start-stop-daemon - start and stop system daemon programs
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.
behaves similar to
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
from starting the daemon. All matching processes will be sent the TERM
signal (or the one specified via --signal or --retry) if
is specified. For daemons which have long-lived children
which need to live through a
you must specify a pidfile.
-S, --start [--] arguments
Check for the existence of a specified process.
If such a process exists,
does nothing, and exits with error status 1 (0 if
If such a process does not exist, it starts an
instance, using either the executable specified by
or, if specified, by
Any arguments given after
on the command line are passed unmodified to the program being
Checks for the existence of a specified process.
If such a process exists,
sends it the signal specified by
and exits with error status 0.
If such a process does not exist,
exits with error status 1
is specified). If
is specified, then
will check that the process(es) have terminated.
Show usage information and exit.
Show the program version and exit.
Check whether a process has created the file
Check for processes that are instances of this executable (according to
Check for processes with the name
Check for processes owned by the user specified by
Change to group or gid when starting the process.
specifies the signal to send to processes being stopped (default TERM).
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.
is specified instead of
then the schedule
is used, where
is the signal specified with
is a list of at least two items separated by slashes
each item may be
which means to send that signal,
which means to wait that many seconds for processes to
which means to repeat the rest of the schedule forever if
If the end of the schedule is reached and
is not specified, then
exits with error status 2.
If a schedule is specified, then any signal specified
start the process specified by
If not specified, defaults to the argument given to
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) taken.
Do not print informational messages; only display error messages.
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
option is not specified. The
option is only for
groups that the user isn't normally a member of (like adding per process
group membership for generic users like
Chdir and chroot to
before starting the process. Please note that the pidfile is also written
after the chroot.
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
Typically used with programs that don't detach on their own. This option
to fork before starting the process, and force it into the background.
cannot check the exit status if the process fails to execute for
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.
This alters the priority of the process before starting it.
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.
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.
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
create the file referenced with
and place the pid into it just before executing the process. Note, the
file will not be removed when stopping the program.
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
Print verbose informational messages.
returns 0 if the requested action was performed, or if
is specified and either
was specified and a matching process was already running, or
was specified and there were no matching processes. If
was not specified and nothing was done, 1 is returned. If
were specified, but the end of the schedule was reached and the processes were
still running, the error value is 2. For all other errors, the status is 3.
Start the food daemon, unless one is already running (a process named
food, running as user food, with pid in food.pid):