.\" $NetBSD: setsid.2,v 1.3 1995/10/12 15:41:13 jtc Exp $ .\" .\" Copyright (c) 1991, 1993 .\" The Regents of the University of California. All rights reserved. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in the .\" documentation and/or other materials provided with the distribution. .\" 3. All advertising materials mentioning features or use of this software .\" must display the following acknowledgement: .\" This product includes software developed by the University of .\" California, Berkeley and its contributors. .\" 4. Neither the name of the University nor the names of its contributors .\" may be used to endorse or promote products derived from this software .\" without specific prior written permission. .\" .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" .\" @(#)setsid.2 8.1 (Berkeley) 6/4/93 .\" .Dd June 4, 1993 .Dt SETSID 2 .Os .Sh NAME .Nm setsid .Nd create session and set process group ID .Sh SYNOPSIS .Fd #include <unistd.h> .Ft pid_t .Fo setsid .Fa void .Fc .Sh DESCRIPTION The .Nm setsid function creates a new session. The calling process is the session leader of the new session, is the process group leader of a new process group and has no controlling terminal. The calling process is the only process in either the session or the process group. .Pp Upon successful completion, the .Nm setsid function returns the value of the process group ID of the new process group, which is the same as the process ID of the calling process. .Sh ERRORS If an error occurs, .Nm setsid returns -1 and the global variable .Va errno is set to indicate the error, as follows: .Bl -tag -width Er .It Bq Er EPERM The calling process is already a process group leader, or the process group ID of a process other than the calling process matches the process ID of the calling process. .El .Sh LEGACY SYNOPSIS .Fd #include <sys/types.h> .Fd #include <unistd.h> .Pp The include file .In sys/types.h is necessary. .Sh SEE ALSO .Xr setpgid 3 , .Xr tcgetpgrp 3 , .Xr tcsetpgrp 3 , .Xr compat 5 .Sh STANDARDS The .Nm setsid function is expected to be compliant with the .St -p1003.1-88 specification.