1.\" Copyright (c) 1980, 1991, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 3. Neither the name of the University nor the names of its contributors 13.\" may be used to endorse or promote products derived from this software 14.\" without specific prior written permission. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26.\" SUCH DAMAGE. 27.\" 28.\" @(#)getuid.2 8.1 (Berkeley) 6/4/93 29.\" $FreeBSD: src/lib/libc/sys/getuid.2,v 1.7.2.4 2001/12/14 18:34:00 ru Exp $ 30.\" $DragonFly: src/lib/libc/sys/getuid.2,v 1.2 2003/06/17 04:26:47 dillon Exp $ 31.\" 32.Dd June 4, 1993 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.In sys/types.h 44.Ft uid_t 45.Fn getuid void 46.Ft uid_t 47.Fn geteuid void 48.Sh DESCRIPTION 49The 50.Fn getuid 51function returns the real user ID of the calling process. 52The 53.Fn geteuid 54function 55returns the effective user ID of the calling process. 56.Pp 57The real user ID is that of the user who has invoked the program. 58As the effective user ID 59gives the process additional permissions during 60execution of 61.Dq Em set-user-ID 62mode processes, 63.Fn getuid 64is used to determine the real-user-id of the calling process. 65.Sh ERRORS 66The 67.Fn getuid 68and 69.Fn geteuid 70functions are always successful, and no return value is reserved to 71indicate an error. 72.Sh SEE ALSO 73.Xr getgid 2 , 74.Xr issetugid 2 , 75.Xr setgid 2 , 76.Xr setreuid 2 , 77.Xr setuid 2 78.Sh STANDARDS 79The 80.Fn geteuid 81and 82.Fn getuid 83function calls are expected to conform to 84.St -p1003.1-90 . 85.Sh HISTORY 86A 87.Fn getuid 88and a 89.Fn geteuid 90function call appeared in 91.At v7 . 92