path: root/utils/start-stop-daemon.8

.TH START\-STOP\-DAEMON 8 "15th March 1997" "Debian Project" "dpkg utilities"
.SH NAME
start\-stop\-daemon \- start and stop system daemon programs
.SH SYNOPSIS
.B start-stop-daemon
.BR -S | --start
.IR options
.RB [ \-\- ]
.IR arguments
.HP
.B start-stop-daemon
.BR -K | --stop
.IR options
.HP
.B start-stop-daemon
.BR -H | --help
.HP
.B start-stop-daemon
.BR -V | --version
.SH DESCRIPTION
.B start\-stop\-daemon
is used to control the creation and termination of system-level processes.
Using the
.BR --exec ", " --pidfile ", " --user ", and " --name " options,"
.B start\-stop\-daemon
can be configured to find existing instances of a running process.

With
.BR --start ,
.B start\-stop\-daemon
checks for the existence of a specified process.
If such a process exists,
.B start\-stop\-daemon
does nothing, and exits with error status 1 (0 if
.BR --oknodo
is specified).  
If such a process does not exist, it starts an
instance, using either the executable specified by
.BR --exec ,
(or, if specified, by
.BR --startas ).
Any arguments given after
.BR --
on the command line are passed unmodified to the program being
started.  If
.B --retry
is specified then 
.B start-stop-daemon
will check that the process(es) have terminated.

With 
.BR --stop ,
.B start\-stop\-daemon
also checks for the existence of a specified process.
If such a process exists,
.B start\-stop\-daemon
sends it the signal specified by
.BR --signal ,
and exits with error status 0.
If such a process does not exist,
.B start\-stop\-daemon
exits with error status 1
(0 if
.BR --oknodo
is specified).

.SH OPTIONS

.TP
\fB-x\fP|\fB--exec\fP \fIexecutable\fP
Check for processes that are instances of this executable (according to 
.B /proc/\fIpid\fB/exe\fP
).
.TP
\fB-p\fP|\fB--pidfile\fP \fIpid-file\fP
Check for processes whose process-id is specified in 
.IR pid-file .
.TP
\fB-u\fP|\fB--user\fP \fIusername\fP|\fIuid\fP
Check for processes owned by the user specified by
.I username 
or
.IR uid .
.TP
\fB-n\fP|\fB--name\fP \fIprocess-name\fP
Check for processes with the name
.I process-name
(according to
.BR /proc/\fIpid\fB/stat\fP ).
.TP
\fB-s\fP|\fB--signal\fP \fIsignal\fP
With
.BR --stop ,
specifies the signal to send to processes being stopped (default 15).
.TP
\fB-R\fP|\fB--retry\fP \fItimeout\fP|\fIschedule\fP
With
.BR --stop ,
specifies that
.B 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
.I timeout
is specified instead of
.I schedule
then the schedule
.IB signal / timeout /KILL/ timeout
is used, where
.I signal
is the signal specified with
.BR --signal .

.I schedule
is a list of at least two items separated by slashes
.RB ( / );
each item may be
.BI - signal-number
or [\fB\-\fP]\fIsignal-name\fP,
which means to send that signal,
or
.IR timeout ,
which means to wait that many seconds for processes to
exit,
or
.BR forever ,
which means to repeat the rest of the schedule forever if
necessary.

If the end of the schedule is reached and
.BR forever
is not specified, then
.B start-stop-daemon
exits with error status 2.
If a schedule is specified, then any signal specified
with
.B --signal
is ignored.
.TP
\fB-a\fP|\fB--startas\fP \fIpathname\fP
With 
.BR --start ,
start the process specified by 
.IR pathname .
If not specified, defaults to the argument given to
.BR --exec .
.TP
.BR -t | --test
Print actions that would be taken and set appropriate return value,
but take no action.
.TP
.BR -o | --oknodo
Return exit status 0 instead of 1 if no actions are (would be) taken.
.TP
.BR -q | --quiet
Do not print informational messages; only display error messages.
.TP
\fB-c\fP|\fB--chuid\fP \fIusername\fR|\fIuid\fP
Change to this username/uid before starting the process. You can also
specify a group by appending a
.BR : ,
then the group or gid in the same way
as you would for the `chown' command (\fIuser\fP\fB:\fP\fIgroup\fP).
When using this option
you must realize that the primary and supplemental groups are set as well,
even if the
.B --group
option is not specified.  The
.B --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
.BR nobody ).
.TP
\fB-r\fP|\fB--chroot\fP \fIroot\fP
Chdir and chroot to
.I root
before starting the process. Please note that the pidfile is also written
after the chroot.
.TP
.BR -b | --background
Typically used with programs that don't detach on their own. This option
will force
.B start-stop-daemon
to fork before starting the process, and force it into the background.
.B WARNING: start-stop-daemon
cannot check the exit status if the process fails to execute for
.B 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 it to do this itself.
.TP
.BR -N | --nicelevel
This alters the prority of the process before starting it.
.TP
.BR -m | --make-pidfile
Used when starting a program that does not create its own pid file. This
option will make
.B start-stop-daemon
create the file referenced with
.B --pidfile
and place the pid into it just before executing the process. Note, it will
not be removed when stopping the program.
.B 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
.B --background
option.
.TP
.BR -v | --verbose
Print verbose informational messages.
.TP
.BR -H | --help
Print help information; then exit.
.TP
.BR -V | --version
Print version information; then exit.

.SH AUTHORS
Marek Michalkiewicz <marekm@i17linuxb.ists.pwr.wroc.pl> based on
a previous version by Ian Jackson <ian@chiark.greenend.org.uk>.

Manual page by Klee Dienes <klee@mit.edu>, partially reformatted
by Ian Jackson.