getlogin.c revision 1.12 
1/*	$NetBSD: getlogin.c,v 1.12 2003/08/07 16:42:50 agc Exp $	*/
2
3/*
4 * Copyright (c) 1988, 1993
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 *    may be used to endorse or promote products derived from this software
17 *    without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32#include <sys/cdefs.h>
33#if defined(LIBC_SCCS) && !defined(lint)
34#if 0
35static char sccsid[] = "@(#)getlogin.c	8.1 (Berkeley) 6/4/93";
36#else
37__RCSID("$NetBSD: getlogin.c,v 1.12 2003/08/07 16:42:50 agc Exp $");
38#endif
39#endif /* LIBC_SCCS and not lint */
40
41#include "namespace.h"
42#include <sys/param.h>
43#include <pwd.h>
44#include <utmp.h>
45#include <stdio.h>
46#include <string.h>
47#include <unistd.h>
48#include "extern.h"
49
50#ifdef __weak_alias
51__weak_alias(getlogin,_getlogin)
52__weak_alias(setlogin,_setlogin)
53#endif
54
55int	__logname_valid;		/* known to setlogin() */
56
57char *
58getlogin()
59{
60	static char logname[MAXLOGNAME + 1];
61
62	if (__logname_valid == 0) {
63		if (__getlogin(logname, sizeof(logname) - 1) < 0)
64			return ((char *)NULL);
65		__logname_valid = 1;
66	}
67	return (*logname ? logname : (char *)NULL);
68}
69
70int
71setlogin(const char *name)
72{
73	int retval;
74
75	retval = __setlogin(name);
76	__logname_valid = 0;
77
78	return (retval);
79}
80