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DAEMON(8)		FreeBSD	System Manager's Manual		     DAEMON(8)

NAME
     daemon -- run detached from the controlling terminal

SYNOPSIS
     daemon [-cfr] [-p child_pidfile] [-P supervisor_pidfile] [-u user]
	    command arguments ...

DESCRIPTION
     The daemon	utility	detaches itself	from the controlling terminal and exe-
     cutes the program specified by its	arguments.  Privileges may be lowered
     to	the specified user.

     The options are as	follows:

     -c	     Change the	current	working	directory to the root (``/'').

     -f	     Redirect standard input, standard output and standard error to
	     /dev/null.

     -p	child_pidfile
	     Write the ID of the created process into the child_pidfile	using
	     the pidfile(3) functionality.  The	program	is executed in a
	     spawned child process while the daemon waits until	it terminates
	     to	keep the child_pidfile locked and removes it after the process
	     exits.  The child_pidfile owner is	the user who runs the daemon
	     regardless	of whether the -u option is used or not.

     -P	supervisor_pidfile
	     Write the ID of the daemon	process	into the supervisor_pidfile
	     using the pidfile(3) functionality.  The program is executed in a
	     spawned child process while the daemon waits until	it terminates
	     to	keep the supervisor_pidfile locked and removes it after	the
	     process exits.  The supervisor_pidfile owner is the user who runs
	     the daemon	regardless of whether the -u option is used or not.

     -r	     Supervise and restart the program if it has been terminated.

     -u	user
	     Login name	of the user to execute the program under.  Requires
	     adequate superuser	privileges.

     If	the -p,	-P or -r option	is specified the program is executed in	a
     spawned child process.  The daemon	waits until it terminates to keep the
     pid file(s) locked	and removes them after the process exits or restarts
     the program.  In this case	if the monitoring daemon receives software
     termination signal	(SIGTERM) it forwards it to the	spawned	process.  Nor-
     mally it will cause the child to exit, remove the pidfile(s) and then
     terminate.

     The -P option is useful combined with the -r option as supervisor_pidfile
     contains the ID of	the supervisor not the child. This is especially
     important if you use -r in	an rc script as	the -p option will give	you
     the child's ID to signal when you attempt to stop the service, causing
     daemon to restart the child.

EXIT STATUS
     The daemon	utility	exits 1	if an error is returned	by the daemon(3)
     library routine, 2	if child_pidfile or supervisor_pidfile is requested,
     but cannot	be opened, 3 if	process	is already running (pidfile exists and
     is	locked), otherwise 0.

DIAGNOSTICS
     If	the command cannot be executed,	an error message is displayed on stan-
     dard error	unless the -f flag is specified.

SEE ALSO
     setregid(2), setreuid(2), daemon(3), exec(3), pidfile(3), termios(4),
     tty(4)

HISTORY
     The daemon	utility	first appeared in FreeBSD 4.7.

FreeBSD	10.1		      September	13, 2013		  FreeBSD 10.1

NAME | SYNOPSIS | DESCRIPTION | EXIT STATUS | DIAGNOSTICS | SEE ALSO | HISTORY

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