1.\" Copyright (c) 1983, 1991, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" %sccs.include.redist.man% 5.\" 6.\" @(#)getgid.2 8.1 (Berkeley) 06/04/93 7.\" 8.Dd 9.Dt GETGID 2 10.Os BSD 4.2 11.Sh NAME 12.Nm getgid , 13.Nm getegid 14.Nd get group process identification 15.Sh SYNOPSIS 16.Fd #include <sys/types.h> 17.Ft gid_t 18.Fn getgid void 19.Ft gid_t 20.Fn getegid void 21.Sh DESCRIPTION 22The 23.Fn getgid 24function returns the real group ID of the calling process, 25.Fn getegid 26returns the effective group ID of the calling process. 27.Pp 28The real group ID is specified at login time. 29.Pp 30The real group ID is the group of the user who invoked the program. 31As the effective group ID gives the process additional permissions 32during the execution of 33.Dq Em set-group-ID 34mode processes, 35.Fn getgid 36is used to determine the real-user-id of the calling process. 37.Sh ERRORS 38The 39.Fn getgid 40and 41.Fn getegid 42functions are always successful, and no return value is reserved to 43indicate an error. 44.Sh SEE ALSO 45.Xr getuid 2 , 46.Xr setregid 2 , 47.Xr setgid 3 48.Sh STANDARDS 49.Fn Getgid 50and 51.Fn getegid 52conform to IEEE Std 1003.1-1988 53.Pq Dq Tn POSIX . 54