1.\" Copyright (c) 1999 Berkeley Software Design, Inc. All rights reserved. 2.\" 3.\" Redistribution and use in source and binary forms, with or without 4.\" modification, are permitted provided that the following conditions 5.\" are met: 6.\" 1. Redistributions of source code must retain the above copyright 7.\" notice, this list of conditions and the following disclaimer. 8.\" 2. Redistributions in binary form must reproduce the above copyright 9.\" notice, this list of conditions and the following disclaimer in the 10.\" documentation and/or other materials provided with the distribution. 11.\" 3. Berkeley Software Design Inc's name may not be used to endorse or 12.\" promote products derived from this software without specific prior 13.\" written permission. 14.\" 15.\" THIS SOFTWARE IS PROVIDED BY BERKELEY SOFTWARE DESIGN INC ``AS IS'' AND 16.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18.\" ARE DISCLAIMED. IN NO EVENT SHALL BERKELEY SOFTWARE DESIGN INC BE LIABLE 19.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25.\" SUCH DAMAGE. 26.\" 27.\" $FreeBSD: head/usr.sbin/daemon/daemon.8 255526 2013-09-13 19:19:21Z joel $ 28.\" 29.Dd September 13, 2013 30.Dt DAEMON 8 31.Os 32.Sh NAME 33.Nm daemon 34.Nd run detached from the controlling terminal 35.Sh SYNOPSIS 36.Nm 37.Op Fl cfr 38.Op Fl p Ar child_pidfile 39.Op Fl P Ar supervisor_pidfile 40.Op Fl u Ar user 41.Ar command arguments ... 42.Sh DESCRIPTION 43The 44.Nm 45utility detaches itself from the controlling terminal and 46executes the program specified by its arguments. 47Privileges may be lowered to the specified user. 48.Pp 49The options are as follows: 50.Bl -tag -width indent 51.It Fl c 52Change the current working directory to the root 53.Pq Dq Pa / . 54.It Fl f 55Redirect standard input, standard output and standard error to 56.Pa /dev/null . 57.It Fl p Ar child_pidfile 58Write the ID of the created process into the 59.Ar child_pidfile 60using the 61.Xr pidfile 3 62functionality. 63The program is executed in a spawned child process while the 64.Nm 65waits until it terminates to keep the 66.Ar child_pidfile 67locked and removes it after the process exits. 68The 69.Ar child_pidfile 70owner is the user who runs the 71.Nm 72regardless of whether the 73.Fl u 74option is used or not. 75.It Fl P Ar supervisor_pidfile 76Write the ID of the 77.Nm 78process into the 79.Ar supervisor_pidfile 80using the 81.Xr pidfile 3 82functionality. 83The program is executed in a spawned child process while the 84.Nm 85waits until it terminates to keep the 86.Ar supervisor_pidfile 87locked and removes it after the process exits. 88The 89.Ar supervisor_pidfile 90owner is the user who runs the 91.Nm 92regardless of whether the 93.Fl u 94option is used or not. 95.It Fl r 96Supervise and restart the program if it has been terminated. 97.It Fl u Ar user 98Login name of the user to execute the program under. 99Requires adequate superuser privileges. 100.El 101.Pp 102If the 103.Fl p , 104.Fl P 105or 106.Fl r 107option is specified the program is executed in a spawned child process. 108The 109.Nm 110waits until it terminates to keep the pid file(s) locked and removes them 111after the process exits or restarts the program. 112In this case if the monitoring 113.Nm 114receives software termination signal (SIGTERM) it forwards it to the 115spawned process. 116Normally it will cause the child to exit, remove the pidfile(s) 117and then terminate. 118.Pp 119The 120.Fl P 121option is useful combined with the 122.Fl r 123option as 124.Ar supervisor_pidfile 125contains the ID of the supervisor 126not the child. This is especially important if you use 127.Fl r 128in an rc script as the 129.Fl p 130option will give you the child's ID to signal when you attempt to 131stop the service, causing 132.Nm 133to restart the child. 134.Sh EXIT STATUS 135The 136.Nm 137utility exits 1 if an error is returned by the 138.Xr daemon 3 139library routine, 2 if 140.Ar child_pidfile 141or 142.Ar supervisor_pidfile 143is requested, but cannot be opened, 3 if process is already running (pidfile 144exists and is locked), 145otherwise 0. 146.Sh DIAGNOSTICS 147If the command cannot be executed, an error message is displayed on 148standard error unless the 149.Fl f 150flag is specified. 151.Sh SEE ALSO 152.Xr setregid 2 , 153.Xr setreuid 2 , 154.Xr daemon 3 , 155.Xr exec 3 , 156.Xr pidfile 3 , 157.Xr termios 4 , 158.Xr tty 4 159.Sh HISTORY 160The 161.Nm 162utility first appeared in 163.Fx 4.7 . 164