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start-stop-daemon(8)		  dpkg suite		  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  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

1.19.7				  2019-06-03		  start-stop-daemon(8)

NAME | SYNOPSIS | DESCRIPTION | COMMANDS | OPTIONS | EXIT STATUS | EXAMPLE

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