1.\" Copyright (c) 1980, 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. Neither the name of the University nor the names of its contributors 13.\" may be used to endorse or promote products derived from this software 14.\" without specific prior written permission. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26.\" SUCH DAMAGE. 27.\" 28.\" @(#)setpgid.2 8.1 (Berkeley) 6/4/93 29.\" $FreeBSD$ 30.\" 31.Dd February 8, 2004 32.Dt SETPGID 2 33.Os 34.Sh NAME 35.Nm setpgid , 36.Nm setpgrp 37.Nd set process group 38.Sh LIBRARY 39.Lb libc 40.Sh SYNOPSIS 41.In unistd.h 42.Ft int 43.Fn setpgid "pid_t pid" "pid_t pgrp" 44.Ft int 45.Fn setpgrp "pid_t pid" "pid_t pgrp" 46.Sh DESCRIPTION 47The 48.Fn setpgid 49system call 50sets the process group of the specified process 51.Fa pid 52to the specified 53.Fa pgrp . 54If 55.Fa pid 56is zero, then the call applies to the current process. 57If 58.Fa pgrp 59is zero, then the process id of the process specified by 60.Fa pid 61is used instead. 62.Pp 63If the affected process is not the invoking process, then it must be a 64child of the invoking process, it must not have performed an 65.Xr exec 3 66operation, and both processes must be in the same session. 67The requested process group ID must already exist in the session of 68the caller, or it must be equal to the target process ID. 69.Sh RETURN VALUES 70.Rv -std setpgid 71.Sh COMPATIBILITY 72The 73.Fn setpgrp 74system call 75is identical to 76.Fn setpgid , 77and is retained for calling convention compatibility with historical 78versions of 79.Bx . 80.Sh ERRORS 81The 82.Fn setpgid 83system call 84will fail and the process group will not be altered if: 85.Bl -tag -width Er 86.It Bq Er EINVAL 87The requested process group ID is not legal. 88.It Bq Er ESRCH 89The requested process does not exist. 90.It Bq Er ESRCH 91The target process is not the calling process or 92a child of the calling process. 93.It Bq Er EACCES 94The requested process is a child of the calling process, 95but it has performed an 96.Xr exec 3 97operation. 98.It Bq Er EPERM 99The target process is a session leader. 100.It Bq Er EPERM 101The requested process group ID is not in the session of the caller, 102and it is not equal to the process ID of the target process. 103.El 104.Sh SEE ALSO 105.Xr getpgrp 2 106.Sh STANDARDS 107The 108.Fn setpgid 109system call is expected to conform to 110.St -p1003.1-90 . 111