Provided by: dpkg_1.19.7ubuntu2_amd64 bug

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.

              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  protocol,  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-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.

       -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.

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