EAGAIN}. The -time is specified as an absolute time using the parameter -@code{timeout}. The behaviour is unspecified if @code{timeout} -is @code{NULL}. @code{timeout} is measured with the clock whose -identifier is specified by the parameter @code{clockid}. This -clock must be a predicitable clock@footnote{There are probably -other, undocumented, seemingly arbitrary restrictions too.}. - -The function may fail and set @code{errno} to any of the -errors specified for the functions @code{semop} and -@code{clock_gettime}. - -@item int bus_read(const bus_t *bus, int (*callback)(const char *message, void *user_data), void *user_data) -This function waits for new message to be sent on the bus -specified in the @code{bus} parameter, as provieded by a -previous call to the function @code{bus_open}. Once a -message is received, the parameter-function @code{callback} -is invoked. The parameter @code{message} in @code{callback} -is the received message, and @code{user_data} in -@code{callback} should be @code{user_data} from @code{bus_read}. -However, once the function [@code{bus_read}] has ensured -that it will receive any message sent on the bus, it shall -invoke the parameter-function @code{callback} with -@code{message} set to @code{NULL}, to notify the process that -it can perform any action that requires that it is listening -on the bus. - -After @code{callback} returns, @code{message} may be override. -Therefore @code{callback} should copy message and start a new -thread that uses the copy of @code{message}. @code{callback} -shall return @code{-1} on failure, @code{0} if the function -[@code{bus_read}] should stop listening, or @code{1} if -the function should continue listening. - -The function may fail and set @code{errno} to any of the -errors specified for the function @code{semop}. - -@item int bus_read_timed(const bus_t *bus, int (*callback)(const char *message, void *user_data), void *user_data, const struct timespec *timeout, clockid_t clockid) -This function behaves like @code{bus_read}, except it will -automatically fail and set @code{errno} to @code{EAGAIN} when -the specified time has passed. The time is specified as an -absolute time using the parameter @code{timeout}. The -behaviour is unspecified if @code{timeout} is @code{NULL}. -@code{timeout} is measured with the clock whose identifier -is specified by the parameter @code{clockid}. This clock -must be a predicitable clock@footnote{There are probably -other, undocumented, seemingly arbitrary restrictions too.}. - -The function may fail and set @code{errno} to any of the -errors specified for the functions @code{semop} and -@code{clock_gettime}. - -@item int bus_poll_start(bus_t *bus) -@itemx int bus_poll_stop(const bus_t *bus) -@itemx const char *bus_poll(bus_t *bus, int flags) -@itemx const char *bus_poll_timed(bus_t *bus, const struct timespec *timeout, clockid_t clockid) -The function @code{bus_poll} waits for a message to be -broadcasted on the bus, and return the message it receives. -The function fails if @code{flags} contains @code{BUS_NOWAIT} -and there is not already a message waiting on the bus. -Received messages shall be copied and parsed, and acted -upon, in a separate thread, and the function @code{bus_poll} -or the function @code{bus_poll_stop} called again as soon -as possible. - -The funcion @code{bus_poll_start} must be called before -@code{bus_poll} is called for the first time. When the -process is done listening on the bus, it must call the -function @code{bus_poll_stop}. - -The function @code{bus_poll_timed} behaves like the function -@code{bus_poll}, except if it is not able to read a message -within the specified time, it will fail and set @code{errno} -to @code{EAGAIN}. The time is specified as an absolute time -using the parameter @code{timeout}. The behaviour is -unspecified if @code{timeout} is @code{NULL}. @code{timeout} -is measured with the clock whose identifier is specified by -the parameter @code{clockid}. This clock must be a predicitable -clock@footnote{There are probably other, undocumented, -seemingly arbitrary restrictions too.}. - -Upon successful completion, the functions @code{bus_poll} and -@code{bus_poll_timed} returns the received message. - -These functions may fail and set @code{errno} to any of the -errors specified for the function @code{semop}. The function -@code{bus_poll_timed} may also set @code{errno} to any of -the errors specified for @code{clock_gettime}. - -@item int bus_chown(const char *file, uid_t owner, gid_t group) -This function changes the owner and the group of the bus, -associated with the file whose pathname is stored in the -parameter @code{file}, to the owner and group specified by -the parameters @code{owner} and @code{group}, respectively. - -The current ownership of a bus can be retrieved by calling -@code{stat} over the pathname of the bus. - -The function may fail and set @code{errno} to any of the -errors specified for the functions @code{bus_open}, -@code{chown}, @code{semget}, @code{shmget}, and @code{shmctl} -as well as any errors specified for the commands -@code{IPC_STAT} and @code{IPC_SET} for the function -@code{semctl}. - -@item int bus_chmod(const char *file, mode_t mode) -This function gives access to the bus associated with the -file whose pathname is stored in the parameter @code{file} -according to the following rules: - -@itemize @bullet{} -@item -If @code{mode} contains any of the bits @code{S_IRWXU} -contains, the owner should be given full access to the -bus. Otherwise the owner should have no access. -@item -If @code{mode} contains any of the bits @code{S_IRWXG} -contains, the group should be given read and write -access to the bus. Otherwise the group should have no -access. -@item -If @code{mode} contains any of the bits @code{S_IRWXO} -contains, users that are neither the owner nor member -of the group should be given read and write access to -the bus. Otherwise they should have no access. -@end itemize - -The current permissions of a bus can be retrieved by calling -@code{stat} over the pathname of the bus. - -The function may fail and set @code{errno} to any of the -errors specified for the functions @code{bus_open}, -@code{chmode}, @code{semget}, @code{shmget}, and @code{shmctl} -as well as any errors specified for the commands -@code{IPC_STAT} and @code{IPC_SET} for the function -@code{semctl}. -@end table - -There is not reason for poking around in @code{bus_t} -(@code{struct bus}). It should be considered opaque. -You can read the documentation in @file{<bus.h>} if -you want to know what is in it. - - - - -@node Protocol -@chapter Protocol - -@command{bus} is built upon following three procedures. - -@noindent -@code{create} -@example -@w{@xrm{}Select a filename.@xtt{}} - -@w{@xrm{}Create XSI semaphore array @{@code{S} = 0, @code{W} = 0, @code{X} = 1, @code{Q} = 0, @code{N} = 0@}@xtt{}} -@w{@xrm{}with random key. Store the semaphore array's key in decimal form@xtt{}} -@w{@xrm{}on the first line in the selected file.@xtt{}} - -@w{@xrm{}Create XSI shared memory, with an allocation of 2048 bytes, with@xtt{}} -@w{@xrm{}a random key. Store the shared memory's key in decimal form on@xtt{}} -@w{@xrm{}the second line in the selected file.@xtt{}} -@end example - -@noindent -@code{broadcast} -@example -with P(X): - Z(W) - @w{@xrm{}Write NUL-terminate message to shared memory@xtt{}} - with V(N): -- (1) - Q := 0 - Z(S) - --- (1) @w{@xrm{}may be omitted if semaphores are known that@xtt{}} - @w{P()@xrm{}, @xtt{}Z()@xrm{}, @xtt{}V()@xrm{} cannot create a race condition@xtt{}} - @w{@xrm{}with a processes running @xtt{}Z()@xrm{}.@xtt{}} -@end example - -@noindent -@code{listen} -@example -with V(S): - forever: - V(Q) - Z(Q) - @w{@xrm{}Read NUL-terminated message from shared memory@xtt{}} - if breaking: - break - with V(W): - with P(S): - Z(S) - Z(N) -@end example - -@noindent -@code{V(a)} means that semaphore a is released.@* -@code{P(a)} means that semaphore a is acquired.@* -@code{Z(a)} means that the process waits for semaphore a to become 0.@* -@code{with P(a)} that @code{P(a)} is done before the entering the scope, -and @code{V(a)} is done when exiting the scope. It also means that -these actions [@code{P(a)} and @code{V(a)}] are undone when the process -exits, or if the call fails.@* -@code{with V(a)} is to @code{V(a)} as @code{with P(a)} is to @code{P(a)}. - - - -@node Rationale -@chapter Rationale - -We need an interprocess communication system similar -to message queues. But we need broadcasting rather than -anycasting, so we have a fast, simple and daemonless -system for announcing events to any processes that -might be interested. - - - -@node Examples -@chapter Examples - -This chapter contains usecase examples and -API-demonstrations. You will find that they are (on -a standard installation) installed on your system. - -@menu -* Audio-volume control:: -* Telephony and music:: -* Timed:: -* Nonblocking:: -* Daemon-dependencies:: -@end menu - - - - -@node Audio-volume control -@section Audio-volume control - -Assume you have program that display the audio volume. -This program checks every second third if the volume -have changed. - -Also assume that you use @command{amixer} to change the -volume, most often by using keybindings via @command{xbindkeys}. - -To reduce the delay, you want to send a signal to the -monitor program that the volume have changed. For this -more primitive IPC is sufficient, but lets assume there -are other programs interested in this information too. - -To accomplish this, you create a wrapper for @command{amixer} -that broadcasts updates on a bus. This wrapper is -installed as @command{~/.local/bin/amixer}, and -@command{~/.local/bin/} is included in @env{$PATH} -before @command{/usr/bin}. -@* - -@noindent -Before starting run @command{./init}, this code is -should be run from your profile file if you want to -implement this on your system. After running -@command{./init}, you can start one or more listeners -by running @command{./alsa-monitor}. - -To change the volume run -@code{./amixer -c 0 -- set Master 5%+} or similar. - -When you are done run @command{./cleanup}. - - -@subsubheading @file{./amixer} -@example -#!/bin/sh -/usr/bin/amixer "$@@" -for arg in "$@@"; do - if [ "$@{arg@}" = "set" ] || \ - [ "$@{arg@}" = "sset" ] || \ - [ "$@{arg@}" = "cset" ]; then - exec bus broadcast "/tmp/example-bus" '0 volume-changed *' - fi -done -@end example - - -@subsubheading @file{./cleanup} -@example -#!/bin/sh -exec bus remove "/tmp/example-bus" -@end example - - -@subsubheading @file{./init} -@example -#!/bin/sh -bus create "/tmp/example-bus" - -# @w{@xrm{}The following code is more suitable in the real world,@xtt{}} -# @w{@xrm{}if used, the other files should use @xtt{}"$@{BUS_AUDIO@}"} -# @w{@xrm{}instead of @xtt{}"/tmp/example-bus"@xrm{}.@xtt{}} -# -# export BUS_AUDIO="$@{XDG_RUNTIME_DIR@}/bus/audio" -# if [ ! -f "$@{BUS_AUDIO@}" ]; then -# bus create "$@{BUS_AUDIO@}" -# fi -@end example - - -@subsubheading @file{./monitor} -@example -#!