GETGID(2) Linux Programmer's Manual GETGID(2)
getgid, getegid - get group identity
#include <unistd.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 and never modify errno.
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)
This page is part of release 5.13 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/. Linux 2021-03-22 GETGID(2)
Pages that refer to this page: groups(1@@shadow-utils), ps(1), strace(1), getgroups(2), setgid(2), setreuid(2), syscalls(2), group_member(3), credentials(7), signal-safety(7), system_data_types(7), user_namespaces(7)
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