1.\" $NetBSD: getgid.2,v 1.5 1995/02/27 12:32:53 cgd 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. All advertising materials mentioning features or use of this software 15.\" must display the following acknowledgement: 16.\" This product includes software developed by the University of 17.\" California, Berkeley and its contributors. 18.\" 4. Neither the name of the University nor the names of its contributors 19.\" may be used to endorse or promote products derived from this software 20.\" without specific prior written permission. 21.\" 22.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32.\" SUCH DAMAGE. 33.\" 34.\" @(#)getgid.2 8.1 (Berkeley) 6/4/93 35.\" 36.Dd June 4, 1993 37.Dt GETGID 2 38.Os BSD 4.2 39.Sh NAME 40.Nm getgid , 41.Nm getegid 42.Nd get group process identification 43.Sh SYNOPSIS 44.Fd #include <sys/types.h> 45.Fd #include <unistd.h> 46.Ft gid_t 47.Fn getgid void 48.Ft gid_t 49.Fn getegid void 50.Sh DESCRIPTION 51The 52.Fn getgid 53function returns the real group ID of the calling process, 54.Fn getegid 55returns the effective group ID of the calling process. 56.Pp 57The real group ID is specified at login time. 58.Pp 59The real group ID is the group of the user who invoked the program. 60As the effective group ID gives the process additional permissions 61during the execution of 62.Dq Em set-group-ID 63mode processes, 64.Fn getgid 65is used to determine the real-user-id of the calling process. 66.Sh ERRORS 67The 68.Fn getgid 69and 70.Fn getegid 71functions are always successful, and no return value is reserved to 72indicate an error. 73.Sh SEE ALSO 74.Xr getuid 2 , 75.Xr setregid 2 , 76.Xr setgid 3 77.Sh STANDARDS 78.Fn Getgid 79and 80.Fn getegid 81conform to 82.St -p1003.1-88 . 83