Difference between revisions of "Initscripts/Writing rc.d scripts"

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(Example: this is what happens when the init system itself promotes idiotic copy pasting)
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[[Category:Boot process (English)]]
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[[Category:Boot process]]
[[Category:HOWTOs (English)]]
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[[Category:Package development]]
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[[cs:Writing rc.d scripts]]
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[[es:Writing rc.d scripts]]
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[[zh-CN:Writing rc.d scripts]]
 
{{Article summary start}}
 
{{Article summary start}}
{{Article summary text|Writing rc.d (daemon) scripts.}}
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{{Article summary text|Writing rc.d daemon scripts.}}
 
{{Article summary heading|Related}}
 
{{Article summary heading|Related}}
 
{{Article summary wiki|Arch Boot Process}}
 
{{Article summary wiki|Arch Boot Process}}
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{{Article summary end}}
 
{{Article summary end}}
  
As part of Arch's 'BSD-style' init, rc.d scripts are used to control the starting,stopping and restarting of [[Daemon|daemons]]. This guide will help to create your own rc.d scripts.
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{{Warning|Arch only supports [[systemd]]. Arch's old initscripts package is obsolete and is no longer supported. All Arch users need to move to systemd.}}
  
==Guideline==
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[[Initscripts]] uses rc.d scripts to used to control the starting, stopping and restarting of [[Daemon|daemons]].
*Source {{Filename|/etc/rc.conf}}, {{Filename|/etc/rc.d/functions}}, and optionally {{Filename|/etc/conf.d/DAEMON_NAME}}.
+
*Arguments and other daemon options should be placed in {{Filename|/etc/conf.d/DAEMON_NAME}}. This is done to separate configuration from logic and to keep a consistent style among daemon scripts.
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*Use functions in {{Filename|/etc/rc.d/functions}}.
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*Include at least start, stop and restart.
+
  
==Prototype==
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== Guideline ==
<pre>
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* Source {{ic|/etc/rc.conf}}, {{ic|/etc/rc.d/functions}}, and optionally {{ic|/etc/conf.d/DAEMON_NAME}}.
#!/bin/bash
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* Arguments and other daemon options should be placed in {{ic|/etc/conf.d/DAEMON_NAME}}. This is done to separate configuration from logic and to keep a consistent style among daemon scripts.
 +
* Use functions in {{ic|/etc/rc.d/functions}} instead of duplicating their functionality.
 +
* Include at least start, stop and restart as arguments to the script.
  
. /etc/rc.conf
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== Available functions ==
. /etc/rc.d/functions
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* There are some functions provided by {{ic|/etc/rc.d/functions}}:
 +
** {{Ic|stat_busy "''message''"}}: set status ''busy'' for printed message (e.g. <nowiki>Starting daemon  [BUSY]</nowiki>)
 +
** {{Ic|stat_done}}: set status ''done'' (e.g. <nowiki>Starting daemon  [DONE]</nowiki>)
 +
** {{Ic|stat_fail}}: set status ''failed'' (e.g. <nowiki>Starting daemon  [FAILED]</nowiki>)
 +
** {{Ic|get_pid ''program''}}: get PID of the program
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** {{Ic|ck_pidfile ''PID-file'' ''program''}}: check whether PID-file is still valid for the program (e.g. <nowiki>ck_pidfile /var/run/daemon.pid daemon || rm -f /var/run/daemon.pid</nowiki>)
 +
** {{Ic|<nowiki>[add|rm]_daemon</nowiki> ''program''}}: add/remove program to running daemons (stored in {{ic|/run/daemons/}})
  
DAEMON=DAEMON_NAME
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Full list of functions is much longer and most possibilities (like way to control whether or not non-root users can launch daemon) are still undocumented and can be learned only from {{ic|/etc/rc.d/functions}} source. See also {{Ic|man rc.d}}.
ARGS=
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[ -r /etc/conf.d/$DAEMON.conf ] && . /etc/conf.d/$DAEMON.conf
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+
PID=$(pidof -o %PPID $DAEMON)
+
 
+
case "$1" in
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  start)
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    stat_busy "Starting $DAEMON daemon"
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    [ -z "$PID" ] && $DAEMON $ARGS &>/dev/null
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    if [ $? = 0 ]; then
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      add_daemon $DAEMON
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      stat_done
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    else
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      stat_fail
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      exit 1
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    fi
+
    ;;
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  stop)
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    stat_busy "Stopping $DAEMON daemon"
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    [ -n "$PID" ] && kill $PID &>/dev/null
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    if [ $? = 0 ]; then
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      rm_daemon $DAEMON
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      stat_done
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    else
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      stat_fail
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      exit 1
+
    fi
+
    ;;
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  restart)
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    $0 stop
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    sleep 1
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    $0 start
+
    ;;
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  status)
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    stat_busy "Checking $DAEMON status"
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    ck_status $DAEMON
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    ;;
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  *)
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    echo "usage: $0 {start|stop|restart|status}"
+
esac
+
</pre>
+
  
==Example==
+
== Example ==
The following is an example for ''tftpd''. Look in {{Filename|/etc/rc.d}} for a greater variety.
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The following is an example for ''crond''. Look in {{ic|/etc/rc.d}} for greater variety.
  
