last.c revision 11547 
1/*
2 * Copyright (c) 1987, 1993, 1994
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 *    must display the following acknowledgement:
15 *	This product includes software developed by the University of
16 *	California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34#ifndef lint
35static char copyright[] =
36"@(#) Copyright (c) 1987, 1993, 1994\n\
37	The Regents of the University of California.  All rights reserved.\n";
38#endif /* not lint */
39
40#ifndef lint
41static char sccsid[] = "@(#)last.c	8.2 (Berkeley) 4/2/94";
42#endif /* not lint */
43
44#include <sys/param.h>
45#include <sys/stat.h>
46
47#include <err.h>
48#include <fcntl.h>
49#include <paths.h>
50#include <signal.h>
51#include <stdio.h>
52#include <stdlib.h>
53#include <string.h>
54#include <time.h>
55#include <unistd.h>
56#include <utmp.h>
57#include <sys/queue.h>
58
59#define	NO	0				/* false/no */
60#define	YES	1				/* true/yes */
61
62static struct utmp	buf[1024];		/* utmp read buffer */
63
64typedef struct arg {
65	char	*name;				/* argument */
66#define	HOST_TYPE	-2
67#define	TTY_TYPE	-3
68#define	USER_TYPE	-4
69	int	type;				/* type of arg */
70	struct arg	*next;			/* linked list pointer */
71} ARG;
72ARG	*arglist;				/* head of linked list */
73
74LIST_HEAD(ttylisthead, ttytab) ttylist;
75
76struct ttytab {
77	long	logout;				/* log out time */
78	char	tty[UT_LINESIZE + 1];		/* terminal name */
79	LIST_ENTRY(ttytab) list;
80};
81
82static long	currentout,			/* current logout value */
83		maxrec;				/* records to display */
84static char	*file = _PATH_WTMP;		/* wtmp file */
85
86void	 addarg __P((int, char *));
87void	 hostconv __P((char *));
88void	 onintr __P((int));
89char	*ttyconv __P((char *));
90int	 want __P((struct utmp *));
91void	 wtmp __P((void));
92
93int
94main(argc, argv)
95	int argc;
96	char *argv[];
97{
98	extern int optind;
99	extern char *optarg;
100	int ch;
101	char *p;
102
103	maxrec = -1;
104	while ((ch = getopt(argc, argv, "0123456789f:h:t:")) != EOF)
105		switch (ch) {
106		case '0': case '1': case '2': case '3': case '4':
107		case '5': case '6': case '7': case '8': case '9':
108			/*
109			 * kludge: last was originally designed to take
110			 * a number after a dash.
111			 */
112			if (maxrec == -1) {
113				p = argv[optind - 1];
114				if (p[0] == '-' && p[1] == ch && !p[2])
115					maxrec = atol(++p);
116				else
117					maxrec = atol(argv[optind] + 1);
118				if (!maxrec)
119					exit(0);
120			}
121			break;
122		case 'f':
123			file = optarg;
124			break;
125		case 'h':
126			hostconv(optarg);
127			addarg(HOST_TYPE, optarg);
128			break;
129		case 't':
130			addarg(TTY_TYPE, ttyconv(optarg));
131			break;
132		case '?':
133		default:
134			(void)fprintf(stderr,
135	"usage: last [-#] [-f file] [-t tty] [-h hostname] [user ...]\n");
136			exit(1);
137		}
138
139	if (argc) {
140		setlinebuf(stdout);
141		for (argv += optind; *argv; ++argv) {
142#define	COMPATIBILITY
143#ifdef	COMPATIBILITY
144			/* code to allow "last p5" to work */
145			addarg(TTY_TYPE, ttyconv(*argv));
146#endif
147			addarg(USER_TYPE, *argv);
148		}
149	}
150	wtmp();
151	exit(0);
152}
153
154/*
155 * wtmp --
156 *	read through the wtmp file
157 */
158void
159wtmp()
160{
161	struct utmp	*bp;			/* current structure */
162	struct ttytab	*tt;				/* ttylist entry */
163	struct stat	stb;			/* stat of file for size */
164	long	bl, delta;			/* time difference */
165	int	bytes, wfd;
166	char	*ct, *crmsg;
167
168	LIST_INIT(&ttylist);
169
170	if ((wfd = open(file, O_RDONLY, 0)) < 0 || fstat(wfd, &stb) == -1)
171		err(1, "%s", file);
172	bl = (stb.st_size + sizeof(buf) - 1) / sizeof(buf);
173
174	(void)time(&buf[0].ut_time);
175	(void)signal(SIGINT, onintr);
176	(void)signal(SIGQUIT, onintr);
177
178	while (--bl >= 0) {
179		if (lseek(wfd, (off_t)(bl * sizeof(buf)), L_SET) == -1 ||
180		    (bytes = read(wfd, buf, sizeof(buf))) == -1)
181			err(1, "%s", file);
182		for (bp = &buf[bytes / sizeof(buf[0]) - 1]; bp >= buf; --bp) {
183			/*
184			 * if the terminal line is '~', the machine stopped.
