1.\" $NetBSD: getgid.2,v 1.19 2010/04/03 15:13:43 jruoho Exp $ 2.\" 3.\" Copyright (c) 1983, 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. Neither the name of the University nor the names of its contributors 15.\" may be used to endorse or promote products derived from this software 16.\" without specific prior written permission. 17.\" 18.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 19.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28.\" SUCH DAMAGE. 29.\" 30.\" @(#)getgid.2 8.1 (Berkeley) 6/4/93 31.\" 32.Dd April 3, 2010 33.Dt GETGID 2 34.Os 35.Sh NAME 36.Nm getgid , 37.Nm getegid 38.Nd get group process identification 39.Sh LIBRARY 40.Lb libc 41.Sh SYNOPSIS 42.In 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, 51.Fn getegid 52returns 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 getuid 2 , 72.Xr setgid 2 , 73.Xr setgroups 2 , 74.Xr setregid 2 75.Sh STANDARDS 76.Fn getgid 77and 78.Fn getegid 79conform to 80.St -p1003.1-90 . 81.Sh HISTORY 82The 83.Fn getgid 84function appeared in 85.At v4 . 86