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start-stop-daemon(8)                      dpkg utilities                     start-stop-daemon(8)

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 pro‐
       cesses.  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 kil‐
       lall(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 spec‐
       ify 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  inter‐
              preted  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 ker‐
              nel, 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/time‐
              out/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  pri‐
              mary  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 back‐
              ground.  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 pro‐
              grams 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  re‐
              direct  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  start‐
              ing it (since version 1.15.0).  The priority can be optionally specified by append‐
              ing 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 prior‐
              ity 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  --back‐
              ground 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 -- --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 /run/food.pid --retry 5

       Demonstration 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

Debian Project                              2014-03-26                       start-stop-daemon(8)

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