185			 * see utmp(5) for more info.
186			 */
187			if (bp->ut_line[0] == '~' && !bp->ut_line[1]) {
188				/* everybody just logged out */
189				for (tt = ttylist.lh_first; tt; tt = tt->list.le_next) {
190					LIST_REMOVE(tt, list);
191					free(tt);
192				}
193				currentout = -bp->ut_time;
194				crmsg = strncmp(bp->ut_name, "shutdown",
195				    UT_NAMESIZE) ? "crash" : "shutdown";
196				if (want(bp)) {
197					ct = ctime(&bp->ut_time);
198					printf("%-*.*s  %-*.*s %-*.*s %10.10s %5.5s \n",
199					    UT_NAMESIZE, UT_NAMESIZE,
200					    bp->ut_name, UT_LINESIZE,
201					    UT_LINESIZE, bp->ut_line,
202					    UT_HOSTSIZE, UT_HOSTSIZE,
203					    bp->ut_host, ct, ct + 11);
204					if (maxrec != -1 && !--maxrec)
205						return;
206				}
207				continue;
208			}
209			/*
210			 * if the line is '{' or '|', date got set; see
211			 * utmp(5) for more info.
212			 */
213			if ((bp->ut_line[0] == '{' || bp->ut_line[0] == '|')
214			    && !bp->ut_line[1]) {
215				if (want(bp)) {
216					ct = ctime(&bp->ut_time);
217					printf("%-*.*s  %-*.*s %-*.*s %10.10s %5.5s \n",
218					    UT_NAMESIZE, UT_NAMESIZE, bp->ut_name,
219					    UT_LINESIZE, UT_LINESIZE, bp->ut_line,
220					    UT_HOSTSIZE, UT_HOSTSIZE, bp->ut_host,
221					    ct, ct + 11);
222					if (maxrec && !--maxrec)
223						return;
224				}
225				continue;
226			}
227			if (bp->ut_name[0] == '\0' || want(bp)) {
228				/* find associated tty */
229				for (tt = ttylist.lh_first; ; tt = tt->list.le_next) {
230					if (tt == NULL) {
231						/* add new one */
232						tt = malloc(sizeof(struct ttytab));
233						if (tt == NULL)
234							err(1, "malloc failure");
235						tt->logout = currentout;
236						strncpy(tt->tty, bp->ut_line, UT_LINESIZE);
237						LIST_INSERT_HEAD(&ttylist, tt, list);
238						break;
239					}
240					if (!strncmp(tt->tty, bp->ut_line, UT_LINESIZE))
241						break;
242				}
243				if (bp->ut_name[0]) {
244					/*
245					 * when uucp and ftp log in over a network, the entry in
246					 * the utmp file is the name plus their process id.  See
247					 * etc/ftpd.c and usr.bin/uucp/uucpd.c for more information.
