| GETGID(2) | System Calls Manual | GETGID(2) | 
NAME
 getgid, getegid — get group process identification
LIBRARY
 Standard C Library (libc, -lc)
SYNOPSIS
 #include <unistd.h>
gid_t
getgid(void);
gid_t
getegid(void);
 
DESCRIPTION
 The 
getgid() function returns the real group ID of the calling process, 
getegid() returns the effective group ID of the calling process.
The real group ID is specified at login time.
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 “set-group-ID” mode processes, getgid() is used to determine the real-group-id of the calling process.
 
ERRORS
 The getgid() and getegid() functions are always successful, and no return value is reserved to indicate an error.
STANDARDS
 getgid() and getegid() conform to IEEE Std 1003.1-1990 (“POSIX.1”).
HISTORY
 The getgid() function appeared in Version 4 AT&T UNIX.