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 --pid or --pidfile are 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, parent pid, 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 status 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 --oknodo 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 (since version 1.16.1).
-H, --help
Show usage information and exit.
-V, --version
Show the program version and exit.
OPTIONS
Matching options
--pid pid
Check for a process with the specified pid (since version 1.17.6). The pid must be a number greater than 0.
--ppid ppid
Check for a process with the specified parent pid ppid (since version 1.17.7). The ppid must be a number greater than 0.
-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.
Generic 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).
-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 (since version 1.16.5). Used for debugging purposes to see the process output, 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 (since version 1.15.0). 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 (since version 1.15.0). 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 (since version 1.13.22).
-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 referenced with --pidfile and place
the pid into it just before executing the process. Note, the file will only be removed when stopping the program if --remove-pidfile is used. 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.