1.\" Copyright (c) 1991, 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.\" @(#)setsid.2 8.1 (Berkeley) 6/4/93 33.\" 34.Dd "June 4, 1993" 35.Dt SETSID 2 36.Os 37.Sh NAME 38.Nm setsid 39.Nd create session and set process group ID 40.Sh SYNOPSIS 41.Fd #include <sys/types.h> 42.Ft pid_t 43.Fn setsid "void" 44.Sh DESCRIPTION 45The 46.Nm setsid 47function creates a new session. 48The calling process is the session leader of the new session, is the 49process group leader of a new process group and has no controlling 50terminal. 51The calling process is the only process in either the session or the 52process group. 53.Pp 54Upon successful completion, the 55.Nm setsid 56function returns the value of the process group ID of the new process 57group, which is the same as the process ID of the calling process. 58.Sh ERRORS 59If an error occurs, 60.Nm setsid 61returns -1 and the global variable 62.Va errno 63is set to indicate the error, as follows: 64.Bl -tag -width Er 65.It Bq Er EPERM 66The calling process is already a process group leader, or the process 67group ID of a process other than the calling process matches the process 68ID of the calling process. 69.El 70.Sh SEE ALSO 71.Xr setpgid 3 , 72.Xr tcgetpgrp 3 , 73.Xr tcsetpgrp 3 74.Sh STANDARDS 75The 76.Nm setsid 77function is expected to be compliant with the 78.St -p1003.1-88 79specification. 80