248					 */
249					if (!strncmp(bp->ut_line, "ftp", sizeof("ftp") - 1))
250						bp->ut_line[3] = '\0';
251					else if (!strncmp(bp->ut_line, "uucp", sizeof("uucp") - 1))
252						bp->ut_line[4] = '\0';
253					ct = ctime(&bp->ut_time);
254					printf("%-*.*s  %-*.*s %-*.*s %10.10s %5.5s ",
255					    UT_NAMESIZE, UT_NAMESIZE, bp->ut_name,
256					    UT_LINESIZE, UT_LINESIZE, bp->ut_line,
257					    UT_HOSTSIZE, UT_HOSTSIZE, bp->ut_host,
258					    ct, ct + 11);
259					if (!tt->logout)
260						puts("  still logged in");
261					else {
262						if (tt->logout < 0) {
263							tt->logout = -tt->logout;
264							printf("- %s", crmsg);
265						}
266						else
267							printf("- %5.5s",
268							    ctime(&tt->logout)+11);
269						delta = tt->logout - bp->ut_time;
270						if (delta < 86400)
271							printf("  (%5.5s)\n",
272							    asctime(gmtime(&delta))+11);
273						else
274							printf(" (%ld+%5.5s)\n",
275							    delta / 86400,
276							    asctime(gmtime(&delta))+11);
277					}
278					LIST_REMOVE(tt, list);
279					free(tt);
280					if (maxrec != -1 && !--maxrec)
281						return;
282				} else {
283					tt->logout = bp->ut_time;
284				}
285			}
286		}
287	}
288	ct = ctime(&buf[0].ut_time);
289	printf("\nwtmp begins %10.10s %5.5s \n", ct, ct + 11);
290}
291
292/*
293 * want --
294 *	see if want this entry
295 */
296int
297want(bp)
298	struct utmp *bp;
299{
300	ARG *step;
301
302	if (!arglist)
303		return (YES);
304
305	for (step = arglist; step; step = step->next)
306		switch(step->type) {
307		case HOST_TYPE:
308			if (!strncasecmp(step->name, bp->ut_host, UT_HOSTSIZE))
309				return (YES);
310			break;
311		case TTY_TYPE:
312			if (!strncmp(step->name, bp->ut_line, UT_LINESIZE))
313				return (YES);
314			break;
315		case USER_TYPE:
316			if (!strncmp(step->name, bp->ut_name, UT_NAMESIZE))
317				return (YES);
318			break;
319	}
320	return (NO);
321}
322
323/*
324 * addarg --
325 *	add an entry to a linked list of arguments
326 */
327void
328addarg(type, arg)
329	int type;
330	char *arg;
331{
332	ARG *cur;
333
334	if (!(cur = (ARG *)malloc((u_int)sizeof(ARG))))
335		err(1, "malloc failure");
336	cur->next = arglist;
337	cur->type = type;
338	cur->name = arg;
339	arglist = cur;
340}
341
342/*
343 * hostconv --
344 *	convert the hostname to search pattern; if the supplied host name
345 *	has a domain attached that is the same as the current domain, rip
346 *	off the domain suffix since that's what login(1) does.
347 */
348void
349hostconv(arg)
350	char *arg;
351{
352	static int first = 1;
353	static char *hostdot, name[MAXHOSTNAMELEN];
354	char *argdot;
355
356	if (!(argdot = strchr(arg, '.')))
357		return;
358	if (first) {
359		first = 0;
360		if (gethostname(name, sizeof(name)))
361			err(1, "gethostname");
362		hostdot = strchr(name, '.');
363	}
364	if (hostdot && !strcasecmp(hostdot, argdot))
365		*argdot = '\0';
366}
367
368/*
369 * ttyconv --
370 *	convert tty to correct name.
371 */
372char *
373ttyconv(arg)
374	char *arg;
375{
376	char *mval;
377
378	/*
379	 * kludge -- we assume that all tty's end with
380	 * a two character suffix.
381	 */
382	if (strlen(arg) == 2) {
383		/* either 6 for "ttyxx" or 8 for "console" */
384		if (!(mval = malloc((u_int)8)))
385			err(1, "malloc failure");
386		if (!strcmp(arg, "co"))
387			(void)strcpy(mval, "console");
388		else {
389			(void)strcpy(mval, "tty");
390			(void)strcpy(mval + 3, arg);
391		}
392		return (mval);
393	}
394	if (!strncmp(arg, _PATH_DEV, sizeof(_PATH_DEV) - 1))
395		return (arg + 5);
396	return (arg);
397}
398
399/*
400 * onintr --
401 *	on interrupt, we inform the user how far we've gotten
402 */
403void
404onintr(signo)
405	int signo;
406{
407	char *ct;
408
409	ct = ctime(&buf[0].ut_time);
410	printf("\ninterrupted %10.10s %5.5s \n", ct, ct + 11);
411	if (signo == SIGINT)
412		exit(1);
413	(void)fflush(stdout);			/* fix required for rsh */
414}
415