1.\" $NetBSD: getgid.2,v 1.14 2002/04/29 01:41:45 simonb 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 39.Sh NAME 40.Nm getgid , 41.Nm getegid 42.Nd get group process identification 43.Sh LIBRARY 44.Lb libc 45.Sh SYNOPSIS 46.Fd #include \*[Lt]unistd.h\*[Gt] 47.Ft gid_t 48.Fn getgid void 49.Ft gid_t 50.Fn getegid void 51.Sh DESCRIPTION 52The 53.Fn getgid 54function returns the real group ID of the calling process, 55.Fn getegid 56returns the effective group ID of the calling process. 57.Pp 58The real group ID is specified at login time. 59.Pp 60The real group ID is the group of the user who invoked the program. 61As the effective group ID gives the process additional permissions 62during the execution of 63.Dq Em set-group-ID 64mode processes, 65.Fn getgid 66is used to determine the real-group-id of the calling process. 67.Sh ERRORS 68The 69.Fn getgid 70and 71.Fn getegid 72functions are always successful, and no return value is reserved to 73indicate an error. 74.Sh SEE ALSO 75.Xr getuid 2 , 76.Xr setgid 2 , 77.Xr setregid 2 78.Sh STANDARDS 79.Fn getgid 80and 81.Fn getegid 82conform to 83.St -p1003.1-90 . 84