/bin/sh -if [ $# = 1 ]; then - if [ "$(echo "$@{1@}" | cut -d ' ' -f 2)" = "volume-changed" ]; then - printf '\e[H\e[2J' - amixer get Master - fi - exit 0 -fi - -exec 2>/dev/null - -printf '\e[?1049h\e[H\e[2J' -trap -- "printf '\e[?1049l'" SIGINT -bus listen "/tmp/example-bus" \'"$@{0/\'/\'\\\'\'@}"\'' "$@{msg@}"' -@end example - - - -@node Telephony and music -@section Telephony and music - -Assume you have a music player and a telephony program. -You might like it if the music player pauses whenever -you make or receive a call. You may also like it, if -the music resumed when the call ended. - -In this example we will assume you the have @command{mocp} -(@command{moc} package) running. And we will use the shell to -simulate a telephony program. -@* - -@noindent -First of, run make to build this example. Before -starting run @command{./init}. And when you are -done run @command{./cleanup}. - -In one terminal run @command{./monitor}. This program -will pause @command{mocp} when you make or receive a call, -it will also resume @command{mocp} when all calls have -ended if it did pause @command{mocp}. - -Then start any positive number of terminals. -We will pretend that each of them are telephony -programs. To make or receive a call, run -@command{./receive-or-make-call}, when you want to -end the pretend call, run @command{./end-call} from -the terminal (or more accurately, from the same -process.) - - -@subsubheading @file{./Makefile} -@example -COMMANDS = init cleanup monitor end-call receive-or-make-call - -all: $@{COMMANDS@} -%: %.c - $@{CC@} -Wall -Wextra -pedantic -std=c99 -lbus -o $@@ $< -clean: - -rm $@{COMMANDS@} - -.PHONY: all clean -@end example - - -@subsubheading @file{./cleanup.c} -@example -#include <bus.h> -#include <stdio.h> - -int main() -@{ - return bus_unlink("/tmp/example-bus") && (perror("cleanup"), 1); -@} -@end example - - -@subsubheading @file{./end-call.c} -@example -#include <bus.h> -#include <stdio.h> -#include <unistd.h> -#include <stdint.h> - -#define t(stmt) if (stmt) goto fail - -static char message[BUS_MEMORY_SIZE]; - -int main() -@{ - bus_t bus; - sprintf(message, "%ji unforce-pause", (intmax_t)getppid()); - /* @w{@xrm{}Yes, PPID; in this example we pretend the shell is the telephony process.@xtt{}} */ - t (bus_open(&bus, "/tmp/example-bus", BUS_WRONLY)); - t (bus_write(&bus, message, 0)); - bus_close(&bus); - return 0; - -fail: - perror("end-call"); - bus_close(&bus); - return 1; -@} -@end example - - -@subsubheading @file{./init.c} -@example -#include <bus.h> -#include <stdio.h> - -int main() -@{ - return bus_create("/tmp/example-bus", 0, NULL) && (perror("init"), 1); -@} -@end example - - -@subsubheading @file{./monitor.c} -@example -#include <bus.h> -#include <stdio.h> -#include <stdlib.h> -#include <string.h> - -static size_t pauser_count = 0; -static size_t pausers_size = 0; -static char* pausers = NULL; - -static int is_moc_playing(void) -@{ - return !WEXITSTATUS(system("env LANG=C mocp -i 2>/dev/null |" - "grep 'State: PLAY' >/dev/null")); -@} - -/* @w{@xrm{}In a proper implementation, message whould be copyied, and then@xtt{}} - * @w{@xrm{}a new thread would be created that parsed the copy. But that is@xtt{}} - * @w{@xrm{}too much for an example, especially since it would also require@xtt{}} - * @w{@xrm{}a mutex to make sure two threads do not modify data at the same@xtt{}} - * @w{@xrm{}time, causing chaos.@xtt{}} */ -static int callback(const char *message, void *user_data) -@{ - char *msg = NULL; - size_t len = 0; - if (message == 0) - return 1; - while ((len < 2047) && message[len]) - len++; - msg = malloc((len + 1) * sizeof(char)); - t (msg == NULL); - memcpy(msg, message, len * sizeof(char)); - msg[len] = 0; - /* @w{@xrm{}BEGIN run as in a separate thread@xtt{}} */ - if (pauser_count || is_moc_playing()) @{ - char *begin = strchr(msg, ' '); - ssize_t pid; - int requests_pause; - if (begin == NULL) - goto done; - *begin++ = 0; - pid = (ssize_t)atoll(msg); - if (pid < 1) /* @w{@xrm{}We need a real PID, too bad there is@xtt{}} - * @w{@xrm{}no convient way to detect if it dies.@xtt{}} */ - goto done; - if ((strstr(begin, "force-pause ") == begin) || - !strcmp(begin, "force-pause")) - requests_pause = 1; - else if ((strstr(begin, "unforce-pause ") == begin) || - !strcmp(begin, "unforce-pause")) - requests_pause = 0; - else - goto done; - if ((size_t)pid >= pausers_size) @{ - pausers = realloc(pausers, (size_t)(pid + 1) * sizeof(char)); - t (pausers == NULL); /* @w{@xrm{}Let's ignore the memory leak.@xtt{}} */ - memset(pausers + pausers_size, 0, - ((size_t)(pid + 1) - pausers_size) * sizeof(char)); - pausers_size = (size_t)(pid + 1); - @} - if (pausers[pid] ^ requests_pause) @{ - pauser_count += requests_pause ? 1 : -1; - pausers[pid] = requests_pause; - if (pauser_count == (size_t)requests_pause) - system(requests_pause ? "mocp -P" : "mocp -U"); - @} - @} - /* @w{@xrm{}END run as in a separate thread@xtt{}} */ - goto done; - (void) user_data; - -fail: - perror("monitor"); - return -1; - -done: - free(msg); - return 1; -@} - -int main() -@{ - bus_t bus; - t (bus_open(&bus, "/tmp/example-bus", BUS_RDONLY)); - t (bus_read(&bus, callback, NULL)); - bus_close(&bus); - free(pausers); - return 0; - -fail: - perror("monitor"); - bus_close(&bus); - free(pausers); - return 1; -@} -@end example - - -@subsubheading @file{./receive-or-make-call.c} -@example -#include <bus.h> -#include <stdio.h> -#include <unistd.h> -#include <stdint.h> - -#define t(stmt) if (stmt) goto fail - -static char message[BUS_MEMORY_SIZE]; - -int main() -@{ - bus_t bus; - sprintf(message, "%ji force-pause", (intmax_t)getppid()); - /* @w{@xrm{}Yes, PPID; in this example we pretend the shell is the telephony process.@xtt{}} */ - t (bus_open(&bus, "/tmp/example-bus", BUS_WRONLY)); - t (bus_write(&bus, message, 0)); - bus_close(&bus); - return 0; - -fail: - perror("receive-or-make-call"); - bus_close(&bus); - return 1; -@} -@end example - - - -@node Timed -@section Timed - -This example shows how to use timed operations. - -First of, run make to build this example. - -To start the example run @command{./init}. When you are -done run @command{./cleanup}. - -Running instances of @command{./poll} will wait for new -messages continuously, but with one second timeouts. - -@command{./slow-poll} works like @command{./poll}, except -it will sleep for one second every time it receives -a message. - -Running instances of @command{./read} will read for ten -seconds and then time out. - -@command{./poll}, @command{./read}, and @command{./slow-poll} -will stop if the message "stop" is broadcasted. - -@command{./write} will wait for atmost a tenth of a -seconds before failing. This means that if two instances -of @command{./write} is started at the same time one of -them will fail if @command{./slow-poll} is running. - -@command{./poll}, @command{./read}, @command{./init} and -@command{./cleanup} are run without any additional -arguments. @command{./write} is run with the message -as the second argument. - - -@subsubheading @file{./Makefile} -@example -COMMANDS = init cleanup write poll read slow-poll - -all: $@{COMMANDS@} -%: %.c - $@{CC@} -Wall -Wextra -pedantic -std=c99 -lbus -o $@@ $< -clean: - -rm $@{COMMANDS@} - -.PHONY: all clean -@end example - - -@subsubheading @file{./cleanup.c} -@example -#include <bus.h> -#include <stdio.h> - -int main() -@{ - return bus_unlink("/tmp/example-bus") && (perror("cleanup"), 1); -@} -@end example - - -@subsubheading @file{./init.c} -@example -#include <bus.h> -#include <stdio.h> - -int main() -@{ - return bus_create("/tmp/example-bus", 0, NULL) && (perror("init"), 1); -@} -@end example - - -@subsubheading @file{./poll.c} -@example -#include <bus.h> -#include <stdio.h> -#include <unistd.h> -#include <string.h> -#include <errno.h> - -#define t(stmt) if (stmt) goto fail - -int main() -@{ - bus_t bus; - const char *message; - long long tick = 0; - struct timespec timeout; - t (bus_open(&bus, "/tmp/example-bus", BUS_RDONLY)); - t (bus_poll_start(&bus)); - for (;;) @{ - t (clock_gettime(CLOCK_MONOTONIC, &timeout)); - timeout.tv_sec += 1; - message = bus_poll_timed(&bus, &timeout, CLOCK_MONOTONIC); - if (message == NULL) @{ - t (errno != EAGAIN); - printf("waiting... %lli\n", ++tick); - continue; - @} - tick = 0; - message = strchr(message, ' ') + 1; - if (!strcmp(message, "stop")) - break; - printf("\033[01m%s\033[21m\n", message); - @} - t (bus_poll_stop(&bus)); - bus_close(&bus); - return 0; - -fail: - perror("poll"); - bus_poll_stop(&bus); - bus_close(&bus); - return 1; -@} -@end example - - -@subsubheading @file{./read.c} -@example -#include <bus.h> -#include <stdio.h> -#include <unistd.h> -#include <string.h> -#include <errno.h> - -#define t(stmt) if (stmt) goto fail - -static int callback(const char *message, void *user_data) -@{ - (void) user_data; - - if (message == NULL) - return 1; - - message = strchr(message, ' ') + 1; - if (!strcmp(message, "stop")) - return 0; - printf("%s\n", message); - return 1; -@} - -int main() -@{ - bus_t bus; - struct timespec timeout; - t (bus_open(&bus, "/tmp/example-bus", BUS_RDONLY)); - t (clock_gettime(CLOCK_MONOTONIC, &timeout)); - timeout.tv_sec += 10; - t (bus_read_timed(&bus, callback, NULL, &timeout, CLOCK_MONOTONIC)); - bus_close(&bus); - return 0; - -fail: - perror("poll"); - bus_poll_stop(&bus); - bus_close(&bus); - return 1; -@} -@end example - - -@subsubheading @file{./slow-poll.c} -@example -#include <bus.h> -#include <stdio.h> -#include <unistd.h> -#include <string.h> -#include <errno.h> - -#define t(stmt) if (stmt) goto fail - -int main() -@{ - bus_t bus; - const char *message; - long long tick = 0; - struct timespec timeout; - t (bus_open(&bus, "/tmp/example-bus", BUS_RDONLY)); - t (bus_poll_start(&bus)); - for (;;) @{ - t (clock_gettime(CLOCK_MONOTONIC, &timeout)); - timeout.tv_sec += 1; - message = bus_poll_timed(&bus, &timeout, CLOCK_MONOTONIC); - if (message == NULL) @{ - t (errno != EAGAIN); - printf("waiting... %lli\n", ++tick); - continue; - @} - tick = 0; - message = strchr(message, ' ') + 1; - if (!strcmp(message, "stop")) - break; - printf("\033[01m%s\033[21m\n", message); - sleep(1); - @} - t (bus_poll_stop(&bus)); - bus_close(&bus); - return 0; - -fail: - perror("poll"); - bus_poll_stop(&bus); - bus_close(&bus); - return 1; -@} -@end example - - -@subsubheading @file{./write.c} -@example -#include <bus.h> -#include <stdio.h> -#include <unistd.h> -#include <stdint.h> - -#define t(stmt) if (stmt) goto fail - -static char message[BUS_MEMORY_SIZE]; - -int main(int argc, char *argv[]) -@{ - bus_t bus; - struct timespec timeout; - if (argc < 2) @{ - fprintf(stderr, "%s: USAGE: %s message\n", argv[0], argv[0]); - return 2; - @} - sprintf(message, "0 %s", argv[1]); - t (bus_open(&bus, "/tmp/example-bus", BUS_WRONLY)); - t (clock_gettime(CLOCK_MONOTONIC, &timeout)); - timeout.tv_nsec += 100000000L; - t (bus_write_timed(&bus, message, &timeout, CLOCK_MONOTONIC)); - bus_close(&bus); - return 0; - -fail: - perror("write"); - bus_close(&bus); - return 1; -@} -@end example - - - -@node Nonblocking -@section Nonblocking - -This example shows how to use bus_poll instead of bus_read, -and how to do non-blocking polling and non-blocking writing. - -First of, run make to build this example. - -To start the example run @command{./init}. When you are done -run @command{./cleanup}. - -Running instances of @command{./poll} will check every second -if there is a new inbound message. Between these checks -@command{./write} will wait for all @command{./poll}:s to -receive the message. This means that @command{./write} blocks -while @command{./poll} sleeps. If two or more instances of -@command{./write} is started at approximately the same time, -only one will continue to write a message on the bus, the -others will fail. - -@command{./poll} will stop if the message ``stop'' is -broadcasted. - -@command{./poll}, @command{./init} and @command{./cleanup} -are run without any additional arguments. @command{./write} -is run with the message as the second argument. - - -@subsubheading @file{./Makefile} -@example -COMMANDS = init cleanup write poll - -all: $@{COMMANDS@} -%: %.c - $@{CC@} -Wall -Wextra -pedantic -std=c99 -lbus -o $@@ $< -clean: - -rm $@{COMMANDS@} - -.PHONY: all clean -@end example - - -@subsubheading @file{./cleanup.c} -@example -#include <bus.h> -#include <stdio.h> - -int main() -@{ - return bus_unlink("/tmp/example-bus") && (perror("cleanup"), 1); -@} -@end example - - -@subsubheading @file{./init.c} -@example -#include <bus.h> -#include <stdio.h> - -int main() -@{ - return bus_create("/tmp/example-bus", 0, NULL) && (perror("init"), 1); -@} -@end example - - -@subsubheading @file{./poll.c} -@example -#include <bus.h> -#include <stdio.h> -#include <unistd.h> -#include <string.h> -#include <errno.h> - -#define t(stmt) if (stmt) goto fail - -int main() -@{ - bus_t bus; - const char *message; - long long tick = 0; - t (bus_open(&bus, "/tmp/example-bus", BUS_RDONLY)); - t (bus_poll_start(&bus)); - for (;;) @{ - message = bus_poll(&bus, BUS_NOWAIT); - if (message == NULL) @{ - t (errno != EAGAIN); - printf("waiting... %lli\n", ++tick); - sleep(1); - continue; - @} - tick = 0; - message = strchr(message, ' ') + 1; - if (!strcmp(message, "stop")) - break; - printf("\033[01m%s\033[21m\n", message); - @} - t (bus_poll_stop(&bus)); - bus_close(&bus); - return 0; - -fail: - perror("poll"); - bus_poll_stop(&bus); - bus_close(&bus); - return 1; -@} -@end example - - -@subsubheading @file{./write.c} -@example -#include <bus.h> -#include <stdio.h> -#include <unistd.h> -#include <stdint.h> - -#define t(stmt) if (stmt) goto fail - -static char message[BUS_MEMORY_SIZE]; - -int main(int argc, char *argv[]) -@{ - bus_t bus; - if (argc < 2) @{ - fprintf(stderr, "%s: USAGE: %s message\n", argv[0], argv[0]); - return 2; - @} - sprintf(message, "0 %s", argv[1]); - t (bus_open(&bus, "/tmp/example-bus", BUS_WRONLY)); - t (bus_write(&bus, message, BUS_NOWAIT)); - bus_close(&bus); - return 0; - -fail: - perror("write"); - bus_close(&bus); - return 1; -@} -@end example - - - -@node Daemon-dependencies -@section Daemon-dependencies - -This example shows how bus can be used in an init system -to provide ``aggressivly'' parallel startup of daemons. - -First of, run make to build this example. - -To start the example run @command{./init}. It will print in -red export-statement you may want to run i other terminals. -You will need to select at least one daemon, for example -you can run @code{./init d-ntp}. The available pretend -daemons are: @command{d-network}, @command{d-ntp}, and -@command{d-ssh}. - -When you are done run @command{./cleanup} with @env{BUS_INIT} -exported with the value printed by @command{./init}. - - -@subsubheading @file{./Makefile} -@example -COMMANDS = announce await-ready await-started cleanup \ - init require start-daemon test-daemon - -all: $@{COMMANDS@} -%: %.c - $@{CC@} -Wall -Wextra -pedantic -std=c99 -lbus -o $@@ $< -clean: - -rm $@{COMMANDS@} - -rm -r run - -.PHONY: all clean -@end example - - -@subsubheading @file{./announce.c} -@example -#include <bus.h> -#include <stdio.h> -#include <stdlib.h> -#include <stdint.h> -#include <unistd.h> - -#define t(stmt) if (stmt) goto fail - -static char arg[4098]; - -int main(int argc, char *argv[]) -@{ - bus_t bus; - if (argc < 3) - return fprintf(stderr, "USAGE: %s state daemon", *argv), 2; - t (bus_open(&bus, getenv("BUS_INIT"), BUS_WRONLY)); - sprintf(arg, "%ji %s %s", (intmax_t)getppid(), argv[1], argv[2]); - t (bus_write(&bus, arg, 0)); - t (bus_close(&bus)); - return 0; - -fail: - perror("announce"); - return 1; -@} -@end example - - -@subsubheading @file{./await-ready.c} -@example -#include <bus.h> -#include <stdio.h> -#include <stdlib.h> -#include <stdint.h> -#include <unistd.h> -#include <string.h> -#include <sys/wait.h> - -#define t(stmt) if (stmt) goto fail - -static char arg[4098]; -static int argc; -static char **argv; -static int remaining = 0; -static char *started = NULL; -static char msg[BUS_MEMORY_SIZE]; - -static void announce_wait(pid_t pid) -@{ - bus_t bus; - int i; - t (bus_open(&bus, getenv("BUS_INIT"), BUS_WRONLY)); - for (i = 1; i < argc; i++) @{ - if (!started[i]) @{ - sprintf(arg, "%ji awaiting-ready %s", (intmax_t)pid, argv[i]); - t (bus_write(&bus, arg, 0)); - @} - @} - t (bus_close(&bus)); - return; - -fail: - perror("await-ready"); -@} - -static int callback(const char *message, void *user_data) -@{ - int i; - char *arg2; - char *arg3; - pid_t pid; - pid_t ppid; - - if (!message) @{ - ppid = getppid(); - pid = fork(); - if (pid == 0) @{ - if (fork() == 0) - announce_wait(ppid); - exit(0); - @} else @{ - (void) waitpid(pid, NULL, 0); - /* @w{@xrm{}Let's pretend everything will go swimmingly.@xtt{}} */ - @} - return 1; - @} - - strncpy(msg, message, BUS_MEMORY_SIZE - 1); - msg[BUS_MEMORY_SIZE - 1] = 0; - - arg2 = strchr(msg, ' '); - if (!arg2) - return 1; - arg3 = strchr(++arg2, ' '); - if (!arg3) - return 1; - *arg3++ = 0; - - if (strcmp(arg2, "ready")) - return 1; - - for (i = 1; i < argc; i++) - if (!started[i] && !strcmp(argv[i], arg3)) - started[i] = 1, remaining--; - - return !!remaining; - (void) user_data; -@} - -int main(int argc_, char *argv_[]) -@{ - bus_t bus; - int i; - - argc = argc_; - argv = argv_; - - if (argc < 2) - return fprintf(stderr, "USAGE: %s daemon...", *argv), 2; - t (bus_open(&bus, getenv("BUS_INIT"), BUS_RDONLY)); - started = calloc(argc, sizeof(char)); - t (started == NULL); - - started[0] = 1; - for (i = 1; i < argc; i++) @{ - sprintf(arg, "grep '^%s$'" - " <\"$@{XDG_RUNTIME_DIR@}/ready-daemons\"" - " >/dev/null", - argv[i]); - if (!WEXITSTATUS(system(arg))) - started[i] = 1; - else - remaining++; - @} - - if (remaining) - bus_read(&bus, callback, NULL); - - bus_close(&bus); - free(started); - return 0; - -fail: - perror("await-ready"); - bus_close(&bus); - free(started); - return 1; -@} -@end example - - -@subsubheading @file{./await-started.c} -@example -#include <bus.h> -#include <stdio.h> -#include <stdlib.h> -#include <stdint.h> -#include <unistd.h> -#include <string.h> -#include <sys/wait.h> - -#define t(stmt) if (stmt) goto fail - -static char arg[4098]; -static int argc; -static char **argv; -static int remaining = 0; -static char *started = NULL; -static char msg[BUS_MEMORY_SIZE]; - -static void announce_wait(pid_t pid) -@{ - bus_t bus; - int i; - t (bus_open(&bus, getenv("BUS_INIT"), BUS_WRONLY)); - for (i = 1; i < argc; i++) @{ - if (!started[i]) @{ - sprintf(arg, "%ji awaiting-started %s", (intmax_t)pid, argv[i]); - t (bus_write(&bus, arg, 0)); - @} - @} - t (bus_close(&bus)); - return; - -fail: - perror("await-started"); -@} - -static int callback(const char *message, void *user_data) -@{ - int i; - char *arg2; - char *arg3; - pid_t pid; - pid_t ppid; - - if (!message) @{ - ppid = getppid(); - pid = fork(); - if (pid == 0) @{ - if (fork() == 0) - announce_wait(ppid); - exit(0); - @} else @{ - (void) waitpid(pid, NULL, 0); - /* @w{@xrm{}Let's pretend everything will go swimmingly.@xtt{}} */ - @} - return 1; - @} - - strncpy(msg, message, BUS_MEMORY_SIZE - 1); - msg[BUS_MEMORY_SIZE - 1] = 0; - - arg2 = strchr(msg, ' '); - if (!arg2) - return 1; - arg3 = strchr(++arg2, ' '); - if (!arg3) - return 1; - *arg3++ = 0; - - if (strcmp(arg2, "started") && strcmp(arg2, "ready")) - return 1; - - for (i = 1; i < argc; i++) - if (!started[i] && !strcmp(argv[i], arg3)) - started[i] = 1, remaining--; - - return !!remaining; - (void) user_data; -@} - -int main(int argc_, char *argv_[]) -@{ - bus_t bus; - int i; - - argc = argc_; - argv = argv_; - - if (argc < 2) - return fprintf(stderr, "USAGE: %s daemon...", *argv), 2; - t (bus_open(&bus, getenv("BUS_INIT"), BUS_RDONLY)); - started = calloc(argc, sizeof(char)); - t (started == NULL); - - started[0] = 1; - for (i = 1; i < argc; i++) @{ - sprintf(arg, "grep '^%s$'" - " <\"$@{XDG_RUNTIME_DIR@}/started-daemons\"" - " >/dev/null", - argv[i]); - if (!WEXITSTATUS(system(arg))) @{ - started[i] = 1; - @} else @{ - sprintf(arg, "grep '^%s$'" - " <\"$@{XDG_RUNTIME_DIR@}/ready-daemons\"" - " >/dev/null", - argv[i]); - if (!WEXITSTATUS(system(arg))) - started[i] = 1; - else - remaining++; - @} - @} - - if (remaining) - bus_read(&bus, callback, NULL); - - bus_close(&bus); - free(started); - return 0; - -fail: - perror("await-started"); - bus_close(&bus); - free(started); - return 1; -@} -@end example - - -@subsubheading @file{./cleanup.c} -@example -#include <bus.h> -#include <stdio.h> -#include <stdlib.h> - -#define t(stmt) if (stmt) goto fail - -int main() -@{ - char *bus_address = getenv("BUS_INIT"); - if (!bus_address || !*bus_address) @{ - fprintf(stderr, "$BUS_INIT has not been set, its export statement " - "should have been printed in bold red by ./init\n"); - return 1; - @} - t (bus_unlink(bus_address)); - return 0; - -fail: - perror("cleanup"); - return 1; -@} -@end example - - -@subsubheading @file{./d-network} -@example -#!/bin/sh -PATH=.:$PATH -d=d-network - -echo $d: starting -sleep 2 -echo $d: ready -announce ready $d -@end example - - -@subsubheading @file{./d-ntp} -@example -#!/bin/sh -PATH=.:$PATH -d=d-ntp - -require d-network -echo $d: started -announce started $d -await-ready d-network -echo $d: ready -announce ready $d -@end example - - -@subsubheading @file{./d-ssh} -@example -#!/bin/sh -PATH=.:$PATH -d=d-ssh - -require d-network -echo $d: starting -sleep 1 -echo $d: started -announce started $d -sleep 1 -echo $d: ready -announce ready $d -@end example - - -@subsubheading @file{./init.c} -@example -#include <bus.h> -#include <stdio.h> -#include <stdlib.h> -#include <string.h> -#include <unistd.h> -#include <sys/wait.h> - -#define t(stmt) if (stmt) goto fail -#define _2(...) __VA_ARGS__, __VA_ARGS__ - -static char msg[BUS_MEMORY_SIZE]; -static int argc; -static char **argv; -static char arg[4098]; - -static void start_daemons() -@{ - int i; - for (i = 1; i < argc; i++) - if (fork() == 0) - execl("./start-daemon", "./start-daemon", argv[i], NULL); -@} - -static int callback(const char *message, void *user_data) -@{ - pid_t pid; - char *arg2; - char *arg3; - if (!message) @{ - pid = fork(); - t (pid == -1); - if (pid == 0) @{ - if (fork() == 0) @{ - start_daemons(); - @} - exit(0); - @} else @{ - (void) waitpid(pid, NULL, 0); - /* @w{@xrm{}Let's pretend everything will go swimmingly.@xtt{}} */ - @} - return 1; - @} - - strncpy(msg, message, BUS_MEMORY_SIZE - 1); - msg[BUS_MEMORY_SIZE - 1] = 0; - - pid = fork(); - t (pid == -1); - - if (pid == 0) @{ - if (fork() == 0) @{ - arg2 = strchr(msg, ' '); - if (arg2 == NULL) - exit(0); - arg3 = strchr(++arg2, ' '); - if (arg3 == NULL) - exit(0); - *arg3++ = 0; - if (!strcmp(arg2, "require")) @{ - execl(_2("./start-daemon"), arg3, NULL); - @} else if (!strcmp(arg2, "awaiting-started")) @{ - execl(_2("./test-daemon"), arg3, "started", NULL); - @} else if (!strcmp(arg2, "awaiting-ready") || - !strcmp(arg2, "awaiting")) @{ - execl(_2("./test-daemon"), arg3, "ready", NULL); - @} else if (!strcmp(arg2, "started")) @{ - sprintf(arg, - "grep '^%s\\$' < \"%s\" >/dev/null || echo %s >> \"%s\"", - _2(arg3, "$@{XDG_RUNTIME_DIR@}/started-daemons")); - execlp(_2("sh"), "-c", arg, NULL); - @} else if (!strcmp(arg2, "ready")) @{ - sprintf(arg, - "grep '^%s\\$' < \"%s\" >/dev/null || echo %s >> \"%s\"", - _2(arg3, "$@{XDG_RUNTIME_DIR@}/ready-daemons")); - execlp(_2("sh"), "-c", arg, NULL); - @} - @} - exit(0); - @} else @{ - (void) waitpid(pid, NULL, 0); - /* @w{@xrm{}Let's pretend everything will go swimmingly.@xtt{}} */ - @} - - return 1; - (void) user_data; - -fail: - perror("init"); - return -1; -@} - -int main(int argc_, char *argv_[]) -@{ - char *bus_address = NULL; - bus_t bus; - argv = argv_; - argc = argc_; - if (argc < 2) @{ - fprintf(stderr, "USAGE: %s daemon...\n", *argv); - return 1; - @} - t (setenv("XDG_RUNTIME_DIR", "./run", 1)); - /* @w{@xrm{}Real init systems with not have the period.