last.c revision 35658 
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	long	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 */
86
87void	 addarg __P((int, char *));
88void	 hostconv __P((char *));
89void	 onintr __P((int));
90char	*ttyconv __P((char *));
91int	 want __P((struct utmp *));
92void	 wtmp __P((void));
93
94int
95main(argc, argv)
96	int argc;
97	char *argv[];
98{
99	extern int optind;
100	extern char *optarg;
101	int ch;
102	char *p;
103
104	(void) setlocale(LC_TIME, "");
105
106	maxrec = -1;
107	while ((ch = getopt(argc, argv, "0123456789f:h:t:")) != -1)
108		switch (ch) {
109		case '0': case '1': case '2': case '3': case '4':
110		case '5': case '6': case '7': case '8': case '9':
111			/*
112			 * kludge: last was originally designed to take
113			 * a number after a dash.
114			 */
115			if (maxrec == -1) {
116				p = argv[optind - 1];
117				if (p[0] == '-' && p[1] == ch && !p[2])
118					maxrec = atol(++p);
119				else
120					maxrec = atol(argv[optind] + 1);
121				if (!maxrec)
122					exit(0);
123			}
124			break;
125		case 'f':
126			file = optarg;
127			break;
128		case 'h':
129			hostconv(optarg);
130			addarg(HOST_TYPE, optarg);
131			break;
132		case 't':
133			addarg(TTY_TYPE, ttyconv(optarg));
134			break;
135		case '?':
136		default:
137			(void)fprintf(stderr,
138	"usage: last [-#] [-f file] [-t tty] [-h hostname] [user ...]\n");
139			exit(1);
140		}
141
142	if (argc) {
143		setlinebuf(stdout);
144		for (argv += optind; *argv; ++argv) {
145#define	COMPATIBILITY
146#ifdef	COMPATIBILITY
147			/* code to allow "last p5" to work */
148			addarg(TTY_TYPE, ttyconv(*argv));
149#endif
150			addarg(USER_TYPE, *argv);
151		}
152	}
153	wtmp();
154	exit(0);
155}
156
157/*
158 * wtmp --
159 *	read through the wtmp file
160 */
161void
162wtmp()
163{
164	struct utmp	*bp;			/* current structure */
165	struct ttytab	*tt, *ttx;		/* ttylist entry */
166	struct stat	stb;			/* stat of file for size */
167	long	bl, delta;			/* time difference */
168	int	bytes, wfd;
169	char    *crmsg;
170	char ct[80];
171	struct tm *tm;
172
173	LIST_INIT(&ttylist);
174
175	if ((wfd = open(file, O_RDONLY, 0)) < 0 || fstat(wfd, &stb) == -1)
176		err(1, "%s", file);
177	bl = (stb.st_size + sizeof(buf) - 1) / sizeof(buf);
178
179	(void)time(&buf[0].ut_time);
180	(void)signal(SIGINT, onintr);
181	(void)signal(SIGQUIT, onintr);
182
183	while (--bl >= 0) {
184		if (lseek(wfd, (off_t)(bl * sizeof(buf)), L_SET) == -1 ||
185		    (bytes = read(wfd, buf, sizeof(buf))) == -1)
186			err(1, "%s", file);
187		for (bp = &buf[bytes / sizeof(buf[0]) - 1]; bp >= buf; --bp) {
188			/*
189			 * if the terminal line is '~', the machine stopped.
190			 * see utmp(5) for more info.
