last.c revision 36434 
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 <locale.h>
50#include <paths.h>
51#include <signal.h>
52#include <stdio.h>
53#include <stdlib.h>
54#include <string.h>
55#include <time.h>
56#include <unistd.h>
57#include <utmp.h>
58#include <sys/queue.h>
59
60#define	NO	0				/* false/no */
61#define	YES	1				/* true/yes */
62
63static struct utmp	buf[1024];		/* utmp read buffer */
64
65typedef struct arg {
66	char	*name;				/* argument */
67#define	HOST_TYPE	-2
68#define	TTY_TYPE	-3
69#define	USER_TYPE	-4
70	int	type;				/* type of arg */
71	struct arg	*next;			/* linked list pointer */
72} ARG;
73ARG	*arglist;				/* head of linked list */
74
75LIST_HEAD(ttylisthead, ttytab) ttylist;
76
77struct ttytab {
78	time_t	logout;				/* log out time */
79	char	tty[UT_LINESIZE + 1];		/* terminal name */
80	LIST_ENTRY(ttytab) list;
81};
82
83static long	currentout,			/* current logout value */
84		maxrec;				/* records to display */
85static char	*file = _PATH_WTMP;		/* wtmp file */
86static int	sflag = 0;			/* show delta in seconds */
87static int	width = 5;			/* show seconds in delta */
88
89void	 addarg __P((int, char *));
90void	 hostconv __P((char *));
91void	 onintr __P((int));
92char	*ttyconv __P((char *));
93int	 want __P((struct utmp *));
94void	 wtmp __P((void));
95
96void
97usage(void)
98{
99	(void)fprintf(stderr,
100	"usage: last [-#] [-f file] [-h hostname] [-t tty] [-s|w] [user ...]\n");
101	exit(1);
102}
103
104int
105main(argc, argv)
106	int argc;
107	char *argv[];
108{
109	extern int optind;
110	extern char *optarg;
111	int ch;
112	char *p;
113
114	(void) setlocale(LC_TIME, "");
115
116	maxrec = -1;
117	while ((ch = getopt(argc, argv, "0123456789f:h:st:w")) != -1)
118		switch (ch) {
119		case '0': case '1': case '2': case '3': case '4':
120		case '5': case '6': case '7': case '8': case '9':
121			/*
122			 * kludge: last was originally designed to take
123			 * a number after a dash.
124			 */
125			if (maxrec == -1) {
126				p = argv[optind - 1];
127				if (p[0] == '-' && p[1] == ch && !p[2])
128					maxrec = atol(++p);
129				else
130					maxrec = atol(argv[optind] + 1);
131				if (!maxrec)
132					exit(0);
133			}
134			break;
135		case 'f':
136			file = optarg;
137			break;
138		case 'h':
139			hostconv(optarg);
140			addarg(HOST_TYPE, optarg);
141			break;
142		case 's':
143			sflag++;	/* Show delta as seconds */
144			break;
145		case 't':
146			addarg(TTY_TYPE, ttyconv(optarg));
147			break;
148		case 'w':
149			width = 8;
150			break;
151		case '?':
152		default:
153			usage();
154		}
155
156	if (sflag && width == 8) usage();
157
158	if (argc) {
159		setlinebuf(stdout);
160		for (argv += optind; *argv; ++argv) {
161#define	COMPATIBILITY
162#ifdef	COMPATIBILITY
163			/* code to allow "last p5" to work */
164			addarg(TTY_TYPE, ttyconv(*argv));
165#endif
166			addarg(USER_TYPE, *argv);
167		}
168	}
169	wtmp();
170	exit(0);
171}
172
173/*
174 * wtmp --
175 *	read through the wtmp file
176 */
177void
178wtmp()
179{
180	struct utmp	*bp;			/* current structure */
181	struct ttytab	*tt, *ttx;		/* ttylist entry */
182	struct stat	stb;			/* stat of file for size */
183	long	bl;
184	time_t	delta;				/* time difference */
185	int	bytes, wfd;
186	char    *crmsg;
187	char ct[80];
188	struct tm *tm;
189
190	LIST_INIT(&ttylist);
191
192	if ((wfd = open(file, O_RDONLY, 0)) < 0 || fstat(wfd, &stb) == -1)
193		err(1, "%s", file);
194	bl = (stb.st_size + sizeof(buf) - 1) / sizeof(buf);
195
196	(void)time(&buf[0].ut_time);
197	(void)signal(SIGINT, onintr);
198	(void)signal(SIGQUIT, onintr);
199
200	while (--bl >= 0) {
201		if (lseek(wfd, (off_t)(bl * sizeof(buf)), L_SET) == -1 ||
202		    (bytes = read(wfd, buf, sizeof(buf))) == -1)
203			err(1, "%s", file);
204		for (bp = &buf[bytes / sizeof(buf[0]) - 1]; bp >= buf; --bp) {
205			/*
206			 * if the terminal line is '~', the machine stopped.