@xtt{}} */ - system("mkdir -p -- \"$@{XDG_RUNTIME_DIR@}\""); - system("truncate -s 0 -- \"$@{XDG_RUNTIME_DIR@}/started-daemons\""); - system("truncate -s 0 -- \"$@{XDG_RUNTIME_DIR@}/ready-daemons\""); - t (bus_create(NULL, 1, &bus_address)); - fprintf(stderr, "\033[00;01;31mexport BUS_INIT=%s\033[00m\n", - bus_address); - fprintf(stderr, "\033[00;31mexport XDG_RUNTIME_DIR=./run\033[00m\n"); - t (setenv("BUS_INIT", bus_address, 1)); - t (bus_open(&bus, bus_address, BUS_RDONLY)); - t (bus_read(&bus, callback, NULL)); - bus_close(&bus); - free(bus_address); - return 0; - -fail: - perror("init"); - bus_close(&bus); - free(bus_address); - return 1; -@} -@end example - - -@subsubheading @file{./require.c} -@example -#include <bus.h> -#include <stdio.h> -#include <stdlib.h> -#include <stdint.h> -#include <unistd.h> - -#define t(stmt) if (stmt) goto fail - -static char arg[4098]; - -int main(int argc, char *argv[]) -@{ - bus_t bus; - int i; - if (argc < 2) - return fprintf(stderr, "USAGE: %s daemon...", *argv), 2; - t (bus_open(&bus, getenv("BUS_INIT"), BUS_WRONLY)); - - for (i = 1; i < argc; i++) @{ - sprintf(arg, "grep '^%s$' <\"%s\" >/dev/null", - argv[i], "$@{XDG_RUNTIME_DIR@}/started-daemons"); - if (WEXITSTATUS(system(arg))) @{ - sprintf(arg, "%ji require %s", (intmax_t)getppid(), argv[i]); - t (bus_write(&bus, arg, 0)); - @} - @} - - bus_close(&bus); - return 0; - -fail: - perror("require"); - bus_close(&bus); - return 1; -@} -@end example - - -@subsubheading @file{./start-daemon.c} -@example -#include <bus.h> -#include <stdio.h> -#include <stdlib.h> -#include <stdlib.h> -#include <string.h> -#include <unistd.h> - -static char arg[4098]; - -int main(int argc, char *argv[]) -@{ - if (argc != 2) @{ - fprintf(stderr, "This program should be called from ./init\n"); - return 2; - @} - - sprintf(arg, "grep '^%s$' <\"%s\" >/dev/null", - argv[1], "$@{XDG_RUNTIME_DIR@}/started-daemons"); - if (!WEXITSTATUS(system(arg))) - return 0; - sprintf(arg, "grep '^%s$' <\"%s\" >/dev/null", - argv[1], "$@{XDG_RUNTIME_DIR@}/ready-daemons"); - if (!WEXITSTATUS(system(arg))) - return 0; - - sprintf(arg, "./%s", argv[1]); - execlp(arg, arg, NULL); - perror("start-daemon"); - return 1; -@} -@end example - - -@subsubheading @file{./test-daemon.c} -@example -#include <bus.h> -#include <stdio.h> -#include <stdlib.h> -#include <string.h> - -#define t(stmt) if (stmt) goto fail - -static char arg[4098]; - -int main(int argc, char *argv[]) -@{ - bus_t bus; - if (argc != 3) @{ - fprintf(stderr, "This program should be called from ./init\n"); - return 2; - @} - -retry: - sprintf(arg, "grep '^%s$'" - " <\"$@{XDG_RUNTIME_DIR@}/%s-daemons\"" - " >/dev/null", - argv[1], argv[2]); - if (!WEXITSTATUS(system(arg))) @{ - t (bus_open(&bus, getenv("BUS_INIT"), BUS_WRONLY)); - sprintf(arg, "0 %s %s", argv[2], argv[1]); - t (bus_write(&bus, arg, 0)); - bus_close(&bus); - @} else if (!strcmp(argv[2], "started")) @{ - argv[2] = "ready"; - goto retry; - @} - return 0; - -fail: - perror("test-daemon"); - return 1; -@} -@end example - - - -@node GNU Free Documentation License -@appendix GNU Free Documentation License -@include fdl.texinfo - -@bye - diff --git a/doc/info/fdl.texinfo b/doc/info/fdl.texinfo deleted file mode 100644 index cb71f05..0000000 --- a/doc/info/fdl.texinfo +++ /dev/null @@ -1,505 +0,0 @@ -@c The GNU Free Documentation License. -@center Version 1.3, 3 November 2008 - -@c This file is intended to be included within another document, -@c hence no sectioning command or @node. - -@display -Copyright @copyright{} 2000, 2001, 2002, 2007, 2008 Free Software Foundation, Inc. -@uref{http://fsf.org/} - -Everyone is permitted to copy and distribute verbatim copies -of this license document, but changing it is not allowed. -@end display - -@enumerate 0 -@item -PREAMBLE - -The purpose of this License is to make a manual, textbook, or other -functional and useful document @dfn{free} in the sense of freedom: to -assure everyone the effective freedom to copy and redistribute it, -with or without modifying it, either commercially or noncommercially. -Secondarily, this License preserves for the author and publisher a way -to get credit for their work, while not being considered responsible -for modifications made by others. - -This License is a kind of ``copyleft'', which means that derivative -works of the document must themselves be free in the same sense. It -complements the GNU General Public License, which is a copyleft -license designed for free software. - -We have designed this License in order to use it for manuals for free -software, because free software needs free documentation: a free -program should come with manuals providing the same freedoms that the -software does. But this License is not limited to software manuals; -it can be used for any textual work, regardless of subject matter or -whether it is published as a printed book. We recommend this License -principally for works whose purpose is instruction or reference. - -@item -APPLICABILITY AND DEFINITIONS - -This License applies to any manual or other work, in any medium, that -contains a notice placed by the copyright holder saying it can be -distributed under the terms of this License. Such a notice grants a -world-wide, royalty-free license, unlimited in duration, to use that -work under the conditions stated herein. The ``Document'', below, -refers to any such manual or work. Any member of the public is a -licensee, and is addressed as ``you''. You accept the license if you -copy, modify or distribute the work in a way requiring permission -under copyright law. - -A ``Modified Version'' of the Document means any work containing the -Document or a portion of it, either copied verbatim, or with -modifications and/or translated into another language. - -A ``Secondary Section'' is a named appendix or a front-matter section -of the Document that deals exclusively with the relationship of the -publishers or authors of the Document to the Document's overall -subject (or to related matters) and contains nothing that could fall -directly within that overall subject. (Thus, if the Document is in -part a textbook of mathematics, a Secondary Section may not explain -any mathematics.) The relationship could be a matter of historical -connection with the subject or with related matters, or of legal, -commercial, philosophical, ethical or political position regarding -them. - -The ``Invariant Sections'' are certain Secondary Sections whose titles -are designated, as being those of Invariant Sections, in the notice -that says that the Document is released under this License. If a -section does not fit the above definition of Secondary then it is not -allowed to be designated as Invariant. The Document may contain zero -Invariant Sections. If the Document does not identify any Invariant -Sections then there are none. - -The ``Cover Texts'' are certain short passages of text that are listed, -as Front-Cover Texts or Back-Cover Texts, in the notice that says that -the Document is released under this License. A Front-Cover Text may -be at most 5 words, and a Back-Cover Text may be at most 25 words. - -A ``Transparent'' copy of the Document means a machine-readable copy, -represented in a format whose specification is available to the -general public, that is suitable for revising the document -straightforwardly with generic text editors or (for images composed of -pixels) generic paint programs or (for drawings) some widely available -drawing editor, and that is suitable for input to text formatters or -for automatic translation to a variety of formats suitable for input -to text formatters. A copy made in an otherwise Transparent file -format whose markup, or absence of markup, has been arranged to thwart -or discourage subsequent modification by readers is not Transparent. -An image format is not Transparent if used for any substantial amount -of text. A copy that is not ``Transparent'' is called ``Opaque''. - -Examples of suitable formats for Transparent copies include plain -ASCII without markup, Texinfo input format, La@TeX{} input -format, SGML or XML using a publicly available -DTD, and standard-conforming simple HTML, -PostScript or PDF designed for human modification. Examples -of transparent image formats include PNG, XCF and -JPG. Opaque formats include proprietary formats that can be -read and edited only by proprietary word processors, SGML or -XML for which the DTD and/or processing tools are -not generally available, and the machine-generated HTML, -PostScript or PDF produced by some word processors for -output purposes only. - -The ``Title Page'' means, for a printed book, the title page itself, -plus such following pages as are needed to hold, legibly, the material -this License requires to appear in the title page. For works in -formats which do not have any title page as such, ``Title Page'' means -the text near the most prominent appearance of the work's title, -preceding the beginning of the body of the text. - -The ``publisher'' means any person or entity that distributes copies -of the Document to the public. - -A section ``Entitled XYZ'' means a named subunit of the Document whose -title either is precisely XYZ or contains XYZ in parentheses following -text that translates XYZ in another language. (Here XYZ stands for a -specific section name mentioned below, such as ``Acknowledgements'', -``Dedications'', ``Endorsements'', or ``History''.) To ``Preserve the Title'' -of such a section when you modify the Document means that it remains a -section ``Entitled XYZ'' according to this definition. - -The Document may include Warranty Disclaimers next to the notice which -states that this License applies to the Document. These Warranty -Disclaimers are considered to be included by reference in this -License, but only as regards disclaiming warranties: any other -implication that these Warranty Disclaimers may have is void and has -no effect on the meaning of this License. - -@item -VERBATIM COPYING - -You may copy and distribute the Document in any medium, either -commercially or noncommercially, provided that this License, the -copyright notices, and the license notice saying this License applies -to the Document are reproduced in all copies, and that you add no other -conditions whatsoever to those of this License. You may not use -technical measures to obstruct or control the reading or further -copying of the copies you make or distribute. However, you may accept -compensation in exchange for copies. If you distribute a large enough -number of copies you must also follow the conditions in section 3. - -You may also lend copies, under the same conditions stated above, and -you may publicly display copies. - -@item -COPYING IN QUANTITY - -If you publish printed copies (or copies in media that commonly have -printed covers) of the Document, numbering more than 100, and the -Document's license notice requires Cover Texts, you must enclose the -copies in covers that carry, clearly and legibly, all these Cover -Texts: Front-Cover Texts on the front cover, and Back-Cover Texts on -the back cover. Both covers must also clearly and legibly identify -you as the publisher of these copies. The front cover must present -the full title with all words of the title equally prominent and -visible. You may add other material on the covers in addition. -Copying with changes limited to the covers, as long as they preserve -the title of the Document and satisfy these conditions, can be treated -as verbatim copying in other respects. - -If the required texts for either cover are too voluminous to fit -legibly, you should put the first ones listed (as many as fit -reasonably) on the actual cover, and continue the rest