 
The configuration file:
 
The configuration file:
{{File|name=/etc/conf.d/tftpd|content=<nowiki>ARGS="-l -s /var/tftpboot -c"</nowiki>}}
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{{hc|/etc/conf.d/crond|2=<nowiki>ARGS="-S -l info"</nowiki>}}
  
 
The actual script:
 
The actual script:
{{File|name=/etc/rc.d/tftpd|content=<nowiki>
+
{{hc|/etc/rc.d/crond|2=<nowiki>
 
#!/bin/bash
 
#!/bin/bash
  
Line 81: Line 46:
 
. /etc/rc.d/functions
 
. /etc/rc.d/functions
  
DAEMON=tftpd
+
DAEMON=crond
 
ARGS=
 
ARGS=
  
 
[ -r /etc/conf.d/$DAEMON ] && . /etc/conf.d/$DAEMON
 
[ -r /etc/conf.d/$DAEMON ] && . /etc/conf.d/$DAEMON
  
PID=$(pidof -o %PPID in.tftpd)
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PID=$(get_pid $DAEMON)
  
 
case "$1" in
 
case "$1" in
 
  start)
 
  start)
 
   stat_busy "Starting $DAEMON"
 
   stat_busy "Starting $DAEMON"
   [ -z "$PID" ] && in.tftpd $ARGS &>/dev/null
+
   [ -z "$PID" ] && $DAEMON $ARGS &>/dev/null
 
   if [ $? = 0 ]; then
 
   if [ $? = 0 ]; then
 
     add_daemon $DAEMON
 
     add_daemon $DAEMON

Revision as of 00:42, 18 June 2013

Summary help replacing me
Writing rc.d daemon scripts.
Related
Arch Boot Process
Daemon
rc.conf
Warning: Arch only supports systemd. Arch's old initscripts package is obsolete and is no longer supported. All Arch users need to move to systemd.

Initscripts uses rc.d scripts to used to control the starting, stopping and restarting of daemons.

Guideline

  • Source /etc/rc.conf, /etc/rc.d/functions, and optionally /etc/conf.d/DAEMON_NAME.
  • Arguments and other daemon options should be placed in /etc/conf.d/DAEMON_NAME. This is done to separate configuration from logic and to keep a consistent style among daemon scripts.
  • Use functions in /etc/rc.d/functions instead of duplicating their functionality.
  • Include at least start, stop and restart as arguments to the script.

Available functions

  • There are some functions provided by /etc/rc.d/functions:
    • stat_busy "message": set status busy for printed message (e.g. Starting daemon [BUSY])
    • stat_done: set status done (e.g. Starting daemon [DONE])
    • stat_fail: set status failed (e.g. Starting daemon [FAILED])
    • get_pid program: get PID of the program
    • ck_pidfile PID-file program: check whether PID-file is still valid for the program (e.g. ck_pidfile /var/run/daemon.pid daemon || rm -f /var/run/daemon.pid)
    • [add|rm]_daemon program: add/remove program to running daemons (stored in /run/daemons/)

Full list of functions is much longer and most possibilities (like way to control whether or not non-root users can launch daemon) are still undocumented and can be learned only from /etc/rc.d/functions source. See also man rc.d.

Example

The following is an example for crond. Look in /etc/rc.d for greater variety.

The configuration file:

/etc/conf.d/crond
ARGS="-S -l info"

The actual script:

/etc/rc.d/crond
#!/bin/bash

. /etc/rc.conf
. /etc/rc.d/functions

DAEMON=crond
ARGS=

[ -r /etc/conf.d/$DAEMON ] && . /etc/conf.d/$DAEMON

PID=$(get_pid $DAEMON)

case "$1" in
 start)
   stat_busy "Starting $DAEMON"
   [ -z "$PID" ] && $DAEMON $ARGS &>/dev/null
   if [ $? = 0 ]; then
     add_daemon $DAEMON
     stat_done
   else
     stat_fail
     exit 1
   fi
   ;;
 stop)
   stat_busy "Stopping $DAEMON"
   [ -n "$PID" ] && kill $PID &>/dev/null
   if [ $? = 0 ]; then
     rm_daemon $DAEMON
     stat_done
   else
     stat_fail
     exit 1
   fi
   ;;
 restart)
   $0 stop
   sleep 1
   $0 start
   ;;
 *)
   echo "usage: $0 {start|stop|restart}"  
esac