start-stop-daemon(8)						  dpkg utilities					      start-stop-daemon(8)

NAME

       start-stop-daemon - start and stop system daemon programs

SYNOPSIS

       start-stop-daemon [option...] command

DESCRIPTION

       start-stop-daemon  is  used  to	control  the  creation	and  termination  of  system-level  processes.	Using one of the matching options,
       start-stop-daemon can be configured to find existing instances of a running process.

       Note: unless --pidfile is specified, start-stop-daemon behaves similar to killall(1).  start-stop-daemon will scan the process table  look-
       ing for any processes which match the process name, uid, and/or gid (if specified). Any matching process will prevent --start from starting
       the daemon. All matching processes will be sent the TERM signal (or the one specified via --signal or --retry) if --stop is specified.  For
       daemons which have long-lived children which need to live through a --stop, you must specify a pidfile.

COMMANDS

       -S, --start [--] arguments
	      Check for the existence of a specified process.  If such a process exists, start-stop-daemon does nothing, and exits with error sta-
	      tus 1 (0 if --oknodo is specified).  If such a process does not exist, it starts an instance, using either the executable  specified
	      by  --exec  or,  if  specified, by --startas.  Any arguments given after -- on the command line are passed unmodified to the program
	      being started.

       -K, --stop
	      Checks for the existence of a specified process.	If such a process exists, start-stop-daemon  sends  it	the  signal  specified	by
	      --signal, and exits with error status 0.	If such a process does not exist, start-stop-daemon exits with error status 1 (0 if --okn-
	      odo is specified). If --retry is specified, then start-stop-daemon will check that the process(es) have terminated.

       -T, --status
	      Check for the existence of a specified process, and returns an exit status code, according to the LSB Init Script Actions.

       -H, --help
	      Show usage information and exit.

       -V, --version
	      Show the program version and exit.

MATCHING OPTIONS

       -p, --pidfile pid-file
	      Check whether a process has created the file pid-file. Note: using this matching option alone might cause unintended processes to be
	      acted on, if the old process terminated without being able to remove the pid-file.

       -x, --exec executable
	      Check  for processes that are instances of this executable. The executable argument should be an absolute pathname. Note: this might
	      not work as intended with interpreted scripts, as the executable will point to the interpreter. Take into account processes  running
	      from inside a chroot will also be matched, so other match restrictions might be needed.

       -n, --name process-name
	      Check  for processes with the name process-name. The process-name is usually the process filename, but it could have been changed by
	      the process itself. Note: on most systems this information is retrieved from the process comm name from the kernel, which  tends	to
	      have a relatively short length limit (assuming more than 15 characters is non-portable).

       -u, --user username|uid
	      Check  for processes owned by the user specified by username or uid. Note: using this matching option alone will cause all processes
	      matching the user to be acted on.

OPTIONS

       -g, --group group|gid
	      Change to group or gid when starting the process.

       -s, --signal signal
	      With --stop, specifies the signal to send to processes being stopped (default TERM).

       -R, --retry timeout|schedule
	      With --stop, specifies that start-stop-daemon is to check whether the process(es) do finish. It will check  repeatedly  whether  any
	      matching	processes  are running, until none are. If the processes do not exit it will then take further action as determined by the
	      schedule.

	      If timeout is specified instead of schedule, then the schedule signal/timeout/KILL/timeout is used, where signal is the signal spec-
	      ified with --signal.

	      schedule is a list of at least two items separated by slashes (/); each item may be -signal-number or [-]signal-name, which means to
	      send that signal, or timeout, which means to wait that many seconds for processes to exit, or forever, which  means  to  repeat  the
	      rest of the schedule forever if necessary.

	      If the end of the schedule is reached and forever is not specified, then start-stop-daemon exits with error status 2.  If a schedule
	      is specified, then any signal specified with --signal is ignored.

       -a, --startas pathname
	      With --start, start the process specified by pathname.  If not specified, defaults to the argument given to --exec.

       -t, --test
	      Print actions that would be taken and set appropriate return value, but take no action.

