last.c revision 1591 
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 <tzfile.h>
56#include <unistd.h>
57#include <utmp.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
74typedef struct ttytab {
75	long	logout;				/* log out time */
76	char	tty[UT_LINESIZE + 1];		/* terminal name */
77	struct ttytab	*next;			/* linked list pointer */
78} TTY;
79TTY	*ttylist;				/* head of linked list */
80
81static long	currentout,			/* current logout value */
82		maxrec;				/* records to display */
83static char	*file = _PATH_WTMP;		/* wtmp file */
84
85void	 addarg __P((int, char *));
86TTY	*addtty __P((char *));
87void	 hostconv __P((char *));
88void	 onintr __P((int));
89char	*ttyconv __P((char *));
90int	 want __P((struct utmp *, int));
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	TTY	*T;				/* tty list 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	if ((wfd = open(file, O_RDONLY, 0)) < 0 || fstat(wfd, &stb) == -1)
169		err(1, "%s", file);
170	bl = (stb.st_size + sizeof(buf) - 1) / sizeof(buf);
171
172	(void)time(&buf[0].ut_time);
173	(void)signal(SIGINT, onintr);
174	(void)signal(SIGQUIT, onintr);
175
176	while (--bl >= 0) {
177		if (lseek(wfd, (off_t)(bl * sizeof(buf)), L_SET) == -1 ||
178		    (bytes = read(wfd, buf, sizeof(buf))) == -1)
179			err(1, "%s", file);
180		for (bp = &buf[bytes / sizeof(buf[0]) - 1]; bp >= buf; --bp) {
181			/*
182			 * if the terminal line is '~', the machine stopped.
183			 * see utmp(5) for more info.
184			 */
185			if (bp->ut_line[0] == '~' && !bp->ut_line[1]) {
186				/* everybody just logged out */
187				for (T = ttylist; T; T = T->next)
188					T->logout = -bp->ut_time;
189				currentout = -bp->ut_time;
190				crmsg = strncmp(bp->ut_name, "shutdown",
191				    UT_NAMESIZE) ? "crash" : "shutdown";
192				if (want(bp, NO)) {
193					ct = ctime(&bp->ut_time);
194				printf("%-*.*s  %-*.*s %-*.*s %10.10s %5.5s \n",
195					    UT_NAMESIZE, UT_NAMESIZE,
196					    bp->ut_name, UT_LINESIZE,
197					    UT_LINESIZE, bp->ut_line,
198					    UT_HOSTSIZE, UT_HOSTSIZE,
199					    bp->ut_host, ct, ct + 11);
200					if (maxrec != -1 && !--maxrec)
201						return;
202				}
203				continue;
204			}
205			/*
206			 * if the line is '{' or '|', date got set; see
207			 * utmp(5) for more info.