207			 * see utmp(5) for more info.
208			 */
209			if (bp->ut_line[0] == '~' && !bp->ut_line[1]) {
210				/* everybody just logged out */
211				for (tt = ttylist.lh_first; tt;) {
212					LIST_REMOVE(tt, list);
213					ttx = tt;
214					tt = tt->list.le_next;
215					free(ttx);
216				}
217				currentout = -bp->ut_time;
218				crmsg = strncmp(bp->ut_name, "shutdown",
219				    UT_NAMESIZE) ? "crash" : "shutdown";
220				if (want(bp)) {
221					tm = localtime(&bp->ut_time);
222					(void) strftime(ct, sizeof(ct), "%c", tm);
223					printf("%-*.*s %-*.*s %-*.*s %10.10s %5.5s \n",
224					    UT_NAMESIZE, UT_NAMESIZE,
225					    bp->ut_name, UT_LINESIZE,
226					    UT_LINESIZE, bp->ut_line,
227					    UT_HOSTSIZE, UT_HOSTSIZE,
228					    bp->ut_host, ct, ct + 11);
229					if (maxrec != -1 && !--maxrec)
230						return;
231				}
232				continue;
233			}
234			/*
235			 * if the line is '{' or '|', date got set; see
236			 * utmp(5) for more info.
237			 */
238			if ((bp->ut_line[0] == '{' || bp->ut_line[0] == '|')
239			    && !bp->ut_line[1]) {
240				if (want(bp)) {
241					tm = localtime(&bp->ut_time);
242					(void) strftime(ct, sizeof(ct), "%c", tm);
243					printf("%-*.*s %-*.*s %-*.*s %10.10s %5.5s \n",
244					    UT_NAMESIZE, UT_NAMESIZE, bp->ut_name,
245					    UT_LINESIZE, UT_LINESIZE, bp->ut_line,
246					    UT_HOSTSIZE, UT_HOSTSIZE, bp->ut_host,
247					    ct, ct + 11);
248					if (maxrec && !--maxrec)
249						return;
250				}
251				continue;
252			}
253			if (bp->ut_name[0] == '\0' || want(bp)) {
254				/* find associated tty */
255				for (tt = ttylist.lh_first; ; tt = tt->list.le_next) {
256					if (tt == NULL) {
257						/* add new one */
258						tt = malloc(sizeof(struct ttytab));
259						if (tt == NULL)
260							err(1, "malloc failure");
261						tt->logout = currentout;
262						strncpy(tt->tty, bp->ut_line, UT_LINESIZE);
263						LIST_INSERT_HEAD(&ttylist, tt, list);
264						break;
265					}
266					if (!strncmp(tt->tty, bp->ut_line, UT_LINESIZE))
267						break;
268				}
269				if (bp->ut_name[0]) {
270					/*
271					 * when uucp and ftp log in over a network, the entry in
272					 * the utmp file is the name plus their process id.  See
273					 * etc/ftpd.c and usr.bin/uucp/uucpd.c for more information.
