1.\" $NetBSD: setsid.2,v 1.9 2002/04/29 01:41:45 simonb Exp $ 2.\" 3.\" Copyright (c) 1991, 1993 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. All advertising materials mentioning features or use of this software 15.\" must display the following acknowledgement: 16.\" This product includes software developed by the University of 17.\" California, Berkeley and its contributors. 18.\" 4. Neither the name of the University nor the names of its contributors 19.\" may be used to endorse or promote products derived from this software 20.\" without specific prior written permission. 21.\" 22.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32.\" SUCH DAMAGE. 33.\" 34.\" @(#)setsid.2 8.1 (Berkeley) 6/4/93 35.\" 36.Dd June 4, 1993 37.Dt SETSID 2 38.Os 39.Sh NAME 40.Nm setsid 41.Nd create session and set process group ID 42.Sh LIBRARY 43.Lb libc 44.Sh SYNOPSIS 45.Fd #include \*[Lt]unistd.h\*[Gt] 46.Ft pid_t 47.Fn setsid "void" 48.Sh DESCRIPTION 49The 50.Nm setsid 51function creates a new session. 52The calling process is the session leader of the new session, is the 53process group leader of a new process group and has no controlling 54terminal. 55The calling process is the only process in either the session or the 56process group. 57.Pp 58Upon successful completion, the 59.Nm setsid 60function returns the value of the process group ID of the new process 61group, which is the same as the process ID of the calling process. 62.Sh ERRORS 63If an error occurs, 64.Nm setsid 65returns -1 and the global variable 66.Va errno 67is set to indicate the error, as follows: 68.Bl -tag -width Er 69.It Bq Er EPERM 70The calling process is already a process group leader, or the process 71group ID of a process other than the calling process matches the process 72ID of the calling process. 73.El 74.Sh SEE ALSO 75.Xr setpgid 2 , 76.Xr tcgetpgrp 3 , 77.Xr tcsetpgrp 3 78.Sh STANDARDS 79The 80.Nm setsid 81function conforms to 82.St -p1003.1-90 . 83