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diff --git a/doc/sysvinitfiles b/doc/sysvinitfiles new file mode 100644 index 00000000..fcc90b5e --- /dev/null +++ b/doc/sysvinitfiles @@ -0,0 +1,212 @@ +Writing System V init scripts for Red Hat Linux +=============================================== + +All System V init scripts are named /etc/rc.d/init.d/<servicename> +where <servicename> is the name of the service. There must be no +".init" suffix. + +This path will very likely be moved to /etc/init.d in the future. +Once Red Hat Linux 7.0 is installed, you can access scripts as +/etc/init.d/<servicename>, via symlinks. + +Sample Script +============= + +#!/bin/bash +# +# /etc/rc.d/init.d/<servicename> +# +# <description of the *service*> +# <any general comments about this init script> +# +# <tags -- see below for tag definitions. *Every line* from the top +# of the file to the end of the tags section must begin with a # +# character. After the tags section, there should be a blank line. +# This keeps normal comments in the rest of the file from being +# mistaken for tags, should they happen to fit the pattern.> + +# Source function library. +. /etc/init.d/functions + +<define any local shell functions used by the code that follows> + +start() { + echo -n "Starting <servicename>: " + <start daemons, perhaps with the daemon function> + touch /var/lock/subsys/<servicename> + return <return code of starting daemon> +} + +stop() { + echo -n "Shutting down <servicename>: " + <stop daemons, perhaps with the killproc function> + rm -f /var/lock/subsys/<servicename> + return <return code of stopping daemon> +} + +case "$1" in + start) + start + ;; + stop) + stop + ;; + status) + <report the status of the daemons in free-form format, + perhaps with the status function> + ;; + restart) + stop + start + ;; + reload) + <cause the service configuration to be reread, either with + kill -HUP or by restarting the daemons, in a manner similar + to restart above> + ;; + condrestart) + <Restarts the servce if it is already running. For example:> + [ -f /var/lock/subsys/<service> ] && restart || : + probe) + <optional. If it exists, then it should determine whether + or not the service needs to be restarted or reloaded (or + whatever) in order to activate any changes in the configuration + scripts. It should print out a list of commands to give to + $0; see the description under the probe tag below.> + ;; + *) + echo "Usage: <servicename> {start|stop|status|reload|restart[|probe]" + exit 1 + ;; +esac +exit $? + +Notes: + +- The restart and reload functions may be (and commonly are) + combined into one test, vis: + restart|reload) +- You are not prohibited from adding other commands; list all commands + which you intend to be used interactively to the usage message. +- Notice the change in that stop() and start() are now shell functions. + This means that restart can be implemented as + stop + start + instead of + $0 stop + $0 start + This saves a few shell invocations. + +Functions in /etc/init.d/functions +======================================= + +daemon [ --check <name> ] [ --user <username>] + [+/-nicelevel] program [arguments] [&] + + Starts a daemon, if it is not already running. Does + other useful things like keeping the daemon from dumping + core if it terminates unexpectedly. + + --check <name>: + Check that <name> is running, as opposed to simply the + first argument passed to daemon(). + --user <username>: + Run command as user <username> + +killproc program [signal] + + Sends a signal to the program; by default it sends a SIGTERM, + and if the process doesn't die, it sends a SIGKILL a few + seconds later. + + It also tries to remove the pidfile, if it finds one. + +pidofproc program + + Tries to find the pid of a program; checking likely pidfiles, + and using the pidof program. Used mainly from within other + functions in this file, but also available to scripts. + +status program + + Prints status information. Assumes that the program name is + the same as the servicename. + + +Tags +==== + +# chkconfig: <startlevellist> <startpriority> <endpriority> + + Required. <startlevellist> is a list of levels in which + the service should be started by default. <startpriority> + and <endpriority> are priority numbers. For example: + # chkconfig: 2345 20 80 + Read 'man chkconfig' for more information. + + Unless there is a VERY GOOD, EXPLICIT reason to the + contrary, the <endpriority> should be equal to + 100 - <startpriority> + +# description: <multi-line description of service> + + Required. Several lines of description, continued with '\' + characters. The initial comment and following whitespace + on the following lines is ignored. + +# description[ln]: <multi-line description of service in the language \ +# ln, whatever that is> + + Optional. Should be the description translated into the + specified language. + +# processname: + + Optional, multiple entries allowed. For each process name + started by the script, there should be a processname entry. + For example, the samba service starts two daemons: + # processname: smdb + # processname: nmdb + +# config: + + Optional, multiple entries allowed. For each static config + file used by the daemon, use a single entry. For example: + # config: /etc/httpd/conf/httpd.conf + # config: /etc/httpd/conf/srm.conf + + Optionally, if the server will automatically reload the config + file if it is changed, you can append the word "autoreload" to + the line: + # config: /etc/foobar.conf autoreload + +# pidfile: + + Optional, multiple entries allowed. Use just like the config + entry, except that it points at pidfiles. It is assumed that + the pidfiles are only updated at process creation time, and + not later. The first line of this file should be the ASCII + representation of the PID; a terminating newline is optional. + Any lines other than the first line are not examined. + +# probe: true + + Optional, used IN PLACE of processname, config, and pidfile. + If it exists, then a proper reload-if-necessary cycle may be + achieved by running these commands: + + command=$(/etc/rc.d/init.d/SCRIPT probe) + [ -n "$command" ] && /etc/rc.d/init.d/SCRIPT $command + + where SCRIPT is the name of the service's sysv init script. + + Scripts that need to do complex processing could, as an + example, return "run /var/tmp/<servicename.probe.$$" + and implement a "run" command which would execute the + named script and then remove it. + + Note that the probe command should simply "exit 0" if nothing + needs to be done to bring the service into sync with its + configuration files. + +Copyright (c) 2000 Red Hat Software, Inc. |