1.\" $NetBSD: getuid.2,v 1.17 2010/04/05 07:44:28 wiz Exp $ 2.\" 3.\" Copyright (c) 1980, 1991, 1993 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. Neither the name of the University nor the names of its contributors 15.\" may be used to endorse or promote products derived from this software 16.\" without specific prior written permission. 17.\" 18.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 19.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28.\" SUCH DAMAGE. 29.\" 30.\" @(#)getuid.2 8.1 (Berkeley) 6/4/93 31.\" 32.Dd April 3, 2010 33.Dt GETUID 2 34.Os 35.Sh NAME 36.Nm getuid , 37.Nm geteuid 38.Nd get user identification 39.Sh LIBRARY 40.Lb libc 41.Sh SYNOPSIS 42.In unistd.h 43.Ft uid_t 44.Fn getuid void 45.Ft uid_t 46.Fn geteuid void 47.Sh DESCRIPTION 48The 49.Fn getuid 50function returns the real user ID of the calling process. 51The 52.Fn geteuid 53function 54returns the effective user ID of the calling process. 55.Pp 56The real user ID is that of the user who has invoked the program. 57As the effective user ID 58gives the process additional permissions during 59execution of 60.Dq Em set-user-ID 61mode processes, 62.Fn getuid 63is used to determine the real-user-id of the calling process. 64.Sh ERRORS 65The 66.Fn getuid 67and 68.Fn geteuid 69functions are always successful, and no return value is reserved to 70indicate an error. 71.Sh SEE ALSO 72.Xr getgid 2 , 73.Xr setreuid 2 74.Sh STANDARDS 75The 76.Fn geteuid 77and 78.Fn getuid 79functions conform to 80.St -p1003.1-90 . 81.Sh HISTORY 82The 83.Fn getuid 84function appeared in 85.At v4 . 86