.\" Copyright 1993 Rickard E. Faith (faith@cs.unc.edu)
.\"
.\" SPDX-License-Identifier: Linux-man-pages-copyleft
.\"
.TH getgid 2 2023-10-31 "Linux man-pages 6.06"
.SH NAME
getgid, getegid \- get group identity
.SH LIBRARY
Standard C library
.RI ( libc ", " \-lc )
.SH SYNOPSIS
.nf
.B #include <unistd.h>
.P
.B gid_t getgid(void);
.B gid_t getegid(void);
.fi
.SH DESCRIPTION
.BR getgid ()
returns the real group ID of the calling process.
.P
.BR getegid ()
returns the effective group ID of the calling process.
.SH ERRORS
These functions are always successful
and never modify
.\" https://www.austingroupbugs.net/view.php?id=511
.\" 0000511: getuid and friends should not modify errno
.IR errno .
.SH VERSIONS
On Alpha, instead of a pair of
.BR getgid ()
and
.BR getegid ()
system calls, a single
.BR getxgid ()
system call is provided, which returns a pair of real and effective GIDs.
The glibc
.BR getgid ()
and
.BR getegid ()
wrapper functions transparently deal with this.
See
.BR syscall (2)
for details regarding register mapping.
.SH STANDARDS
POSIX.1-2008.
.SH HISTORY
POSIX.1-2001, 4.3BSD.
.P
The original Linux
.BR getgid ()
and
.BR getegid ()
system calls supported only 16-bit group IDs.
Subsequently, Linux 2.4 added
.BR getgid32 ()
and
.BR getegid32 (),
supporting 32-bit IDs.
The glibc
.BR getgid ()
and
.BR getegid ()
wrapper functions transparently deal with the variations across kernel versions.
.SH SEE ALSO
.BR getresgid (2),
.BR setgid (2),
.BR setregid (2),
.BR credentials (7)