openrc/man/start-stop-daemon.8

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.Dd Dec 15, 2007
.Dt START-STOP-DAEMON 8 SMM
.Os OpenRC
.Sh NAME
.Nm start-stop-daemon
.Nd ensures that daemons start and stop
.Sh SYNOPSIS
.Nm
.Fl S , -start
.Ar daemon
.Op Fl -
.Op Ar arguments
.Nm
.Fl K , -stop
.Ar daemon
.Nm
.Fl s , -signal
.Ar signal
.Ar daemon
.Sh DESCRIPTION
.Nm
provides a consistent method of starting, stopping and signalling daemons.
If a daemon cannot background by itself, nor create a pidfile,
.Nm
can do it for the daemon in a secure fashion.
.Nm
also ensures that a daemon really has started by checking to see if it still
exists for a short time after it has started. This is because some badly
written daemons like to daemonize before checking their configuration, doing
sanity checks, etc. Likewise,
.Nm
ensures that a daemon really stops as well, again by using the information
above to ensure that it's not running.
.Pp
If
.Nm
is used in an OpenRC service, then OpenRC can in turn check to see if the
daemon is still running. If not, then the service is marked as crashed.
.Pp
Here are the options to specify the daemon and how it should start or stop:
.Bl -tag -width indent 
.It Fl x , -exec Ar daemon
The daemon we start or stop.
.It Fl p , -pidfile Ar pidfile
When starting, we expect the daemon to create a valid pidfile within a
reasonable amount of time. When stopping we only stop the pid(s) listed in
the pidfile.
.It Fl n , -name Ar name
For whatever reason, some daemons don't create pidfiles or change their
process name. You can specify name here to be the process name to stop.
You may need to use this for interpreted daemons using languages such as
perl, ruby, shell, etc.
.It Fl u , -user Ar user Ns Op : Ns Ar group
Start the daemon as the user and update $HOME accordingly or stop daemons
owned by the user. You can optionally append a groupname here also.
.It Fl t , -test
Print the action(s) that would be taken, but don't actually do anything.
The return value is set as if the command was taken and worked.
.El
.Pp
These options are only used for starting daemons:
.Bl -tag -width indent
.It Fl b , -background
Force the daemon into the background. Some daemons don't create pidfiles, so a
good trick is to get the daemon to run in the foreground, and use the this
option along with
.Fl m , -make-pidfile
to create a working pidfile.
.It Fl d , -chdir Ar path
chdir to this directory before starting the daemon.
.It Fl r , -chroot Ar path
chroot to this directory before starting the daemon. All other paths, such
as the path to the daemon, chdir and pidfile, should be relative to the chroot.
.It Fl e , -env Ar VAR=VALUE
Set the environment variable VAR to VALUE.
.It Fl g , -group Ar group
Start the daemon as in the group.
.It Fl m , -make-pidfile
Saves the pid of the daemon in the file specified by the
.Fl p , -pidfile
option. Only useful when used with daemons that run in the foreground and
forced into the background with the
.Fl -b , -background
option.
.It Fl n , -nice Ar level
Modifies the scheduling priority of the daemon.
.It Fl 1 , -stdout Ar logfile
Redirect the standard output of the process to logfile when started with
.Fl background .
Must be an absolute pathname, but relative to the path optionally given with
.Fl r , -chroot .
The logfile can also be a named pipe.
.It Fl 2 , -stderr Ar logfile
The same thing as
.Fl 1 , -stdout
but with the standard error output.
.El
.Pp
These options are only used for stopping daemons:
.Bl -tag -width indent
.It Fl R , -retry Ar timeout | Ar signal Ns / Ns Ar timeout
You can either specify a timeout or a multiple signal/timeout pairs as a
stopping schedule.
If not specified then a default value of SIGTERM/5 is
assumed.
.El
.Sh SEE ALSO
.Xr chdir 2 ,
.Xr chroot 2 ,
.Xr nice 2
.Sh AUTHORS
.An "Roy Marples" Aq roy@marples.name