xref: /freebsd/usr.sbin/daemon/daemon.8 (revision b6193c2409d847dd32a04f01786eb03e6658ba79)

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.\" $FreeBSD$
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.Dd February 19, 2012
.Dt DAEMON 8
.Os
.Sh NAME
.Nm daemon
.Nd run detached from the controlling terminal
.Sh SYNOPSIS
.Nm
.Op Fl cf
.Op Fl p Ar pidfile
.Op Fl u Ar user
.Ar command arguments ...
.Sh DESCRIPTION
The
.Nm
utility detaches itself from the controlling terminal and
executes the program specified by its arguments.
Privileges may be lowered to the specified user.
.Pp
The options are as follows:
.Bl -tag -width indent
.It Fl c
Change the current working directory to the root
.Pq Dq Pa / .
.It Fl f
Redirect standard input, standard output and standard error to
.Pa /dev/null .
.It Fl p Ar file
Write the ID of the created process into the
.Ar file
using the
.Xr pidfile 3
functionality.
The program is executed in a spawned child process while the
.Nm
waits until it terminates to keep the
.Ar file
locked and removes it after the process exits.
The
.Ar file
owner is the user who runs the
.Nm
regardless of whether the
.Fl u
option is used or not.
.It Fl r
Supervise and restart the program if it has been terminated.
.It Fl u Ar user
Login name of the user to execute the program under.
Requires adequate superuser privileges.
.El
.Pp
If the
.Fl p
or
.Fl r
option is specified the program is executed in a spawned child process.
The
.Nm
waits until it terminates to keep the pid file locked and removes it
after the process exits or restarts the program.
In this case if the monitoring
.Nm
receives software termination signal (SIGTERM) it forwards it to the
spawned process.
Normally it will cause the child to exit followed by the termination
of the supervising process after removing the pidfile.
.Sh EXIT STATUS
The
.Nm
utility exits 1 if an error is returned by the
.Xr daemon 3
library routine, 2 if the
.Ar pidfile
is requested, but cannot be opened, 3 if process is already running (pidfile
exists and is locked),
otherwise 0.
.Sh DIAGNOSTICS
If the command cannot be executed, an error message is displayed on
standard error unless the
.Fl f
flag is specified.
.Sh SEE ALSO
.Xr setregid 2 ,
.Xr setreuid 2 ,
.Xr daemon 3 ,
.Xr exec 3 ,
.Xr pidfile 3 ,
.Xr termios 4 ,
.Xr tty 4
.Sh HISTORY
The
.Nm
utility first appeared in
.Fx 4.7 .