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. All advertising materials mentioning features or use of this software 13.\" must display the following acknowledgement: 14.\" This product includes software developed by the University of 15.\" California, Berkeley and its contributors. 16.\" 4. Neither the name of the University nor the names of its contributors 17.\" may be used to endorse or promote products derived from this software 18.\" without specific prior written permission. 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.\" from: @(#)ctermid.3 5.2 (Berkeley) 4/19/91 33.\" $NetBSD: cuserid.3,v 1.8 2002/02/07 07:00:35 ross Exp $ 34.\" 35.Dd November 28, 1993 36.Dt CUSERID 3 37.Os 38.Sh NAME 39.Nm cuserid 40.Nd get user name 41.Sh LIBRARY 42.Lb libcompat 43.Sh SYNOPSIS 44.Fd #include \*[Lt]stdio.h\*[Gt] 45.Ft char * 46.Fn cuserid "char *buf" 47.Sh DESCRIPTION 48.Bf -symbolic 49This interface is available from the compatibility library, libcompat and 50has been obsoleted by 51.Xr getlogin 2 52.Ef 53.Pp 54The 55.Fn cuserid 56function returns a character string representation of the user name 57associated with the effective user ID of the calling process. 58.Pp 59If 60.Fa buf 61is not the 62.Dv NULL 63pointer, the user name is copied into the memory referenced by 64.Fa buf . 65The argument 66.Fa buf 67is assumed to point to an array at least 68.Dv L_cuserid 69(as defined in the include 70file 71.Aq Pa stdio.h ) 72bytes long. 73Otherwise, the user name is copied to a static buffer. 74.Sh RETURN VALUES 75If 76.Fa buf 77is not the 78.Dv NULL 79pointer, 80.Fa buf 81is returned; 82otherwise the address of the static buffer is returned. 83.Pp 84If the user name could not be determined, if 85.Fa buf 86is not the 87.Dv NULL 88pointer, the null character 89.Sq \e0 90will be stored at 91.Fa *buf ; 92otherwise 93the 94.Dv NULL 95pointer is returned. 96.Sh SEE ALSO 97.Xr getlogin 2 , 98.Xr getpwent 3 99.Sh STANDARDS 100The 101.Fn cuserid 102function conforms to 103.St -p1003.1-88 . 104.Sh BUGS 105Due to irreconcilable differences in historic implementations, 106.Fn cuserid 107was removed from the 108.St -p1003.1-90 109standard. 110This implementation exists purely for compatibility with existing programs. 111New programs should use one of the following three alternatives to 112obtain the user name: 113.Pp 114.Bl -enum -offset indent -compact 115.It 116.Fn getlogin 117to return the user's login name. 118.It 119.Nm getpwuid Ns Pq Fn geteuid 120to return the user name associated with the calling process' effective user ID. 121.It 122.Nm getpwuid Ns Pq Fn getuid 123to return the user name associated with the calling process' real user ID. 124.El 125.Pp 126The 127.Fn cuserid 128function uses 129.Fn getpwuid ; 130thus the results of a user's call to 131.Fn getpwent , 132.Fn getpwnam 133or 134.Fn getpwuid 135will be overwritten by subsequent calls to 136.Fn cuserid . 137