opendarwin man page for getgid

GETGID(2)						      BSD System Calls Manual							 GETGID(2)

NAME
     getgid, getegid -- get group process identification

SYNOPSIS
     #include <sys/types.h>
     #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 dur-
     ing the execution of ``set-group-ID'' mode processes, getgid() is used to determine the real-user-id of the calling process.

ERRORS
     The getgid() and getegid() functions are always successful, and no return value is reserved to indicate an error.

SEE ALSO
     getuid(2), setregid(2), setgid(3)

STANDARDS
     Getgid() and getegid() conform to IEEE Std 1003.1-1988 (``POSIX.1'').

4.2 Berkeley Distribution					   June 4, 1993 					 4.2 Berkeley Distribution