start-stop-daemon [option...] command
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
Note: unless --pidfile is specified, start-stop-daemon behaves similar
to killall(1). start-stop-daemon will scan the process table looking
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.
-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 status 1 (0 if --oknodo is specified). If such a process
does not exist, it starts an instance, using either the exe-
cutable specified by --exec or, if specified, by --startas. Any
arguments given after -- on the command line are passed unmodi-
fied to the program being started.
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 --oknodo is specified). If --retry is specified, then
start-stop-daemon will check that the process(es) have termi-
Check for the existence of a specified process, and returns an
exit status code, according to the LSB Init Script Actions.
Show usage information and exit.
Show the program version and exit.
-p, --pidfile pid-file
Check whether a process has created the file pid-file. Note:
using this matching option alone might cause unintended pro-
cesses to be acted on, if the old process terminated without
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 pro-
cesses matching the user to be acted on.
-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
specified 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 speci-
fied, then start-stop-daemon exits with error status 2. If a
schedule is specified, then any signal specified with --signal
-a, --startas pathname
With --start, start the process specified by pathname. If not
specified, defaults to the argument given to --exec.
Print actions that would be taken and set appropriate return
value, but take no action.
Return exit status 0 instead of 1 if no actions are (would be)
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 start-
ing the process.
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.
Do not close any file descriptor when forcing the daemon into
the background. Used for debugging purposes to see the process
output, or to redirect file descriptors to log the process out-
put. 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 spec-
ified by appending a : followed by the value. The default prior-
ity is 0. The currently supported policy values are other, fifo
-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 cur-
rently supported values for class are idle, best-effort and
-k, --umask mask
This sets the umask of the process before starting it.
Used when starting a program that does not create its own pid
file. This option will make start-stop-daemon create the file
referenced with --pidfile and place the pid into it just before
executing the process. Note, the file will not be removed when
running, or when --stop was specified and there were no matching
1 If --oknodo was not specified and nothing was done.
2 If --stop and --retry were specified, but the end of the sched-
ule was reached and the processes were still running.
3 Any other error.
When using the --status command, the following status codes are
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.
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)
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