man > INIT-D-SCRIPT

INIT-D-SCRIPT(5)                         File Formats Manual                        INIT-D-SCRIPT(5)

NAME
       init-d-script — interpreter for short and simple init.d scripts

DESCRIPTION
       Generic init.d script framework to reduce the redundant code in /etc/init.d/.  The goal is to
       create  an  init.d script that is Debian and LSB compliant.  When the Debian policy conflicts
       with the LSB, the Debian policy takes precedence.

       This is a simple example on how init-d-script can be used to start and stop a daemon with PID
       file support:

             #!/bin/sh /lib/init/init-d-script
             ### BEGIN INIT INFO
             # Provides:          atd
             # Required-Start:    $syslog $time $remote_fs
             # Required-Stop:     $syslog $time $remote_fs
             # Default-Start:     2 3 4 5
             # Default-Stop:      0 1 6
             # Short-Description: run at jobs
             # Description:       Debian init script to start the daemon
             #                    running at jobs.
             ### END INIT INFO
             DAEMON=/usr/sbin/atd

       The following variables affect behaviour of an init script:

       DAEMON         Path to daemon being started.  If the init script is not supposed to start any
                      kind  of  daemon,  it  should   be   set   to   “none”   and   the   functions
                      do_start_override(), do_stop_override() and do_status_override() should be de‐
                      fined instead.

       DAEMON_ARGS    Additional arguments, passed to daemon during start.

       DESC           Full  name  or  short description of the daemon, printed on screen.  If unset,
                      this variable defaults to the “NAME” value.

       NAME           Additional environment variables are sourced  from  /etc/default/${NAME}.   If
                      unset, this variable defaults to the basename of the “DAEMON” value.

       COMMAND_NAME   If  this  variable  is  set,  it  is  used as argument to the --name option of
                      start-stop-daemon(8).  It may be useful if the value of the “NAME” variable is
                      longer than the command name length supported by the running kernel.   If  the
                      value  is  verbatim  “none”,  the  command  name will not be used to match the
                      processes.  If unset, this variable defaults to the “NAME” value.

       PIDFILE        Path to file where the process identifier of the started daemon will be stored
                      during start.  If the value is verbatim “none”, the  process  identifier  will
                      not  be  stored  in any file.  If this variable is not set, it gets a sensible
                      default value, so it is rarely necessary to set this variable explicitly.

       RELOAD_SIGNAL  Signal number or name (without the SIG  prefix)  that  will  be  sent  to  the
                      process  on  reload.   If  the  daemon performs reload action upon receiving a
                      SIGHUP signal, this variable should be set to “1” or “HUP”.

       The variables RELOAD_ARGS, START_ARGS and  STOP_ARGS  are  additional  arguments,  passed  to
       start-stop-daemon(8) during reload, start and stop actions, to override the default options.

       Additionally,  it  is possible to change the behaviour of the resulting shell script by over‐
       riding some of the internal functions.  To do so, define function with an  _override  suffix.
       So,   for   example,   to   override   the   do_status()   function,   one  should  define  a
       do_status_override() function.  The exception to this rule is the do_reload() function, whose
       override should be defined as-is, without the above-mentioned suffix.

       Here is a control flow chart that explains what functions are called and when:

             /etc/init.d/script start
               do_start
                 do_start_prepare # no-op
                 do_start_cmd     # start-stop-daemon is called here
                 do_start_cleanup # no-op

             /etc/init.d/script stop
               do_stop
                 do_stop_prepare # no-op
                 do_stop_cmd     # start-stop-daemon is called here
                 do_stop_cleanup # no-op

             /etc/init.d/script status
               do_status

             /etc/init.d/script reload
               do_reload
                 do_usage
                 exit 3

             /etc/init.d/script force-reload
               do_force_reload
                 do_reload   # if overridden
                 do_restart
                   do_restart_prepare
                   do_stop_cmd
                   do_start_cmd
                   do_restart_cleanup

             /etc/init.d/script restart
               do_force_restart
             /etc/init.d/script try-restart
               if do_status; then
                 do_restart
                   do_restart_prepare
                   do_stop_cmd  # start-stop-daemon is called here
                   do_start_cmd # start-stop-daemon is called here
                   do_restart_cleanup

             /etc/init.d/script <arg>
               do_unknown <arg>
                 exit 3

             /etc/init.d/script
               do_usage

       As can be seen, by default, the script does not support the reload action; it should  be  im‐
       plemented by the script writer by defining a do_reload() function.

       If  do_reload()  is  not defined but do_reload_cmd() is, the latter will be called on reload,
       after do_reload_prepare() and before do_reload_cleanup().

SEE ALSO
       inittab(8), service(8), update-rc.d(8).

AUTHORS
       Petter Reinholdtsen <pere AT debian.org>

Debian                                     August 5, 2019                           INIT-D-SCRIPT(5)