1.\" Copyright (c) 1990, 1991 The Regents of the University of California. 2.\" 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.\" from: @(#)ctermid.3 5.2 (Berkeley) 4/19/91 29.\" $NetBSD: cuserid.3,v 1.13 2010/03/22 21:55:39 joerg Exp $ 30.\" 31.Dd November 28, 1993 32.Dt CUSERID 3 33.Os 34.Sh NAME 35.Nm cuserid 36.Nd get user name 37.Sh LIBRARY 38.Lb libcompat 39.Sh SYNOPSIS 40.In stdio.h 41.Ft char * 42.Fn cuserid "char *buf" 43.Sh DESCRIPTION 44.Bf -symbolic 45This interface is available from the compatibility library, libcompat and 46has been obsoleted by 47.Xr getlogin 2 . 48.Ef 49.Pp 50The 51.Fn cuserid 52function returns a character string representation of the user name 53associated with the effective user ID of the calling process. 54.Pp 55If 56.Fa buf 57is not the 58.Dv NULL 59pointer, the user name is copied into the memory referenced by 60.Fa buf . 61The argument 62.Fa buf 63is assumed to point to an array at least 64.Dv L_cuserid 65(as defined in the include 66file 67.In stdio.h ) 68bytes long. 69Otherwise, the user name is copied to a static buffer. 70.Sh RETURN VALUES 71If 72.Fa buf 73is not the 74.Dv NULL 75pointer, 76.Fa buf 77is returned; 78otherwise the address of the static buffer is returned. 79.Pp 80If the user name could not be determined, if 81.Fa buf 82is not the 83.Dv NULL 84pointer, the null character 85.Sq \e0 86will be stored at 87.Fa *buf ; 88otherwise 89the 90.Dv NULL 91pointer is returned. 92.Sh SEE ALSO 93.Xr getlogin 2 , 94.Xr getpwent 3 95.Sh STANDARDS 96The 97.Fn cuserid 98function conforms to 99.St -p1003.1-88 . 100.Sh BUGS 101Due to irreconcilable differences in historic implementations, 102.Fn cuserid 103was removed from the 104.St -p1003.1-90 105standard. 106This implementation exists purely for compatibility with existing programs. 107New programs should use one of the following three alternatives to 108obtain the user name: 109.Pp 110.Bl -enum -offset indent -compact 111.It 112.Fn getlogin 113to return the user's login name. 114.It 115.Nm getpwuid Ns Pq Fn geteuid 116to return the user name associated with the calling process' effective user ID. 117.It 118.Nm getpwuid Ns Pq Fn getuid 119to return the user name associated with the calling process' real user ID. 120.El 121