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.
-x, --exec executable
Check for processes that are instances of this executable
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)
Do not print informational messages; only display error mes-
-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).
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.
-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
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.
Print verbose informational messages.
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
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.
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 /var/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 /var/run/food.pid --retry 5
Demonstration of a custom schedule for stopping food:
start-stop-daemon --stop --oknodo --user food --name food --pidfile /var/run/food.pid --retry=TERM/30/KILL/5
Marek Michalkiewicz <email@example.com> based on a pre-
vious version by Ian Jackson <firstname.lastname@example.org>.
Manual page by Klee Dienes <email@example.com>, partially reformatted by Ian
Debian Project 2011-07-04 start-stop-daemon(8)
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