191			 */
192			if (bp->ut_line[0] == '~' && !bp->ut_line[1]) {
193				/* everybody just logged out */
194				for (tt = ttylist.lh_first; tt;) {
195					LIST_REMOVE(tt, list);
196					ttx = tt;
197					tt = tt->list.le_next;
198					free(ttx);
199				}
200				currentout = -bp->ut_time;
201				crmsg = strncmp(bp->ut_name, "shutdown",
202				    UT_NAMESIZE) ? "crash" : "shutdown";
203				if (want(bp)) {
204					tm = localtime(&bp->ut_time);
205					(void) strftime(ct, sizeof(ct), "%c", tm);
206					printf("%-*.*s %-*.*s %-*.*s %10.10s %5.5s \n",
207					    UT_NAMESIZE, UT_NAMESIZE,
208					    bp->ut_name, UT_LINESIZE,
209					    UT_LINESIZE, bp->ut_line,
210					    UT_HOSTSIZE, UT_HOSTSIZE,
211					    bp->ut_host, ct, ct + 11);
212					if (maxrec != -1 && !--maxrec)
213						return;
214				}
215				continue;
216			}
217			/*
218			 * if the line is '{' or '|', date got set; see
219			 * utmp(5) for more info.
220			 */
221			if ((bp->ut_line[0] == '{' || bp->ut_line[0] == '|')
222			    && !bp->ut_line[1]) {
223				if (want(bp)) {
224					tm = localtime(&bp->ut_time);
225					(void) strftime(ct, sizeof(ct), "%c", tm);
226					printf("%-*.*s %-*.*s %-*.*s %10.10s %5.5s \n",
227					    UT_NAMESIZE, UT_NAMESIZE, bp->ut_name,
228					    UT_LINESIZE, UT_LINESIZE, bp->ut_line,
229					    UT_HOSTSIZE, UT_HOSTSIZE, bp->ut_host,
230					    ct, ct + 11);
231					if (maxrec && !--maxrec)
232						return;
233				}
234				continue;
235			}
236			if (bp->ut_name[0] == '\0' || want(bp)) {
237				/* find associated tty */
238				for (tt = ttylist.lh_first; ; tt = tt->list.le_next) {
239					if (tt == NULL) {
240						/* add new one */
241						tt = malloc(sizeof(struct ttytab));
242						if (tt == NULL)
243							err(1, "malloc failure");
244						tt->logout = currentout;
245						strncpy(tt->tty, bp->ut_line, UT_LINESIZE);
246						LIST_INSERT_HEAD(&ttylist, tt, list);
247						break;
248					}
249					if (!strncmp(tt->tty, bp->ut_line, UT_LINESIZE))
250						break;
251				}
252				if (bp->ut_name[0]) {
253					/*
254					 * when uucp and ftp log in over a network, the entry in
255					 * the utmp file is the name plus their process id.  See
256					 * etc/ftpd.c and usr.bin/uucp/uucpd.c for more information.
257					 */
258					if (!strncmp(bp->ut_line, "ftp", sizeof("ftp") - 1))
259						bp->ut_line[3] = '\0';
260					else if (!strncmp(bp->ut_line, "uucp", sizeof("uucp") - 1))
261						bp->ut_line[4] = '\0';
262					tm = localtime(&bp->ut_time);
263					(void) strftime(ct, sizeof(ct), "%c", tm);
264					printf("%-*.*s %-*.*s %-*.*s %10.10s %5.5s ",
265					    UT_NAMESIZE, UT_NAMESIZE, bp->ut_name,
266					    UT_LINESIZE, UT_LINESIZE, bp->ut_line,
267					    UT_HOSTSIZE, UT_HOSTSIZE, bp->ut_host,
268					    ct, ct + 11);
269					if (!tt->logout)
270						puts("  still logged in");
271					else {
272						if (tt->logout < 0) {
273							tt->logout = -tt->logout;
274							printf("- %s", crmsg);
275						}
276						else {
277							tm = localtime(&tt->logout);
278							(void) strftime(ct, sizeof(ct), "%c", tm);
279							printf("- %5.5s", ct + 11);
280						}
281						delta = tt->logout - bp->ut_time;
282						tm = gmtime(&delta);
