.\"	$OpenBSD: getuid.2,v 1.15 2013/03/30 06:44:44 guenther Exp $
.\"	$NetBSD: getuid.2,v 1.6 1995/02/27 12:33:37 cgd Exp $
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.\"     @(#)getuid.2	8.1 (Berkeley) 6/4/93
.\"
.Dd $Mdocdate: March 30 2013 $
.Dt GETUID 2
.Os
.Sh NAME
.Nm getuid ,
.Nm geteuid
.Nd get user identification
.Sh SYNOPSIS
.Fd #include <unistd.h>
.Ft uid_t
.Fn getuid void
.Ft uid_t
.Fn geteuid void
.Sh DESCRIPTION
The
.Fn getuid
function returns the real user ID of the calling process.
The
.Fn geteuid
function returns the effective user ID of the calling process.
.Pp
The real user ID is that of the user who has invoked the program.
As the effective user ID
gives the process additional permissions during
execution of
.Dq Em set-user-ID
mode processes,
.Fn getuid
is used to determine the real user ID of the calling process.
.Sh ERRORS
The
.Fn getuid
and
.Fn geteuid
functions are always successful, and no return value is reserved to
indicate an error.
.Sh SEE ALSO
.Xr getgid 2 ,
.Xr getresuid 2 ,
.Xr setreuid 2 ,
.Xr setuid 2
.Sh STANDARDS
The
.Fn getuid
and
.Fn geteuid
functions conform to
.St -p1003.1-2008 .
.Sh HISTORY
The
.Fn getuid
system call first appeared in
.At v1 ,
and
.Fn geteuid
in
.At v7 .