1.\" $OpenBSD: getgid.2,v 1.16 2008/08/04 07:08:23 jmc Exp $ 2.\" $NetBSD: getgid.2,v 1.5 1995/02/27 12:32:53 cgd Exp $ 3.\" 4.\" Copyright (c) 1983, 1991, 1993 5.\" The Regents of the University of California. All rights reserved. 6.\" 7.\" Redistribution and use in source and binary forms, with or without 8.\" modification, are permitted provided that the following conditions 9.\" are met: 10.\" 1. Redistributions of source code must retain the above copyright 11.\" notice, this list of conditions and the following disclaimer. 12.\" 2. Redistributions in binary form must reproduce the above copyright 13.\" notice, this list of conditions and the following disclaimer in the 14.\" documentation and/or other materials provided with the distribution. 15.\" 3. Neither the name of the University nor the names of its contributors 16.\" may be used to endorse or promote products derived from this software 17.\" without specific prior written permission. 18.\" 19.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29.\" SUCH DAMAGE. 30.\" 31.\" @(#)getgid.2 8.1 (Berkeley) 6/4/93 32.\" 33.Dd $Mdocdate: August 4 2008 $ 34.Dt GETGID 2 35.Os 36.Sh NAME 37.Nm getgid , 38.Nm getegid 39.Nd get group process identification 40.Sh SYNOPSIS 41.Fd #include <sys/types.h> 42.Fd #include <unistd.h> 43.Ft gid_t 44.Fn getgid void 45.Ft gid_t 46.Fn getegid void 47.Sh DESCRIPTION 48The 49.Fn getgid 50function returns the real group ID of the calling process and the 51.Fn getegid 52function returns the effective group ID of the calling process. 53.Pp 54The real group ID is specified at login time. 55.Pp 56The real group ID is the group of the user who invoked the program. 57As the effective group ID gives the process additional permissions 58during the execution of 59.Dq Em set-group-ID 60mode processes, 61.Fn getgid 62is used to determine the real group ID of the calling process. 63.Sh ERRORS 64The 65.Fn getgid 66and 67.Fn getegid 68functions are always successful, and no return value is reserved to 69indicate an error. 70.Sh SEE ALSO 71.Xr getgroups 2 , 72.Xr getresgid 2 , 73.Xr getuid 2 , 74.Xr setgid 2 , 75.Xr setregid 2 76.Sh STANDARDS 77The 78.Fn getgid 79and 80.Fn getegid 81functions conform to 82.St -p1003.1-88 . 83