283						(void) strftime(ct, sizeof(ct), "%c", tm);
284						if (delta < 86400)
285							printf("  (%5.5s)\n", ct + 11);
286						else
287							printf(" (%ld+%5.5s)\n",
288							    delta / 86400, ct + 11);
289					}
290					LIST_REMOVE(tt, list);
291					free(tt);
292					if (maxrec != -1 && !--maxrec)
293						return;
294				} else {
295					tt->logout = bp->ut_time;
296				}
297			}
298		}
299	}
300	tm = localtime(&buf[0].ut_time);
301	(void) strftime(ct, sizeof(ct), "\nwtmp begins %c\n", tm);
302	printf(ct);
303}
304
305/*
306 * want --
307 *	see if want this entry
308 */
309int
310want(bp)
311	struct utmp *bp;
312{
313	ARG *step;
314
315	if (!arglist)
316		return (YES);
317
318	for (step = arglist; step; step = step->next)
319		switch(step->type) {
320		case HOST_TYPE:
321			if (!strncasecmp(step->name, bp->ut_host, UT_HOSTSIZE))
322				return (YES);
323			break;
324		case TTY_TYPE:
325			if (!strncmp(step->name, bp->ut_line, UT_LINESIZE))
326				return (YES);
327			break;
328		case USER_TYPE:
329			if (!strncmp(step->name, bp->ut_name, UT_NAMESIZE))
330				return (YES);
331			break;
332	}
333	return (NO);
334}
335
336/*
337 * addarg --
338 *	add an entry to a linked list of arguments
339 */
340void
341addarg(type, arg)
342	int type;
343	char *arg;
344{
345	ARG *cur;
346
347	if (!(cur = (ARG *)malloc((u_int)sizeof(ARG))))
348		err(1, "malloc failure");
349	cur->next = arglist;
350	cur->type = type;
351	cur->name = arg;
352	arglist = cur;
353}
354
355/*
356 * hostconv --
357 *	convert the hostname to search pattern; if the supplied host name
358 *	has a domain attached that is the same as the current domain, rip
359 *	off the domain suffix since that's what login(1) does.
360 */
361void
362hostconv(arg)
363	char *arg;
364{
365	static int first = 1;
366	static char *hostdot, name[MAXHOSTNAMELEN];
367	char *argdot;
368
369	if (!(argdot = strchr(arg, '.')))
370		return;
371	if (first) {
372		first = 0;
373		if (gethostname(name, sizeof(name)))
374			err(1, "gethostname");
375		hostdot = strchr(name, '.');
376	}
377	if (hostdot && !strcasecmp(hostdot, argdot))
378		*argdot = '\0';
379}
380
381/*
382 * ttyconv --
383 *	convert tty to correct name.
384 */
385char *
386ttyconv(arg)
387	char *arg;
388{
389	char *mval;
390
391	/*
392	 * kludge -- we assume that all tty's end with
393	 * a two character suffix.
394	 */
395	if (strlen(arg) == 2) {
396		/* either 6 for "ttyxx" or 8 for "console" */
397		if (!(mval = malloc((u_int)8)))
398			err(1, "malloc failure");
399		if (!strcmp(arg, "co"))
400			(void)strcpy(mval, "console");
401		else {
402			(void)strcpy(mval, "tty");
403			(void)strcpy(mval + 3, arg);
404		}
405		return (mval);
406	}
407	if (!strncmp(arg, _PATH_DEV, sizeof(_PATH_DEV) - 1))
408		return (arg + 5);
409	return (arg);
410}
411
412/*
413 * onintr --
414 *	on interrupt, we inform the user how far we've gotten
415 */
416void
417onintr(signo)
418	int signo;
419{
420	char ct[80];
421	struct tm *tm;
422
423	tm = localtime(&buf[0].ut_time);
424	(void) strftime(ct, sizeof(ct), "%c", tm);
425	printf("\ninterrupted %10.10s %5.5s \n", ct, ct + 11);
426	if (signo == SIGINT)
427		exit(1);
428	(void)fflush(stdout);			/* fix required for rsh */
429}
430