xref: /titanic_50/usr/src/lib/libbc/libc/stdio/common/cuserid.c (revision 24bb1048b1197ebc9afe761e4098573aeedfe8c9)
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 /*      Copyright (c) 1984 AT&T */
23 /*        All Rights Reserved   */
24 
25 #pragma ident	"%Z%%M%	%I%	%E% SMI"  /* from S5R2 1.3 */
26 
27 /*LINTLIBRARY*/
28 #include <stdio.h>
29 #include <pwd.h>
30 
31 extern char *strcpy(), *getlogin();
32 extern int getuid();
33 extern struct passwd *getpwuid();
34 static char res[L_cuserid];
35 
36 char *
37 cuserid(s)
38 char	*s;
39 {
40 	register struct passwd *pw;
41 	register char *p;
42 
43 	if (s == NULL)
44 		s = res;
45 	p = getlogin();
46 	if (p != NULL)
47 		return (strcpy(s, p));
48 	pw = getpwuid(getuid());
49 	endpwent();
50 	if (pw != NULL)
51 		return (strcpy(s, pw->pw_name));
52 	*s = '\0';
53 	return (NULL);
54 }
55