.\"	$OpenBSD: getgid.2,v 1.15 2007/05/31 19:19:32 jmc Exp $
.\"	$NetBSD: getgid.2,v 1.5 1995/02/27 12:32:53 cgd Exp $
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.\"     @(#)getgid.2	8.1 (Berkeley) 6/4/93
.\"
.Dd $Mdocdate: May 31 2007 $
.Dt GETGID 2
.Os
.Sh NAME
.Nm getgid ,
.Nm getegid
.Nd get group process identification
.Sh SYNOPSIS
.Fd #include <sys/types.h>
.Fd #include <unistd.h>
.Ft gid_t
.Fn getgid void
.Ft gid_t
.Fn getegid void
.Sh DESCRIPTION
The
.Fn getgid
function returns the real group ID of the calling process and the
.Fn getegid
function returns the effective group ID of the calling process.
.Pp
The real group ID is specified at login time.
.Pp
The real group ID is the group of the user who invoked the program.
As the effective group ID gives the process additional permissions
during the execution of
.Dq Em set-group-ID
mode processes,
.Fn getgid
is used to determine the real group ID of the calling process.
.Sh ERRORS
The
.Fn getgid
and
.Fn getegid
functions are always successful, and no return value is reserved to
indicate an error.
.Sh SEE ALSO
.Xr getuid 2 ,
.Xr setgid 2 ,
.Xr setgroups 2 ,
.Xr setregid 2 ,
.Xr setreuid 2
.Sh STANDARDS
The
.Fn getgid
and
.Fn getegid
functions conform to
.St -p1003.1-88 .