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.
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
, --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).
-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
specified, then start-stop-daemon
exits with error status
2. If a schedule is specified, then any signal specified
with --signal
is ignored.
-a
, --startas
pathname
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
, --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(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
, --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 starting the process.
-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.
--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 procotol, as specified in the sd_notify(3) man
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-timeout
timeout
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
.
-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.
--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.