onto adjacent -pages. - -If you publish or distribute Opaque copies of the Document numbering -more than 100, you must either include a machine-readable Transparent -copy along with each Opaque copy, or state in or with each Opaque copy -a computer-network location from which the general network-using -public has access to download using public-standard network protocols -a complete Transparent copy of the Document, free of added material. -If you use the latter option, you must take reasonably prudent steps, -when you begin distribution of Opaque copies in quantity, to ensure -that this Transparent copy will remain thus accessible at the stated -location until at least one year after the last time you distribute an -Opaque copy (directly or through your agents or retailers) of that -edition to the public. - -It is requested, but not required, that you contact the authors of the -Document well before redistributing any large number of copies, to give -them a chance to provide you with an updated version of the Document. - -@item -MODIFICATIONS - -You may copy and distribute a Modified Version of the Document under -the conditions of sections 2 and 3 above, provided that you release -the Modified Version under precisely this License, with the Modified -Version filling the role of the Document, thus licensing distribution -and modification of the Modified Version to whoever possesses a copy -of it. In addition, you must do these things in the Modified Version: - -@enumerate A -@item -Use in the Title Page (and on the covers, if any) a title distinct -from that of the Document, and from those of previous versions -(which should, if there were any, be listed in the History section -of the Document). You may use the same title as a previous version -if the original publisher of that version gives permission. - -@item -List on the Title Page, as authors, one or more persons or entities -responsible for authorship of the modifications in the Modified -Version, together with at least five of the principal authors of the -Document (all of its principal authors, if it has fewer than five), -unless they release you from this requirement. - -@item -State on the Title page the name of the publisher of the -Modified Version, as the publisher. - -@item -Preserve all the copyright notices of the Document. - -@item -Add an appropriate copyright notice for your modifications -adjacent to the other copyright notices. - -@item -Include, immediately after the copyright notices, a license notice -giving the public permission to use the Modified Version under the -terms of this License, in the form shown in the Addendum below. - -@item -Preserve in that license notice the full lists of Invariant Sections -and required Cover Texts given in the Document's license notice. - -@item -Include an unaltered copy of this License. - -@item -Preserve the section Entitled ``History'', Preserve its Title, and add -to it an item stating at least the title, year, new authors, and -publisher of the Modified Version as given on the Title Page. If -there is no section Entitled ``History'' in the Document, create one -stating the title, year, authors, and publisher of the Document as -given on its Title Page, then add an item describing the Modified -Version as stated in the previous sentence. - -@item -Preserve the network location, if any, given in the Document for -public access to a Transparent copy of the Document, and likewise -the network locations given in the Document for previous versions -it was based on. These may be placed in the ``History'' section. -You may omit a network location for a work that was published at -least four years before the Document itself, or if the original -publisher of the version it refers to gives permission. - -@item -For any section Entitled ``Acknowledgements'' or ``Dedications'', Preserve -the Title of the section, and preserve in the section all the -substance and tone of each of the contributor acknowledgements and/or -dedications given therein. - -@item -Preserve all the Invariant Sections of the Document, -unaltered in their text and in their titles. Section numbers -or the equivalent are not considered part of the section titles. - -@item -Delete any section Entitled ``Endorsements''. Such a section -may not be included in the Modified Version. - -@item -Do not retitle any existing section to be Entitled ``Endorsements'' or -to conflict in title with any Invariant Section. - -@item -Preserve any Warranty Disclaimers. -@end enumerate - -If the Modified Version includes new front-matter sections or -appendices that qualify as Secondary Sections and contain no material -copied from the Document, you may at your option designate some or all -of these sections as invariant. To do this, add their titles to the -list of Invariant Sections in the Modified Version's license notice. -These titles must be distinct from any other section titles. - -You may add a section Entitled ``Endorsements'', provided it contains -nothing but endorsements of your Modified Version by various -parties---for example, statements of peer review or that the text has -been approved by an organization as the authoritative definition of a -standard. - -You may add a passage of up to five words as a Front-Cover Text, and a -passage of up to 25 words as a Back-Cover Text, to the end of the list -of Cover Texts in the Modified Version. Only one passage of -Front-Cover Text and one of Back-Cover Text may be added by (or -through arrangements made by) any one entity. If the Document already -includes a cover text for the same cover, previously added by you or -by arrangement made by the same entity you are acting on behalf of, -you may not add another; but you may replace the old one, on explicit -permission from the previous publisher that added the old one. - -The author(s) and publisher(s) of the Document do not by this License -give permission to use their names for publicity for or to assert or -imply endorsement of any Modified Version. - -@item -COMBINING DOCUMENTS - -You may combine the Document with other documents released under this -License, under the terms defined in section 4 above for modified -versions, provided that you include in the combination all of the -Invariant Sections of all of the original documents, unmodified, and -list them all as Invariant Sections of your combined work in its -license notice, and that you preserve all their Warranty Disclaimers. - -The combined work need only contain one copy of this License, and -multiple identical Invariant Sections may be replaced with a single -copy. If there are multiple Invariant Sections with the same name but -different contents, make the title of each such section unique by -adding at the end of it, in parentheses, the name of the original -author or publisher of that section if known, or else a unique number. -Make the same adjustment to the section titles in the list of -Invariant Sections in the license notice of the combined work. - -In the combination, you must combine any sections Entitled ``History'' -in the various original documents, forming one section Entitled -``History''; likewise combine any sections Entitled ``Acknowledgements'', -and any sections Entitled ``Dedications''. You must delete all -sections Entitled ``Endorsements.'' - -@item -COLLECTIONS OF DOCUMENTS - -You may make a collection consisting of the Document and other documents -released under this License, and replace the individual copies of this -License in the various documents with a single copy that is included in -the collection, provided that you follow the rules of this License for -verbatim copying of each of the documents in all other respects. - -You may extract a single document from such a collection, and distribute -it individually under this License, provided you insert a copy of this -License into the extracted document, and follow this License in all -other respects regarding verbatim copying of that document. - -@item -AGGREGATION WITH INDEPENDENT WORKS - -A compilation of the Document or its derivatives with other separate -and independent documents or works, in or on a volume of a storage or -distribution medium, is called an ``aggregate'' if the copyright -resulting from the compilation is not used to limit the legal rights -of the compilation's users beyond what the individual works permit. -When the Document is included in an aggregate, this License does not -apply to the other works in the aggregate which are not themselves -derivative works of the Document. - -If the Cover Text requirement of section 3 is applicable to these -copies of the Document, then if the Document is less than one half of -the entire aggregate, the Document's Cover Texts may be placed on -covers that bracket the Document within the aggregate, or the -electronic equivalent of covers if the Document is in electronic form. -Otherwise they must appear on printed covers that bracket the whole -aggregate. - -@item -TRANSLATION - -Translation is considered a kind of modification, so you may -distribute translations of the Document under the terms of section 4. -Replacing Invariant Sections with translations requires special -permission from their copyright holders, but you may include -translations of some or all Invariant Sections in addition to the -original versions of these Invariant Sections. You may include a -translation of this License, and all the license notices in the -Document, and any Warranty Disclaimers, provided that you also include -the original English version of this License and the original versions -of those notices and disclaimers. In case of a disagreement between -the translation and the original version of this License or a notice -or disclaimer, the original version will prevail. - -If a section in the Document is Entitled ``Acknowledgements'', -``Dedications'', or ``History'', the requirement (section 4) to Preserve -its Title (section 1) will typically require changing the actual -title. - -@item -TERMINATION - -You may not copy, modify, sublicense, or distribute the Document -except as expressly provided under this License. Any attempt -otherwise to copy, modify, sublicense, or distribute it is void, and -will automatically terminate your rights under this License. - -However, if you cease all violation of this License, then your license -from a particular copyright holder is reinstated (a) provisionally, -unless and until the copyright holder explicitly and finally -terminates your license, and (b) permanently, if the copyright holder -fails to notify you of the violation by some reasonable means prior to -60 days after the cessation. - -Moreover, your license from a particular copyright holder is -reinstated permanently if the copyright holder notifies you of the -violation by some reasonable means, this is the first time you have -received notice of violation of this License (for any work) from that -copyright holder, and you cure the violation prior to 30 days after -your receipt of the notice. - -Termination of your rights under this section does not terminate the -licenses of parties who have received copies or rights from you under -this License. If your rights have been terminated and not permanently -reinstated, receipt of a copy of some or all of the same material does -not give you any rights to use it. - -@item -FUTURE REVISIONS OF THIS LICENSE - -The Free Software Foundation may publish new, revised versions -of the GNU Free Documentation License from time to time. Such new -versions will be similar in spirit to the present version, but may -differ in detail to address new problems or concerns. See -@uref{http://www.gnu.org/copyleft/}. - -Each version of the License is given a distinguishing version number. -If the Document specifies that a particular numbered version of this -License ``or any later version'' applies to it, you have the option of -following the terms and conditions either of that specified version or -of any later version that has been published (not as a draft) by the -Free Software Foundation. If the Document does not specify a version -number of this License, you may choose any version ever published (not -as a draft) by the Free Software Foundation. If the Document -specifies that a proxy can decide which future versions of this -License can be used, that proxy's public statement of acceptance of a -version permanently authorizes you to choose that version for the -Document. - -@item -RELICENSING - -``Massive Multiauthor Collaboration Site'' (or ``MMC Site'') means any -World Wide Web server that publishes copyrightable works and also -provides prominent facilities for anybody to edit those works. A -public wiki that anybody can edit is an example of such a server. A -``Massive Multiauthor Collaboration'' (or ``MMC'') contained in the -site means any set of copyrightable works thus published on the MMC -site. - -``CC-BY-SA'' means the Creative Commons Attribution-Share Alike 3.0 -license published by Creative Commons Corporation, a not-for-profit -corporation with a principal place of business in San Francisco, -California, as well as future copyleft versions of that license -published by that same organization. - -``Incorporate'' means to publish or republish a Document, in whole or -in part, as part of another Document. - -An MMC is ``eligible for relicensing'' if it is licensed under this -License, and if all works that were first published under this License -somewhere other than this MMC, and subsequently incorporated in whole -or in part into the MMC, (1) had no cover texts or invariant sections, -and (2) were thus incorporated prior to November 1, 2008. - -The operator of an MMC Site may republish an MMC contained in the site -under CC-BY-SA on the same site at any time before August 1, 2009, -provided the MMC is eligible for relicensing. - -@end enumerate - -@page -@heading ADDENDUM: How to use this License for your documents - -To use this License in a document you have written, include a copy of -the License in the document and put the following copyright and -license notices just after the title page: - -@smallexample -@group - Copyright (C) @var{year} @var{your name}. - Permission is granted to copy, distribute and/or modify this document - under the terms of the GNU Free Documentation License, Version 1.3 - or any later version published by the Free Software Foundation; - with no Invariant Sections, no Front-Cover Texts, and no Back-Cover - Texts. A copy of the license is included in the section entitled ``GNU - Free Documentation License''. -@end group -@end smallexample - -If you have Invariant Sections, Front-Cover Texts and Back-Cover Texts, -replace the ``with@dots{}Texts.''@: line with this: - -@smallexample -@group - with the Invariant Sections being @var{list their titles}, with - the Front-Cover Texts being @var{list}, and with the Back-Cover Texts - being @var{list}. -@end group -@end smallexample - -If you have Invariant Sections without Cover Texts, or some other -combination of the three, merge those two alternatives to suit the -situation. - -If your document contains nontrivial examples of program code, we -recommend releasing these examples in parallel under your choice of -free software license, such as the GNU General Public License, -to permit their use in free software. - -@c Local Variables: -@c ispell-local-pdict: "ispell-dict" -@c End: diff --git a/doc/man/bus-broadcast.1 b/doc/man/bus-broadcast.1 deleted file mode 100644 index a4dc76c..0000000 --- a/doc/man/bus-broadcast.1 +++ /dev/null @@ -1,35 +0,0 @@ -.TH BUS-BROADCAST 1 BUS-%VERSION% -.SH NAME -bus broadcast - Broadcast a message on a bus -.SH SYNOPSIS -.B bus broadcast -.IR [options] -[--] -.IR pathname -.IR message -.SH DESCRIPTION -Broadcast \fImessage\fP on the bus associated with \fIpathname\fP. -.SH OPTIONS -.TP -.B \-n -Fail if another process is attempting to broadcast on the bus. -.SH EXIT STATUS -.TP -0 -The command was successful. -.TP -1 -The command failed. -.TP -2 -The command is not recognised. -.SH SEE ALSO -.BR bus (5) -.SH AUTHORS -Principal author, Mattias Andrée. See the LICENSE file for the full -list of authors. -.SH LICENSE -MIT/X Consortium License. -.SH BUGS -Please report bugs to https://github.com/maandree/bus/issues or to -maandree@member.fsf.org diff --git a/doc/man/bus-chgrp.1 b/doc/man/bus-chgrp.1 deleted file mode 100644 index d825e32..0000000 --- a/doc/man/bus-chgrp.1 +++ /dev/null @@ -1,38 +0,0 @@ -.TH BUS-CHGRP 1 BUS-%VERSION% -.SH NAME -bus chgrp - Change group ownership of a bus -.SH SYNOPSIS -.B bus chgrp -[--] -.IR group -.IR pathname -.SH DESCRIPTION -Change the group, that owns a bus with an associated \fIpathname\fP, -to the specified \fIgroup\fP. The \fIgroup\fP can be specified either -with a GID or with a group name. -.PP -The current ownership of a bus can be retrieved by running -.BR stat (1) -over the \fIpathname\fP of the bus. -.SH EXIT STATUS -.TP -0 -The command was successful. -.TP -1 -The command failed. -.TP -2 -The command is not recognised. -.SH SEE ALSO -.BR bus-chown (1), -.BR bus-chmod (1), -.BR stat (1) -.SH AUTHORS -Principal author, Mattias Andrée. See the LICENSE file for the full -list of authors. -.SH LICENSE -MIT/X Consortium License. -.SH BUGS -Please report bugs to https://github.com/maandree/bus/issues or to -maandree@member.fsf.org diff --git a/doc/man/bus-chmod.1 b/doc/man/bus-chmod.1 deleted file mode 100644 index 3a44423..0000000 --- a/doc/man/bus-chmod.1 +++ /dev/null @@ -1,49 +0,0 @@ -.TH BUS-CHMOD 1 BUS-%VERSION% -.SH NAME -bus chmod - Change permissions on a bus -.SH SYNOPSIS -.B bus chmod -[--] -.IR permissions -.IR pathname -.SH DESCRIPTION -Change who have access to a bus with an associated \fIpathname\fP. -In the \fIpermissions\fP, the owner, the group, and others (not -in group) are represented by the symbols \fBu\fP, \fBg\fP, and -\fBo\fP, respectively. The \fIpermissions\fP string is imagined -to have always be prefixed with an \fB=\fP. This symbols means -that all user classes list after it, and only those classes, as -permission to use the bus. Similarly the symbols \fB+\fP and -\fB\-\fP can be used to grant and revoke access, respectively. -The symbols \fB=\fP, \fB+\fP, and \fB\-\fP can be mixed, and are -interpreted from left to right. Alternatively the \fIpermissions\fP -string can be a octal number, where the owner is represented by any -bit in 700 (100, 200, or 400, or any combination thereof), the -group is represented by any bit in 70, and others (not in the group) -is represented by any bit in 7. -.PP -The current permissions of a bus can be retrieved by running -.BR stat (1) -over the \fIpathname\fP of the bus. -.SH EXIT STATUS -.TP -0 -The command was successful. -.TP -1 -The command failed. -.TP -2 -The command is not recognised. -.SH SEE ALSO -.BR bus-chown (1), -.BR bus-chgrp (1), -.BR stat (1) -.SH AUTHORS -Principal author, Mattias Andrée. See the LICENSE file for the full -list of authors. -.SH LICENSE -MIT/X Consortium License. -.SH BUGS -Please report bugs to https://github.com/maandree/bus/issues or to -maandree@member.fsf.org diff --git a/doc/man/bus-chown.1 b/doc/man/bus-chown.1 deleted file mode 100644 index 24487a1..0000000 --- a/doc/man/bus-chown.1 +++ /dev/null @@ -1,41 +0,0 @@ -.TH BUS-CHOWN 1 BUS-%VERSION% -.SH NAME -bus chown - Change ownership of a bus -.SH SYNOPSIS -.B bus chown -[--] -.IR owner[:group] -.IR pathname -.SH DESCRIPTION -Change the owner, that owns a bus with an associated \fIpathname\fP, -to the specified \fIowner\fP. The \fIowner\fP can be specified either -with a UID or with a user name. If a \fIgroup\fP is specified, the -bus's owner-group will be set to that \fIgroup\fP, otherwise the group -will remain unchanged. The \fIgroup\fP can be specified either with -a GID or with a group name. -.PP -The current ownership of a bus can be retrieved by running -.BR stat (1) -over the \fIpathname\fP of the bus. -.SH EXIT STATUS -.TP -0 -The command was successful. -.TP -1 -The command failed. -.TP -2 -The command is not recognised. -.SH SEE ALSO -.BR bus-chgrp (1), -.BR bus-chmod (1), -.BR stat (1) -.SH AUTHORS -Principal author, Mattias Andrée. See the LICENSE file for the full -list of authors. -.SH LICENSE -MIT/X Consortium License. -.SH BUGS -Please report bugs to https://github.com/maandree/bus/issues or to -maandree@member.fsf.org diff --git a/doc/man/bus-create.1 b/doc/man/bus-create.1 deleted file mode 100644 index 91041cf..0000000 --- a/doc/man/bus-create.1 +++ /dev/null @@ -1,37 +0,0 @@ -.TH BUS-CREATE 1 BUS-%VERSION% -.SH NAME -bus create - Create a bus -.SH SYNOPSIS -.B bus create -.IR [options] -[--] -.IR [pathname] -.SH DESCRIPTION -Create a bus with an associated \fIpathname\fP. If \fIpathname\fP -is omitted, a random pathname in \fI$XDG_RUNTIME_DIR/bus\fP will be -created and printed to stdout. -.SH OPTIONS -.TP -.B \-x -Fail if the \fIpathname\fP already exists. -.SH EXIT STATUS -.TP -0 -The command was successful. -.TP -1 -The command failed. -.TP -2 -The command is not recognised. -.SH SEE ALSO -.BR bus (5), -.BR bus-remove (1) -.SH AUTHORS -Principal author, Mattias Andrée. See the LICENSE file for the full -list of authors. -.SH LICENSE -MIT/X Consortium License. -.SH BUGS -Please report bugs to https://github.com/maandree/bus/issues or to -maandree@member.fsf.org diff --git a/doc/man/bus-listen.1 b/doc/man/bus-listen.1 deleted file mode 100644 index 4977ce5..0000000 --- a/doc/man/bus-listen.1 +++ /dev/null @@ -1,32 +0,0 @@ -.TH BUS-LISTEN 1 BUS-%VERSION% -.SH NAME -bus listen - Listen for new messages on a bus -.SH SYNOPSIS -.B bus listen -[--] -.IR pathname -.IR command -.SH DESCRIPTION -Listen for new messages on the bus associated with \fIpathname\fP. Once -a message is received, \fIcommand\fP will be spawned with \fI$msg\fP set -to the received message. POSIX shell syntax applies to \fIcommand\fP. -.SH EXIT STATUS -.TP -0 -The command was successful. -.TP -1 -The command failed. -.TP -2 -The command is not recognised. -.SH SEE ALSO -.BR bus (5) -.SH AUTHORS -Principal author, Mattias Andrée. See the LICENSE file for the full -list of authors. -.SH LICENSE -MIT/X Consortium License. -.SH BUGS -Please report bugs to https://github.com/maandree/bus/issues or to -maandree@member.fsf.org diff --git a/doc/man/bus-remove.1 b/doc/man/bus-remove.1 deleted file mode 100644 index 95e805c..0000000 --- a/doc/man/bus-remove.1 +++ /dev/null @@ -1,29 +0,0 @@ -.TH BUS-REMOVE 1 BUS-%VERSION% -.SH NAME -bus remove - Remove a bus -.SH SYNOPSIS -.B bus remove -[--] -.IR pathname -.SH DESCRIPTION -Remove the bus associated with \fIpathname\fP. -.SH EXIT STATUS -.TP -0 -The command was successful. -.TP -1 -The command failed. -.TP -2 -The command is not recognised. -.SH SEE ALSO -.BR bus (5) -.SH AUTHORS -Principal author, Mattias Andrée. See the LICENSE file for the full -list of authors. -.SH LICENSE -MIT/X Consortium License. -.SH BUGS -Please report bugs to https://github.com/maandree/bus/issues or to -maandree@member.fsf.org diff --git a/doc/man/bus-wait.1 b/doc/man/bus-wait.1 deleted file mode 100644 index 4231cd0..0000000 --- a/doc/man/bus-wait.1 +++ /dev/null @@ -1,33 +0,0 @@ -.TH BUS-WAIT 1 BUS-%VERSION% -.SH NAME -bus wait - Listen for a new message on a bus -.SH SYNOPSIS -.B bus wait -[--] -.IR pathname -.IR command -.SH DESCRIPTION -Listen for a new message on the bus associated with \fIpathname\fP, stop -listening once a message has been received. Once a message is received, -\fIcommand\fP will be spawned with \fI$msg\fP set to the received -message. POSIX shell syntax applies to \fIcommand\fP. -.SH EXIT STATUS -.TP -0 -The command was successful. -.TP -1 -The command failed. -.TP -2 -The command is not recognised. -.SH SEE ALSO -.BR bus (5) -.SH AUTHORS -Principal author, Mattias Andrée. See the LICENSE file for the full -list of authors. -.SH LICENSE -MIT/X Consortium License. -.SH BUGS -Please report bugs to https://github.com/maandree/bus/issues or to -maandree@member.fsf.org diff --git a/doc/man/bus.1 b/doc/man/bus.1 deleted file mode 100644 index afb3925..0000000 --- a/doc/man/bus.1 +++ /dev/null @@ -1,77 +0,0 @@ -.TH BUS 1 BUS-%VERSION% -.SH NAME -bus - A simple daemonless system for broadcasting messages locally -.SH SYNOPSIS -.B bus -.IR command -.IR argument\ ... -.SH COMMANDS -.TP -.B create -Create a bus, see -.BR bus-create (1) -for further details. -.TP -.B remove -Remove a bus, see -.BR bus-remove (1) -for further details. -.TP -.B listen -Listen for new message on a bus, see -.BR bus-listen (1) -for further details. -.TP -.B wait -Listen for one new message only on a bus, see -.BR bus-wait (1) -for further details. -.TP -.B broadcast -Broadcast a message on a bus, see -.BR bus-broadcast (1) -for further details. -.TP -.B chmod -Change permissions on a bus, see -.BR bus-chmod (1) -for further details. -.TP -.B chown -Change ownership of a bus, see -.BR bus-chown (1) -for further details. -.TP -.B chgrp -Change group ownership of a bus, see -.BR bus-chgrp (1) -for further details. -.SH EXIT STATUS -.TP -0 -The command was successful. -.TP -1 -The command failed. -.TP -2 -The command is not recognised. -.SH SEE ALSO -.BR bus-create (1), -.BR bus-remove (1), -.BR bus-listen (1), -.BR bus-wait (1), -.BR bus-broadcast (1), -.BR bus-chmod (1), -.BR bus-chown (1), -.BR bus-chgrp (1), -.BR bus (5), -.BR libbus (7) -.SH AUTHORS -Principal author, Mattias Andrée. See the LICENSE file for the full -list of authors. -.SH LICENSE -MIT/X Consortium License. -.SH BUGS -Please report bugs to https://github.com/maandree/bus/issues or to -maandree@member.fsf.org diff --git a/doc/man/bus.5 b/doc/man/bus.5 deleted file mode 100644 index 0a5de7e..0000000 --- a/doc/man/bus.5 +++ /dev/null @@ -1,50 +0,0 @@ -.TH BUS 5 BUS-%VERSION% -.SH NAME -bus - A simple daemonless system for broadcasting messages locally -.SH DESCRIPTION -\fBbus\fP is a simple interprocess communication system for broadcasting -messages to other processes on the same machine. \fBbus\fP does not use -any daemon. Instead, all communication and synchronisation is managed -using System V (XSI) semaphores and System V (XSI) shared memory. -.PP -The command \fBbus create\fP can be used to create new buses. By -convention, buses should be stored in \fI$XDG_RUNTIME_DIR/bus\fP, this is -what \fBbus create\fP does if no pathname is given. The pathname of the -bus should be tracked using \fIBUS_X\fP, where \fIX\fP is replaced with -either: -.TP -.B GENERIC -For the bus used in generic cases. That is all but the cases of the -buses listed below. -.TP -.B AUDIO -For the bus used in with the audio subsystem is involved. -.TP -.B VIDEO -For the bus used in with the video subsystem is involved. -.TP -.B INPUT -For the bus used in with the input subsystem is involved. -.TP -.B FILES -For the bus used in with the storage subsystem is involved. -.PP -Messages broadcasted on a bus cannot be longer than 2047 bytes, -excluding NULL termination. Message should be encoded in UTF-8, -and most not contain the NULL character. -.PP -Broadcasted message should start with the process ID, or 0 if ephemeral, -whence the message originated, followed by a single regular space. -.SH SEE ALSO -.BR bus (1), -.BR libbus (7), -.BR semop (2), -.BR shmop (2) -.SH AUTHORS -Principal author, Mattias Andrée. See the LICENSE file for the full -list of authors. -.SH LICENSE -MIT/X Consortium License. -.SH BUGS -Please report bugs to https://github.com/maandree/bus/issues or to -maandree@member.fsf.org diff --git a/doc/man/bus_chmod.3 b/doc/man/bus_chmod.3 deleted file mode 100644 index c2ac3f9..0000000 --- a/doc/man/bus_chmod.3 +++ /dev/null @@ -1,64 +0,0 @@ -.TH BUS_CHMOD 3 BUS-%VERSION% -.SH NAME -bus_chmod - Change bus mode bits -.SH SYNOPSIS -.LP -.nf -#include <bus.h> -.P -int bus_chmod(const char *\fIfile\fP, mode_t \fImode\fP); -.fi -.SH DESCRIPTION -The -.BR bus_chmod () -function gives access to the bus associated with \fIfile\fP -according to the following rules: -.TP -* -If (\fImode\fP &S_IRWXU) the owner should be given full access to the -bus. Otherwise the owner should have no access. -.TP -* -If (\fImode\fP &S_IRWXG) the group should be given read and write -access to the bus. Otherwise the group should have no access. -.TP -* -If (\fImode\fP &S_IRWXO) others (except the group) should be given -read and write access to the bus. Otherwise others should have no -access. -.PP -The current permissions of a bus can be retrieved by running -.BR stat (3) -over the \fIpathname\fP of the bus. -.SH RETURN VALUES -Upon successful completion, the function returns 0. Otherwise the -function returns -1 and sets \fIerrno\fP to indicate the error. -.SH ERRORS -The -.BR bus_chown (3) -function may fail and set \fIerrno\fP to any of the -errors specified for -.BR bus_open (3), -.BR chmod (3), -.BR semget (3), -.BR shmget (3) -and -.BR shmctl (3) -as well as any errors specified for the \fIIPC_STAT\fP and -\fIIPC_SET\fP commands for -.BR semctl (3). -.SH SEE ALSO -.BR bus-create (1), -.BR bus (5), -.BR libbus (7), -.BR bus_open (3), -.BR bus_read (3), -.BR stat (3) -.SH AUTHORS -Principal author, Mattias Andrée. See the LICENSE file for the full -list of authors. -.SH LICENSE -MIT/X Consortium License. -.SH BUGS -Please report bugs to https://github.com/maandree/bus/issues or to -maandree@member.fsf.org diff --git a/doc/man/bus_chown.3 b/doc/man/bus_chown.3 deleted file mode 100644 index c047d83..0000000 --- a/doc/man/bus_chown.3 +++ /dev/null @@ -1,51 +0,0 @@ -.TH BUS_CHOWN 3 BUS-%VERSION% -.SH NAME -bus_chown - Change bus owner and group -.SH SYNOPSIS -.LP -.nf -#include <bus.h> -.P -int bus_chown(const char *\fIfile\fP, uid_t \fIowner\fP, gid_t \fIgroup\fP); -.fi -.SH DESCRIPTION -The -.BR bus_chown () -function changes the owner and the group of the bus associated with -\fIfile\fP to the \fIowner\fP and \fIgroup\fP, respectively. -.PP -The current ownership of a bus can be retrieved by running -.BR stat (3) -over the \fIpathname\fP of the bus. -.SH RETURN VALUES -Upon successful completion, the function returns 0. Otherwise the -function returns -1 and sets \fIerrno\fP to indicate the error. -.SH ERRORS -The -.BR bus_chown (3) -function may fail and set \fIerrno\fP to any of the -errors specified for -.BR bus_open (3), -.BR chown (3), -.BR semget (3), -.BR shmget (3) -and -.BR shmctl (3) -as well as any errors specified for the \fIIPC_STAT\fP and -\fIIPC_SET\fP commands for -.BR semctl (3). -.SH SEE ALSO -.BR bus-create (1), -.BR bus (5), -.BR libbus (7), -.BR bus_open (3), -.BR bus_read (3), -.BR stat (3) -.SH AUTHORS -Principal author, Mattias Andrée. See the LICENSE file for the full -list of authors. -.SH LICENSE -MIT/X Consortium License. -.SH BUGS -Please report bugs to https://github.com/maandree/bus/issues or to -maandree@member.fsf.org diff --git a/doc/man/bus_close.3 b/doc/man/bus_close.3 deleted file mode 100644 index dc35e6b..0000000 --- a/doc/man/bus_close.3 +++ /dev/null @@ -1,36 +0,0 @@ -.TH BUS_CLOSE 3 BUS-%VERSION% -.SH NAME -bus_close - Close a bus -.SH SYNOPSIS -.LP -.nf -#include <bus.h> -.P -int bus_close(bus_t *\fIbus\fP); -.fi -.SH DESCRIPTION -The -.BR bus_close () -function disposes of resources allocated to the process, as referenced -in the \fIbus\fP argument. -.SH RETURN VALUES -Upon successful completion, the function returns 0. Otherwise the -function returns -1 and sets \fIerrno\fP to indicate the error. -.SH ERRORS -.TP -.B EINVAL -The bus does not exist. -.SH SEE ALSO -.BR bus-create (1), -.BR bus (5), -.BR libbus (7), -.BR bus_open (3), -.BR bus_unlink (3) -.SH AUTHORS -Principal author, Mattias Andrée. See the LICENSE file for the full -list of authors. -.SH LICENSE -MIT/X Consortium License. -.SH BUGS -Please report bugs to https://github.com/maandree/bus/issues or to -maandree@member.fsf.org diff --git a/doc/man/bus_create.3 b/doc/man/bus_create.3 deleted file mode 100644 index 88e6efe..0000000 --- a/doc/man/bus_create.3 +++ /dev/null @@ -1,63 +0,0 @@ -.TH BUS_CREATE 3 BUS-%VERSION% -.SH NAME -bus_create - Create a new bus -.SH SYNOPSIS -.LP -.nf -#include <bus.h> -.P -int bus_create(const char *\fIfile\fP, int \fIflags\fP, char **\fIout_file\fP); -.fi -.SH DESCRIPTION -The -.BR bus_create () -function creates a bus with the asscoiated pathname specifed by the -value of the parameter \fIfile\fP. If \fIfile\fP is \fINULL\fP a random -pathname is selected. This pathname adheres to the convention set forth -by -.BR bus (5). -.PP -If \fIfile\fP is not \fINULL\fP the -.BR bus_create () -function fails if the file already exists if \fIflags\fP contains -\fIBUS_EXCL\fP. Otherwise if \fIfile\fP is not \fINULL\fP, the -.BR bus_create () -function does nothing if the file already exists. -.PP -If \fIflags\fP contains \fIBUS_INTR\fP, the function fails if it is -interrupted. -.PP -Unless \fIout_file\fP is \fINULL\fP, the pathname of the bus should be -stored in a new char array stored in \fI*out_file\fP. The caller must -free the allocated stored in \fI*out_file\fP. -.SH RETURN VALUES -Upon successful completion, the function returns 0. Otherwise the -function return -1 with \fIerrno\fP set to indicate the error. -.SH ERRORS -.TP -.B ENOMEM -The process cannot allocate more memory. -.PP -The -.BR bus_create (3) -function may also fail and set \fIerrno\fP to any -of the errors specified for the routines -.BR open (2) -and -.BR write (2). -.SH SEE ALSO -.BR bus-create (1), -.BR bus (5), -.BR libbus (7), -.BR bus_unlink (3), -.BR bus_open (3), -.BR open (2), -.BR write (2) -.SH AUTHORS -Principal author, Mattias Andrée. See the LICENSE file for the full -list of authors. -.SH LICENSE -MIT/X Consortium License. -.SH BUGS -Please report bugs to https://github.com/maandree/bus/issues or to -maandree@member.fsf.org diff --git a/doc/man/bus_open.3 b/doc/man/bus_open.3 deleted file mode 100644 index 683ae9b..0000000 --- a/doc/man/bus_open.3 +++ /dev/null @@ -1,67 +0,0 @@ -.TH BUS_OPEN 3 BUS-%VERSION% -.SH NAME -bus_open - Open a bus -.SH SYNOPSIS -.LP -.nf -#include <bus.h> -.P -int bus_open(bus_t *\fIbus\fP, const char *\fIfile\fP, int \fIflags\fP); -.fi -.SH DESCRIPTION -The -.BR bus_open () -function acquires resources required for the process to use the bus -associated with the filename stored in \fIfile\fP. The function also -stores the resources in \fIbus\fP for use by other -.BR bus -functions. -.PP -Values for \fIflags\fP are constructed by a bitwise inclusive OR of -flags from the following list. -.TP -.B BUS_RDONLY -The process will only be using the bus for receiving messages. -.TP -.B BUS_WRONLY -The process will only be using the bus for sending messages. -.TP -.B BUS_RDWR -The process will use the bus for both receiving and sending messages. -.SH RETURN VALUES -Upon successful completion the function returns 0. Otherwise the -function returns -1 and set \fIerrno\fP to indicate the error. -.SH ERRORS -.TP -.B ENOMEM -The process cannot allocate more memory. -.TP -.B EACCES -Operation permission