       -o, --oknodo
	      Return exit status 0 instead of 1 if no actions are (would be) taken.

       -q, --quiet
	      Do not print informational messages; only display error messages.

       -c, --chuid username|uid[:group|gid]
	      Change to this username/uid before starting the process. You can also specify a group by appending a :, then the group or gid in the
	      same  way  as you would for the `chown' command (user:group).  If a user is specified without a group, the primary GID for that user
	      is used.	When using this option you must realize that the primary and supplemental groups are set as  well,  even  if  the  --group
	      option  is  not  specified.  The --group option is only for groups that the user isn't normally a member of (like adding per process
	      group membership for generic users like nobody).

       -r, --chroot root
	      Chdir and chroot to root before starting the process. Please note that the pidfile is also written after the chroot.

       -d, --chdir path
	      Chdir to path before starting the process. This is done after the chroot if the -r|--chroot  option  is  set.  When  not	specified,
	      start-stop-daemon will chdir to the root directory before starting the process.

       -b, --background
	      Typically  used  with  programs that don't detach on their own. This option will force start-stop-daemon to fork before starting the
	      process, and force it into the background.  WARNING: start-stop-daemon cannot check the exit status if the process fails to  execute
	      for  any reason. This is a last resort, and is only meant for programs that either make no sense forking on their own, or where it's
	      not feasible to add the code for them to do this themselves.

       -C, --no-close
	      Do not close any file descriptor when forcing the daemon into the background.  Used for debugging purposes to see the  process  out-
	      put, or to redirect file descriptors to log the process output.  Only relevant when using --background.

       -N, --nicelevel int
	      This alters the priority of the process before starting it.

       -P, --procsched policy:priority
	      This alters the process scheduler policy and priority of the process before starting it. The priority can be optionally specified by
	      appending a : followed by the value. The default priority is 0. The currently supported policy values are other, fifo and rr.

       -I, --iosched class:priority
	      This alters the IO scheduler class and priority of the process before starting it. The  priority	can  be  optionally  specified	by
	      appending  a : followed by the value. The default priority is 4, unless class is idle, then priority will always be 7. The currently
	      supported values for class are idle, best-effort and real-time.

       -k, --umask mask
	      This sets the umask of the process before starting it.

       -m, --make-pidfile
	      Used when starting a program that does not create its own pid file. This option will make start-stop-daemon create the  file  refer-
	      enced  with  --pidfile and place the pid into it just before executing the process. Note, the file will not be removed when stopping
	      the program.  NOTE: This feature may not work in all cases. Most notably when  the  program  being  executed  forks  from  its  main
	      process. Because of this, it is usually only useful when combined with the --background option.

       -v, --verbose
	      Print verbose informational messages.

EXIT STATUS

       0      The requested action was performed. If --oknodo was specified, it's also possible that nothing had to be done.  This can happen when
	      --start was specified and a matching process was already running, or when --stop was specified and there were no matching processes.

       1      If --oknodo was not specified and nothing was done.

       2      If --stop and --retry were specified, but the end of the schedule was reached and the processes were still running.

       3      Any other error.

       When using the --status command, the following status codes are returned:

       0      Program is running.

       1      Program is not running and the pid file exists.

       3      Program is not running.

       4      Unable to determine program status.

EXAMPLE

       Start the food daemon, unless one is already running (a process named food, running as user food, with pid in food.pid):

	      start-stop-daemon --start --oknodo --user food --name food 
		   --pidfile /run/food.pid --startas /usr/sbin/food 
		   --chuid food -- --daemon

       Send SIGTERM to food and wait up to 5 seconds for it to stop:

	      start-stop-daemon --stop --oknodo --user food --name food 
		   --pidfile /run/food.pid --retry 5

       Demonstration of a custom schedule for stopping food:

	      start-stop-daemon --stop --oknodo --user food --name food 
		   --pidfile /run/food.pid --retry=TERM/30/KILL/5

Debian Project							    2012-06-17						      start-stop-daemon(8)