xref: /netbsd/lib/libutil/logout.c (revision 961e3a84)
1 /*	$NetBSD: logout.c,v 1.14 2002/09/27 20:42:48 jdolecek 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. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *	This product includes software developed by the University of
18  *	California, Berkeley and its contributors.
19  * 4. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #include <sys/cdefs.h>
37 #if defined(LIBC_SCCS) && !defined(lint)
38 #if 0
39 static char sccsid[] = "@(#)logout.c	8.1 (Berkeley) 6/4/93";
40 #else
41 __RCSID("$NetBSD: logout.c,v 1.14 2002/09/27 20:42:48 jdolecek Exp $");
42 #endif
43 #endif /* LIBC_SCCS and not lint */
44 
45 #include <sys/types.h>
46 #include <sys/time.h>
47 
48 #include <assert.h>
49 #include <fcntl.h>
50 #include <stdlib.h>
51 #include <string.h>
52 #include <time.h>
53 #include <unistd.h>
54 #include <util.h>
55 #include <utmp.h>
56 
57 int
58 logout(const char *line)
59 {
60 	int fd, rval;
61 	struct utmp ut;
62 
63 	_DIAGASSERT(line != NULL);
64 
65 	if ((fd = open(_PATH_UTMP, O_RDWR, 0)) < 0)
66 		return(0);
67 	rval = 0;
68 	while (read(fd, &ut, sizeof(ut)) == sizeof(ut)) {
69 		if (!ut.ut_name[0] || strncmp(ut.ut_line, line, UT_LINESIZE))
70 			continue;
71 		memset(ut.ut_name, 0, UT_NAMESIZE);
72 		memset(ut.ut_host, 0, UT_HOSTSIZE);
73 		(void)time(&ut.ut_time);
74 		(void)lseek(fd, -(off_t)sizeof(ut), SEEK_CUR);
75 		(void)write(fd, &ut, sizeof(ut));
76 		rval = 1;
77 	}
78 	(void)close(fd);
79 	return(rval);
80 }
81