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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
     executes 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.
     Normally 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
     standard 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 11.0-PRERELEASE       September 13, 2013       FreeBSD 11.0-PRERELEASE

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

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