1.\" Copyright (c) 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 3. All advertising materials mentioning features or use of this software 13.\" must display the following acknowledgement: 14.\" This product includes software developed by the University of 15.\" California, Berkeley and its contributors. 16.\" 4. Neither the name of the University nor the names of its contributors 17.\" may be used to endorse or promote products derived from this software 18.\" without specific prior written permission. 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.\" @(#)daemon.3 8.1 (Berkeley) 6/9/93 33.\" $FreeBSD$ 34.\" 35.Dd June 9, 1993 36.Dt DAEMON 3 37.Os 38.Sh NAME 39.Nm daemon 40.Nd run in the background 41.Sh SYNOPSIS 42.Fd #include <stdlib.h> 43.Ft int 44.Fn daemon "int nochdir" "int noclose" 45.Sh DESCRIPTION 46.Pp 47The 48.Fn daemon 49function is for programs wishing to detach themselves from the 50controlling terminal and run in the background as system daemons. 51.Pp 52Unless the argument 53.Fa nochdir 54is non-zero, 55.Fn daemon 56changes the current working directory to the root (``/''). 57.Pp 58Unless the argument 59.Fa noclose 60is non-zero, 61.Fn daemon 62will redirect standard input, standard output and standard error 63to ``/dev/null''. 64.Sh ERRORS 65If an error occurs, 66.Fn daemon 67returns -1 and sets the global variable 68.Va errno 69to any of the errors specified for the library functions 70.Xr fork 2 71and 72.Xr setsid 2 . 73.Sh SEE ALSO 74.Xr fork 2 , 75.Xr setsid 2 76.Sh HISTORY 77The 78.Fn daemon 79function first appeared in 80.Bx 4.4 . 81