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 (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21
22/*
23 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
24 * Use is subject to license terms.
25 */
26
27/*	Copyright (c) 1988 AT&T	*/
28/*	  All Rights Reserved  	*/
29
30#pragma ident	"%Z%%M%	%I%	%E% SMI"
31
32#pragma weak _cuserid = cuserid
33
34#include "lint.h"
35#include <stdio.h>
36#include <pwd.h>
37#include <string.h>
38#include <stdlib.h>
39#include <unistd.h>
40#include <pthread.h>
41
42static char res[L_cuserid];
43
44char *
45cuserid(char *s)
46{
47	struct passwd *pw;
48	struct passwd pwd;
49	char buffer[BUFSIZ];
50	char utname[L_cuserid];
51	char *p;
52	int cancel_state;
53
54	/*
55	 * The UNIX98 Posix conformance test suite requires
56	 * cuserid() to not be a cancellation point.
57	 */
58	(void) pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cancel_state);
59
60	if (s == NULL)
61		s = res;
62	if ((p = getlogin_r(utname, L_cuserid)) != NULL) {
63		(void) strlcpy(s, p, L_cuserid);
64	} else if ((pw = getpwuid_r(getuid(), &pwd, buffer, BUFSIZ)) != NULL) {
65		(void) strlcpy(s, pw->pw_name, L_cuserid);
66	} else {
67		*s = '\0';
68		s = NULL;
69	}
70
71	(void) pthread_setcancelstate(cancel_state, NULL);
72	return (s);
73}
74