getgid, getegid - get group identity
#include <unistd.h>
#include <sys/types.h>
gid_t getgid(void);
gid_t getegid(void);
getgid() returns the real group ID of the calling process.
getegid() returns the effective group ID of the calling process.
These functions are always successful.
POSIX.1-2001, POSIX.1-2008, 4.3BSD.
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.
getresgid(2),
setgid(2),
setregid(2),
credentials(7)