getgid, getegid — get group identity

Synopsis

#include <unistd.h>
#include <sys/types.h>

gid_t getgid(void);
gid_t getegid(void);

Description

getgid() returns the real group ID of the calling process.

getegid() returns the effective group ID of the calling process.

Errors

These functions are always successful.

Conforming to

POSIX.1-2001, POSIX.1-2008, 4.3BSD.

Notes

The original Linux getgid() and getegid() system calls supported only 16-bit group IDs. Subsequently, Linux 2.4 added getgid32() and getegid32(), supporting 32-bit IDs. The glibc getgid() and getegid() wrapper functions transparently deal with the variations across kernel versions.

On Alpha, instead of a pair of getgid() and getegid() system calls, a single getxgid() system call is provided, which returns a pair of real and effective GIDs. The glibc getgid() and getegid() wrapper functions transparently deal with this. See syscall(2) for details regarding register mapping.

See Also

getresgid(2), setgid(2), setregid(2), credentials(7)

Colophon

This page is part of release 5.04 of the Linux man-pages project. A description of the project, information about reporting bugs, and the latest version of this page, can be found at https://www.kernel.org/doc/man-pages/.

Referenced By

credentials(7), gawk(1), getgroups(2), group_member(3), mksh(1), procenv(1), ps(1), setgid(2), setreuid(2), signal-safety(7), strace(1), syscalls(2), user_namespaces(7).

The man pages getegid(2), getegid32(2) and getgid32(2) are aliases of getgid(2).

2019-03-06 Linux Programmer's Manual