| -S--start | 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. |
| --pidpid | Check for a process with the specified pid (since version 1.17.6). The pid must be a number greater than 0. |
| --ppidppid | 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--pidfilepidfile | 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 pidfile. Warning: Using this match option with a world-writable pidfile or using it alone with a daemon that writes the pidfile as an unprivileged (non-root) user will be refused with an error (since version 1.19.3) as this is a security risk, because either any user can write to it, or if the daemon gets compromised, the contents of the pidfile cannot be trusted, and then a privileged runner (such as an init script executed as root) would end up acting on any system process. Using /dev/null is exempt from these checks. |
| -x--execexecutable | 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--nameprocess-name | 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--userusername|uid | Note: Using this matching option alone will cause all processes matching the user to be acted on. |
| -g--groupgroup|gid | Change to group or gid when starting the process. |
| -s--signalsignal | With --stop, specifies the signal to send to processes being stopped (default TERM). |
| -R--retrytimeout|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 specified, then start-stop-daemon exits with error status 2. If a schedule is specified, then any signal specified with --signal is ignored. |
| -a--startaspathname | 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--chuidusername|uid | 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(1) 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--chrootroot | Change directory and chroot to root before starting the process. Please note that the pidfile is also written after the chroot. |
| -d--chdirpath | Change directory 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 change directory to the root directory before starting the process. |
| -b--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. |
| --notify-await | Wait for the background process to send a readiness notification before considering the service started (since version 1.19.3). This implements parts of the systemd readiness protocol, as specified in the sd_notify(3) manual page. The following variables are supported: |
| READY=1 | The program is ready to give service, so we can exit safely. |
| EXTEND_TIMEOUT_USEC=number | The program requests to extend the timeout by number microseconds. This will reset the current timeout to the specified value. |
| ERRNO=number | The program is exiting with an error. Do the same and print the user-friendly string for the errno value. |
| --notify-timeouttimeout | Set a timeout for the --notify-await option (since version 1.19.3). When the timeout is reached, start-stop-daemon will exit with an error code, and no readiness notification will be awaited. The default is 60 seconds. |
| -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. |
| -O--outputpathname | Redirect stdout and stderr to pathname when forcing the daemon into the background (since version 1.20.6). Only relevant when using --background. |
| -N--nicelevelint | This alters the priority of the process before starting it. |
| -P--procschedpolicy:priority | This option might do nothing on some systems, where POSIX process scheduling is not supported. |
| -I--ioschedclass:priority | This option might do nothing on some systems, where Linux IO scheduling is not supported. |
| -k--umaskmask | This sets the umask of the process before starting it (since version 1.13.22). |
| -m--make-pidfile | 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. |
| --remove-pidfile | Used when stopping a program that does not remove its own pid file (since version 1.17.19). This option will make start-stop-daemon remove the file referenced with --pidfile after terminating the process. |
| -v--verbose | 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 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. |
| 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. |
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
- --pidpid
Check for a process with the specified pid (since version 1.17.6). The pid must be a number greater than 0.
- --ppidppid
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, --pidfilepidfile
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 pidfile.
Warning: Using this match option with a world-writable pidfile or using it alone with a daemon that writes the pidfile as an unprivileged (non-root) user will be refused with an error (since version 1.19.3) as this is a security risk, because either any user can write to it, or if the daemon gets compromised, the contents of the pidfile cannot be trusted, and then a privileged runner (such as an init script executed as root) would end up acting on any system process. Using /dev/null is exempt from these checks.
- -x, --execexecutable
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, --nameprocess-name
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, --userusername|uid
Note: Using this matching option alone will cause all processes matching the user to be acted on.
Generic options
- -g, --groupgroup|gid
Change to group or gid when starting the process.
- -s, --signalsignal
With --stop, specifies the signal to send to processes being stopped (default TERM).
- -R, --retrytimeout|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 specified, then start-stop-daemon exits with error status 2. If a schedule is specified, then any signal specified with --signal is ignored.
- -a, --startaspathname
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, --chuidusername|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(1) 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, --chrootroot
Change directory and chroot to root before starting the process. Please note that the pidfile is also written after the chroot.
- -d, --chdirpath
Change directory 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 change directory to the root directory before starting the process.
- -b, --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.
- --notify-await
Wait for the background process to send a readiness notification before considering the service started (since version 1.19.3). This implements parts of the systemd readiness protocol, as specified in the sd_notify(3) manual page. The following variables are supported:
- READY=1
The program is ready to give service, so we can exit safely.
- EXTEND_TIMEOUT_USEC=number
The program requests to extend the timeout by number microseconds. This will reset the current timeout to the specified value.
- ERRNO=number
The program is exiting with an error. Do the same and print the user-friendly string for the errno value.
- --notify-timeouttimeout
Set a timeout for the --notify-await option (since version 1.19.3). When the timeout is reached, start-stop-daemon will exit with an error code, and no readiness notification will be awaited. The default is 60 seconds.
- -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.
- -O, --outputpathname
Redirect stdout and stderr to pathname when forcing the daemon into the background (since version 1.20.6). Only relevant when using --background.
- -N, --nicelevelint
This alters the priority of the process before starting it.
- -P, --procschedpolicy:priority
This option might do nothing on some systems, where POSIX process scheduling is not supported.
- -I, --ioschedclass:priority
This option might do nothing on some systems, where Linux IO scheduling is not supported.
- -k, --umaskmask
This sets the umask of the process before starting it (since version 1.13.22).
- -m, --make-pidfile
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.
- --remove-pidfile
Used when stopping a program that does not remove its own pid file (since version 1.17.19). This option will make start-stop-daemon remove the file referenced with --pidfile after terminating the process.
- -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 -- --daemonSend 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 5Demonstration 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