xref: /titanic_41/usr/src/lib/libc/port/stdio/cuserid.c (revision 7c478bd95313f5f23a4c958a745db2134aa03244)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
28 
29 /*	Copyright (c) 1988 AT&T	*/
30 /*	  All Rights Reserved  	*/
31 
32 
33 #pragma weak cuserid = _cuserid
34 
35 #include "synonyms.h"
36 #include <stdio.h>
37 #include <pwd.h>
38 #include <string.h>
39 #include <stdlib.h>
40 #include <unistd.h>
41 
42 static char res[L_cuserid];
43 
44 char *
45 cuserid(char *s)
46 {
47 	struct passwd *pw;
48 	struct passwd pwd;
49 	char buffer[BUFSIZ];
50 	char utname[L_cuserid];
51 	char *p;
52 
53 	if (s == NULL)
54 		s = res;
55 	p = getlogin_r(utname, L_cuserid);
56 	s[L_cuserid - 1] = '\0';
57 	if (p != NULL)
58 		return (strncpy(s, p, L_cuserid - 1));
59 	pw = getpwuid_r(getuid(), &pwd, buffer, BUFSIZ);
60 	if (pw != NULL)
61 		return (strncpy(s, pw->pw_name, L_cuserid - 1));
62 	*s = '\0';
63 	return (NULL);
64 }
65