274					 */
275					if (!strncmp(bp->ut_line, "ftp", sizeof("ftp") - 1))
276						bp->ut_line[3] = '\0';
277					else if (!strncmp(bp->ut_line, "uucp", sizeof("uucp") - 1))
278						bp->ut_line[4] = '\0';
279					tm = localtime(&bp->ut_time);
280					(void) strftime(ct, sizeof(ct), "%c", tm);
281					printf("%-*.*s %-*.*s %-*.*s %10.10s %5.5s ",
282					    UT_NAMESIZE, UT_NAMESIZE, bp->ut_name,
283					    UT_LINESIZE, UT_LINESIZE, bp->ut_line,
284					    UT_HOSTSIZE, UT_HOSTSIZE, bp->ut_host,
285					    ct, ct + 11);
286					if (!tt->logout)
287						puts("  still logged in");
288					else {
289						if (tt->logout < 0) {
290							tt->logout = -tt->logout;
291							printf("- %s", crmsg);
292						}
293						else {
294							tm = localtime(&tt->logout);
295							(void) strftime(ct, sizeof(ct), "%c", tm);
296							printf("- %5.5s", ct + 11);
297						}
298						delta = tt->logout - bp->ut_time;
299						if ( sflag ) {
300							printf("  (%8lu)\n",
301								delta);
302						} else {
303						    tm = gmtime(&delta);
304						    (void) strftime(ct, sizeof(ct), "%c", tm);
305						    if (delta < 86400)
306							printf("  (%*.*s)\n", width, width, ct + 11);
307						    else
308							printf(" (%ld+%*.*s)\n",
309							    delta / 86400, width, width, ct + 11);
310						}
311					}
312					LIST_REMOVE(tt, list);
313					free(tt);
314					if (maxrec != -1 && !--maxrec)
315						return;
316				} else {
317					tt->logout = bp->ut_time;
318				}
319			}
320		}
321	}
322	tm = localtime(&buf[0].ut_time);
323	(void) strftime(ct, sizeof(ct), "\nwtmp begins %c\n", tm);
324	printf(ct);
325}
326
327/*
328 * want --
329 *	see if want this entry
330 */
331int
332want(bp)
333	struct utmp *bp;
334{
335	ARG *step;
336
337	if (!arglist)
338		return (YES);
339
340	for (step = arglist; step; step = step->next)
341		switch(step->type) {
342		case HOST_TYPE:
343			if (!strncasecmp(step->name, bp->ut_host, UT_HOSTSIZE))
344				return (YES);
345			break;
346		case TTY_TYPE:
347			if (!strncmp(step->name, bp->ut_line, UT_LINESIZE))
348				return (YES);
349			break;
350		case USER_TYPE:
351			if (!strncmp(step->name, bp->ut_name, UT_NAMESIZE))
352				return (YES);
353			break;
354	}
355	return (NO);
356}
357
358/*
359 * addarg --
360 *	add an entry to a linked list of arguments
361 */
362void
363addarg(type, arg)
364	int type;
365	char *arg;
366{
367	ARG *cur;
368
369	if (!(cur = (ARG *)malloc((u_int)sizeof(ARG))))
370		err(1, "malloc failure");
371	cur->next = arglist;
372	cur->type = type;
373	cur->name = arg;
374	arglist = cur;
375}
376
377/*
378 * hostconv --
379 *	convert the hostname to search pattern; if the supplied host name
380 *	has a domain attached that is the same as the current domain, rip
381 *	off the domain suffix since that's what login(1) does.
382 */
383void
384hostconv(arg)
385	char *arg;
386{
387	static int first = 1;
388	static char *hostdot, name[MAXHOSTNAMELEN];
389	char *argdot;
390
391	if (!(argdot = strchr(arg, '.')))
392		return;
393	if (first) {
394		first = 0;
395		if (gethostname(name, sizeof(name)))
396			err(1, "gethostname");
397		hostdot = strchr(name, '.');
398	}
399	if (hostdot && !strcasecmp(hostdot, argdot))
400		*argdot = '\0';
401}
402
403/*
404 * ttyconv --
405 *	convert tty to correct name.
406 */
407char *
408ttyconv(arg)
409	char *arg;
410{
411	char *mval;
412
413	/*
414	 * kludge -- we assume that all tty's end with
415	 * a two character suffix.
416	 */
417	if (strlen(arg) == 2) {
418		/* either 6 for "ttyxx" or 8 for "console" */
419		if (!(mval = malloc((u_int)8)))
420			err(1, "malloc failure");
421		if (!strcmp(arg, "co"))
422			(void)strcpy(mval, "console");
423		else {
424			(void)strcpy(mval, "tty");
425			(void)strcpy(mval + 3, arg);
426		}
427		return (mval);
428	}
429	if (!strncmp(arg, _PATH_DEV, sizeof(_PATH_DEV) - 1))
430		return (arg + 5);
431	return (arg);
432}
433
434/*
435 * onintr --
436 *	on interrupt, we inform the user how far we've gotten
437 */
438void
439onintr(signo)
440	int signo;
441{
442	char ct[80];
443	struct tm *tm;
444
445	tm = localtime(&buf[0].ut_time);
446	(void) strftime(ct, sizeof(ct), "%c", tm);
447	printf("\ninterrupted %10.10s %5.5s \n", ct, ct + 11);
448	if (signo == SIGINT)
449		exit(1);
450	(void)fflush(stdout);			/* fix required for rsh */
451}
452