lastlogin.c revision 68723 
1/* $FreeBSD: head/usr.sbin/lastlogin/lastlogin.c 68723 2000-11-14 17:49:38Z ru $ */
2/*	$NetBSD: lastlogin.c,v 1.4 1998/02/03 04:45:35 perry Exp $	*/
3/*
4 * Copyright (c) 1996 John M. Vinopal
5 * 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 for the NetBSD Project
18 *	by John M. Vinopal.
19 * 4. The name of the author may not be used to endorse or promote products
20 *    derived from this software without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
23 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
24 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
25 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
26 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
27 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
28 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
29 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
30 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 */
34
35#include <sys/cdefs.h>
36#ifndef lint
37__RCSID("$FreeBSD: head/usr.sbin/lastlogin/lastlogin.c 68723 2000-11-14 17:49:38Z ru $");
38__RCSID("$NetBSD: lastlogin.c,v 1.4 1998/02/03 04:45:35 perry Exp $");
39#endif
40
41#include <sys/types.h>
42#include <err.h>
43#include <errno.h>
44#include <pwd.h>
45#include <stdio.h>
46#include <stdlib.h>
47#include <time.h>
48#include <utmp.h>
49#include <unistd.h>
50
51extern	char *__progname;
52static	const char *logfile = _PATH_LASTLOG;
53
54	int	main __P((int, char **));
55static	void	output __P((struct passwd *, struct lastlog *));
56static	void	usage __P((void));
57
58int
59main(argc, argv)
60	int argc;
61	char *argv[];
62{
63	int	ch, i;
64	FILE	*fp;
65	struct passwd	*passwd;
66	struct lastlog	last;
67
68	while ((ch = getopt(argc, argv, "")) != -1) {
69		usage();
70	}
71
72	fp = fopen(logfile, "r");
73	if (fp == NULL)
74		err(1, "%s", logfile);
75
76	setpassent(1);	/* Keep passwd file pointers open */
77
78	/* Process usernames given on the command line. */
79	if (argc > 1) {
80		long offset;
81		for (i = 1; i < argc; ++i) {
82			if ((passwd = getpwnam(argv[i])) == NULL) {
83				warnx("user '%s' not found", argv[i]);
84				continue;
85			}
86			/* Calculate the offset into the lastlog file. */
87			offset = (long)(passwd->pw_uid * sizeof(last));
88			if (fseek(fp, offset, SEEK_SET)) {
89				warn("fseek error");
90				continue;
91			}
92			if (fread(&last, sizeof(last), 1, fp) != 1) {
93				warnx("fread error on '%s'", passwd->pw_name);
94				clearerr(fp);
95				continue;
96			}
97			output(passwd, &last);
98		}
99	}
100	/* Read all lastlog entries, looking for active ones */
101	else {
102		for (i = 0; fread(&last, sizeof(last), 1, fp) == 1; i++) {
103			if (last.ll_time == 0)
104				continue;
105			if ((passwd = getpwuid((uid_t)i)) != NULL)
106				output(passwd, &last);
107		}
108		if (ferror(fp))
109			warnx("fread error");
110	}
111
112	setpassent(0);	/* Close passwd file pointers */
113
114	fclose(fp);
115	exit(0);
116}
117
118/* Duplicate the output of last(1) */
119static void
120output(p, l)
121	struct passwd *p;
122	struct lastlog *l;
123{
124	printf("%-*.*s  %-*.*s %-*.*s   %s",
125		UT_NAMESIZE, UT_NAMESIZE, p->pw_name,
126		UT_LINESIZE, UT_LINESIZE, l->ll_line,
127		UT_HOSTSIZE, UT_HOSTSIZE, l->ll_host,
128		(l->ll_time) ? ctime(&(l->ll_time)) : "Never logged in\n");
129}
130
131static void
132usage()
133{
134	fprintf(stderr, "usage: %s [user ...]\n", __progname);
135	exit(1);
136}
137