is denied to the calling process. -.TP -.B EINVAL -The described bus does not exist. -.PP -The -.BR bus_open () -function may also fail and set \fIerrno\fP to any of the errors -specified for the routine -.BR open (2). -.SH SEE ALSO -.BR bus-create (1), -.BR bus (5), -.BR libbus (7), -.BR bus_close (3), -.BR bus_unlink (3), -.BR bus_write (3), -.BR bus_read (3), -.BR bus_poll (3), -.BR open (2) -.SH AUTHORS -Principal author, Mattias Andrée. See the LICENSE file for the full -list of authors. -.SH LICENSE -MIT/X Consortium License. -.SH BUGS -Please report bugs to https://github.com/maandree/bus/issues or to -maandree@member.fsf.org diff --git a/doc/man/bus_poll.3 b/doc/man/bus_poll.3 deleted file mode 100644 index 95271ca..0000000 --- a/doc/man/bus_poll.3 +++ /dev/null @@ -1,87 +0,0 @@ -.TH BUS_POLL 3 BUS-%VERSION% -.SH NAME -bus_poll_start, bus_poll_stop, bus_poll, bus_poll_timed - Wait a message to be broadcasted -.SH SYNOPSIS -.LP -.nf -#include <bus.h> -.P -int bus_poll_start(bus_t *\fIbus\fP); -int bus_poll_stop(const bus_t *\fIbus\fP); -const char *bus_poll(bus_t *\fIbus\fP, int \fIflags\fP); -const char *bus_poll_timed(bus_t *\fIbus\fP, const struct timespec *\fItimeout\fP, clockid_t \fIclockid\fP); -.fi -.SH DESCRIPTION -The -.BR bus_poll () -function waits for a message to be broadcasted on the \fIbus\fP, and return -the message it receives. The function fails if (\fIflags\fP &BUS_NOWAIT) -and there is not already a message waiting on the bus. Received messages -shall be copied and parsed, and acted upon, in a separate thread, and -.BR bus_poll () -or -.BR bus_poll_stop () -called again as soon as possible. -.PP -The -.BR bus_poll_start () -funcion must be called before -.BR bus_poll () -is called for the first time. When the process is done listening on the -bus it must call the -.BR bus_poll_stop () -function. -.PP -The -.BR bus_poll_timed () -function behaves like -.BR bus_poll (), -except if it is not able to read a message within the specified time, -it will fail and set \fIerrno\fP to \fBEAGAIN\fP. The time is specified -as an absolute time using the parameter \fItimeout\fP. The behaviour is -unspecified if \fItimeout\fP is \fINULL\fP. \fItimeout\fP is measured -with the clock whose ID is specified by the \fIclockid\fP parameter. This -clock must be a predicitable clock. -.SH RETURN VALUES -Upon successful completion, the functions -.BR bus_poll_start () -and -.BR bus_poll_stop () -returns 0. Otherwise the functions returns -1 and sets \fIerrno\fP to -indicate the error. -.PP -Upon successful completion, the functions -.BR bus_poll () -and -.BR bus_poll_timed () -returns the received message. Otherwise the function returns \fINULL\fP -and sets \fIerrno\fP to indicate the error. -.SH ERRORS -The -.BR bus_poll (3), -.BR bus_poll_start (3) -and -.BR bus_poll_stop (3) -functions may fail and set \fIerrno\fP to any of the errors specified for -.BR semop (3). -The -.BR bus_poll_timed (3) -function may also set \fIerrno\fP to any of the errors specified for -.BR clock_gettime (3). -.SH SEE ALSO -.BR bus-create (1), -.BR bus (5), -.BR libbus (7), -.BR bus_open (3), -.BR bus_write (3), -.BR bus_read (3), -.BR semop (3), -.BR clock_gettime (3) -.SH AUTHORS -Principal author, Mattias Andrée. See the LICENSE file for the full -list of authors. -.SH LICENSE -MIT/X Consortium License. -.SH BUGS -Please report bugs to https://github.com/maandree/bus/issues or to -maandree@member.fsf.org diff --git a/doc/man/bus_read.3 b/doc/man/bus_read.3 deleted file mode 100644 index 1caadfb..0000000 --- a/doc/man/bus_read.3 +++ /dev/null @@ -1,79 +0,0 @@ -.TH BUS_READ 3 BUS-%VERSION% -.SH NAME -bus_read, bus_read_timed - Listen for new messages a bus -.SH SYNOPSIS -.LP -.nf -#include <bus.h> -.P -int bus_read(const bus_t *\fIbus\fP, int (*\fIcallback\fP)(const char *\fImessage\fP, void *\fIuser_data\fP), - void *\fIuser_data\fP); -int bus_read_timed(const bus_t *\fIbus\fP, int (*\fIcallback\fP)(const char *\fImessage\fP, void *\fIuser_data\fP), - void *\fIuser_data\fP, const struct timespec *\fItimeout\fP, clockid_t \fIclockid\fP); -.fi -.SH DESCRIPTION -The -.BR bus_read () -function waits for new message to be sent on the bus specified in -\fIbus\fP, as provieded by a previous call to the -.BR bus_open () -function. Once a message is received, the \fIcallback\fP function is -invoked. The \fImessage\fP argument to the callback is the received -message, and \fIuser_data\fP for \fIcallback\fP should be -\fIuser_data\fP from -.BR bus_read (). -However, once -.BR bus_read () -has ensured that it will receive any message sent on the bus, it shall -invoke the \fIcallback\fP function with \fImessage\fP set to \fINULL\fP, -to notify the process that it can perform any action that requires that -it is listening on the bus. -.PP -After \fIcallback\fP returns, \fImessage\fP may be override. Therefore -\fIcallback\fP should copy \fImessage\fP and start a new thread that -uses the copy of \fImessage\fP. \fIcallback\fP shall return -1 on -failure, 0 if -.BR bus_read () -should stop listening or 1 if -.BR bus_read () -should continue listening. -.PP -The -.BR bus_read_timed () -function behaves like -.BR bus_read (), -except it will automatically fail and set \fIerrno\fP to \fBEAGAIN\fP -when the specified time has passed. The time is specified as an -absolute time using the parameter \fItimeout\fP. The behaviour is -unspecified if \fItimeout\fP is \fINULL\fP. \fItimeout\fP is measured -with the clock whose ID is specified by the \fIclockid\fP parameter. -This clock must be a predicitable clock. -.SH RETURN VALUES -Upon successful completion, these functions returns 0. Otherwise the -function returns -1 and sets \fIerrno\fP to indicate the error. -.SH ERRORS -The -.BR bus_read (3) -function may fail and set \fIerrno\fP to any of the errors specified for -.BR semop (3). -The -.BR bus_read_timed (3) -function may also set \fIerrno\fP to any of the errors specified for -.BR clock_gettime (3). -.SH SEE ALSO -.BR bus-create (1), -.BR bus (5), -.BR libbus (7), -.BR bus_open (3), -.BR bus_write (3), -.BR bus_poll (3), -.BR semop (3), -.BR clock_gettime (3) -.SH AUTHORS -Principal author, Mattias Andrée. See the LICENSE file for the full -list of authors. -.SH LICENSE -MIT/X Consortium License. -.SH BUGS -Please report bugs to https://github.com/maandree/bus/issues or to -maandree@member.fsf.org diff --git a/doc/man/bus_unlink.3 b/doc/man/bus_unlink.3 deleted file mode 100644 index 83ec760..0000000 --- a/doc/man/bus_unlink.3 +++ /dev/null @@ -1,56 +0,0 @@ -.TH BUS_UNLINK 3 BUS-%VERSION% -.SH NAME -bus_unlink - Remove a bus -.SH SYNOPSIS -.LP -.nf -#include <bus.h> -.P -int bus_unlink(const char *\fIfile\fP); -.fi -.SH DESCRIPTION -The -.BR bus_unlink () -function removes the bus assoicated with the pathname stored in -\fIfile\fP. The function also unlinks the file. -.SH RETURN VALUES -Upon successful completion, the function returns 0. Otherwise the -function returns -1 and sets \fIerrno\fP to indicate the error. -.SH ERRORS -.TP -.B EINVAL -The bus does not exist. -.TP -.B EACCES -Operation permission is denied to the calling process. -.TP -.B EPERM -The user does not have permission to remove the bus. -.PP -The -.BR bus_unlink (3) -function may also fail and set \fIerrno\fP to any of the errors -specified for the routines -.BR unlink (2), -.BR open (2), -.BR semget (3) -and -.BR shmget (3). -.SH SEE ALSO -.BR bus-create (1), -.BR bus (5), -.BR libbus (7), -.BR bus_create (3), -.BR bus_close (3), -.BR unlink (2), -.BR open (2), -.BR semget (3), -.BR shmget (3) -.SH AUTHORS -Principal author, Mattias Andrée. See the LICENSE file for the full -list of authors. -.SH LICENSE -MIT/X Consortium License. -.SH BUGS -Please report bugs to https://github.com/maandree/bus/issues or to -maandree@member.fsf.org diff --git a/doc/man/bus_write.3 b/doc/man/bus_write.3 deleted file mode 100644 index 4513c29..0000000 --- a/doc/man/bus_write.3 +++ /dev/null @@ -1,64 +0,0 @@ -.TH BUS_WRITE 3 BUS-%VERSION% -.SH NAME -bus_write, bus_write_timed - Broadcast a message a bus -.SH SYNOPSIS -.LP -.nf -#include <bus.h> -.P -int bus_write(const bus_t *\fIbus\fP, const char *\fImessage\fP, int \fIflags\fP); -int bus_write_timed(const bus_t *\fIbus\fP, const char *\fImessage\fP, - const struct timespec *\fItimeout\fP, clockid_t \fIclockid\fP); -.fi -.SH DESCRIPTION -The -.BR bus_write () -function broadcasts a message on the bus whose information is stored in -\fIbus\fP. The message read by the function is stored in the parameter -\fImessage\fP. It may not exceeed 2048 bytes, including NULL termination. -.PP -The -.BR bus_write () -function shall fail, and set \fIerrno\fP to \fIEAGAIN\fP, if the call -would suspend the process and (\fIflags\fP &BUS_NOWAIT). -.PP -The -.BR bus_write_timed () -function behaves like -.BR bus_write (), -except if it is not able to write the \fImessage\fP within the specified -time, it will fail and set \fIerrno\fP to \fBEAGAIN\fP. The time is -specified as an absolute time using the parameter \fItimeout\fP. The -behaviour is unspecified if \fItimeout\fP is \fINULL\fP. \fItimeout\fP -is measured with the clock whose ID is specified by the \fIclockid\fP -parameter. This clock must be a predicitable clock. -.SH RETURN VALUES -Upon successful completion, these functions returns 0. Otherwise the -function returns -1 and sets \fIerrno\fP to indicate the error. -.SH ERRORS -The -.BR bus_write (3) -function may fail and set \fIerrno\fP to any of the errors specified for -.BR semop (3). -The -.BR bus_write_timed (3) -function may also set \fIerrno\fP to any of the errors specified for -.BR clock_gettime (3). -.SH SEE ALSO -.BR bus-create (1), -.BR bus (5), -.BR libbus (7), -.BR bus_open (3), -.BR bus_read (3), -.BR bus_poll (3), -.BR bus_chown (3), -.BR bus_chmod (3), -.BR clock_gettime (3) -.SH AUTHORS -Principal author, Mattias Andrée. See the LICENSE file for the full -list of authors. -.SH LICENSE -MIT/X Consortium License. -.SH BUGS -Please report bugs to https://github.com/maandree/bus/issues or to -maandree@member.fsf.org diff --git a/doc/man/libbus.7 b/doc/man/libbus.7 deleted file mode 100644 index 804ee97..0000000 --- a/doc/man/libbus.7 +++ /dev/null @@ -1,39 +0,0 @@ -.TH LIBBUS 7 BUS-%VERSION% -.SH NAME -libbus - A simple daemonless system for broadcasting messages locally -.SH DESCRIPTION -.BR bus -is a stupid-simple, thrilless, daemonless interprocess communication -system for broadcasting messages. -.SH RATIONALE -We need an interprocess communication system similar to message queues. -But we need broadcasting rather than anycasting, so we have a fast, -simple and daemonless system for announcing events to any processes that -might be interested. -.SH FUTURE DIRECTION -None. -.SH SEE ALSO -.BR bus (1), -.BR bus (5), -.BR bus_create (3), -.BR bus_unlink (3), -.BR bus_open (3), -.BR bus_close (3), -.BR bus_write (3), -.BR bus_write_timed (3), -.BR bus_read (3), -.BR bus_read_timed (3), -.BR bus_poll_start (3), -.BR bus_poll_stop (3), -.BR bus_poll (3), -.BR bus_poll_timed (3), -.BR bus_chown (3), -.BR bus_chmod (3) -.SH AUTHORS -Principal author, Mattias Andrée. See the LICENSE file for the full -list of authors. -.SH LICENSE -MIT/X Consortium License. -.SH BUGS -Please report bugs to https://github.com/maandree/bus/issues or to -maandree@member.fsf.org diff --git a/doc/protocol b/doc/protocol index f45799e..116c1b2 100644 --- a/doc/protocol +++ b/doc/protocol @@ -45,4 +45,3 @@ and `V(a)` is done when exiting the scope. It also means that these actions [P(a) and V(a)] are undone when the process exits, or if the call fails. `with V(a)` is to `V(a)` as `with P(a)` is to `P(a)`. - |