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
                    defined 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
     overriding 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
     implemented 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@debian.org>