208			 */
209			if ((bp->ut_line[0] == '{' || bp->ut_line[0] == '|')
210			    && !bp->ut_line[1]) {
211				if (want(bp, NO)) {
212					ct = ctime(&bp->ut_time);
213				printf("%-*.*s  %-*.*s %-*.*s %10.10s %5.5s \n",
214				    UT_NAMESIZE, UT_NAMESIZE, bp->ut_name,
215				    UT_LINESIZE, UT_LINESIZE, bp->ut_line,
216				    UT_HOSTSIZE, UT_HOSTSIZE, bp->ut_host,
217				    ct, ct + 11);
218					if (maxrec && !--maxrec)
219						return;
220				}
221				continue;
222			}
223			/* find associated tty */
224			for (T = ttylist;; T = T->next) {
225				if (!T) {
226					/* add new one */
227					T = addtty(bp->ut_line);
228					break;
229				}
230				if (!strncmp(T->tty, bp->ut_line, UT_LINESIZE))
231					break;
232			}
233			if (bp->ut_name[0] && want(bp, YES)) {
234				ct = ctime(&bp->ut_time);
235				printf("%-*.*s  %-*.*s %-*.*s %10.10s %5.5s ",
236				UT_NAMESIZE, UT_NAMESIZE, bp->ut_name,
237				UT_LINESIZE, UT_LINESIZE, bp->ut_line,
238				UT_HOSTSIZE, UT_HOSTSIZE, bp->ut_host,
239				ct, ct + 11);
240				if (!T->logout)
241					puts("  still logged in");
242				else {
243					if (T->logout < 0) {
244						T->logout = -T->logout;
245						printf("- %s", crmsg);
246					}
247					else
248						printf("- %5.5s",
249						    ctime(&T->logout)+11);
250					delta = T->logout - bp->ut_time;
251					if (delta < SECSPERDAY)
252						printf("  (%5.5s)\n",
253						    asctime(gmtime(&delta))+11);
254					else
255						printf(" (%ld+%5.5s)\n",
256						    delta / SECSPERDAY,
257						    asctime(gmtime(&delta))+11);
258				}
259				if (maxrec != -1 && !--maxrec)
260					return;
261			}
262			T->logout = bp->ut_time;
263		}
264	}
265	ct = ctime(&buf[0].ut_time);
266	printf("\nwtmp begins %10.10s %5.5s \n", ct, ct + 11);
267}
268
269/*
270 * want --
271 *	see if want this entry
272 */
273int
274want(bp, check)
275	struct utmp *bp;
276	int check;
277{
278	ARG *step;
279
280	if (check)
281		/*
282		 * when uucp and ftp log in over a network, the entry in
283		 * the utmp file is the name plus their process id.  See
284		 * etc/ftpd.c and usr.bin/uucp/uucpd.c for more information.
285		 */
286		if (!strncmp(bp->ut_line, "ftp", sizeof("ftp") - 1))
287			bp->ut_line[3] = '\0';
288		else if (!strncmp(bp->ut_line, "uucp", sizeof("uucp") - 1))
289			bp->ut_line[4] = '\0';
290	if (!arglist)
291		return (YES);
292
293	for (step = arglist; step; step = step->next)
294		switch(step->type) {
295		case HOST_TYPE:
296			if (!strncasecmp(step->name, bp->ut_host, UT_HOSTSIZE))
297				return (YES);
298			break;
299		case TTY_TYPE:
300			if (!strncmp(step->name, bp->ut_line, UT_LINESIZE))
301				return (YES);
302			break;
303		case USER_TYPE:
304			if (!strncmp(step->name, bp->ut_name, UT_NAMESIZE))
305				return (YES);
306			break;
307	}
308	return (NO);
309}
310
311/*
312 * addarg --
313 *	add an entry to a linked list of arguments
314 */
315void
316addarg(type, arg)
317	int type;
318	char *arg;
319{
320	ARG *cur;
321
322	if (!(cur = (ARG *)malloc((u_int)sizeof(ARG))))
323		err(1, "malloc failure");
324	cur->next = arglist;
325	cur->type = type;
326	cur->name = arg;
327	arglist = cur;
328}
329
330/*
331 * addtty --
332 *	add an entry to a linked list of ttys
333 */
334TTY *
335addtty(ttyname)
336	char *ttyname;
337{
338	TTY *cur;
339
340	if (!(cur = (TTY *)malloc((u_int)sizeof(TTY))))
341		err(1, "malloc failure");
342	cur->next = ttylist;
343	cur->logout = currentout;
344	memmove(cur->tty, ttyname, UT_LINESIZE);
345	return (ttylist = cur);
346}
347
348/*
349 * hostconv --
350 *	convert the hostname to search pattern; if the supplied host name
351 *	has a domain attached that is the same as the current domain, rip
352 *	off the domain suffix since that's what login(1) does.
353 */
354void
355hostconv(arg)
356	char *arg;
357{
358	static int first = 1;
359	static char *hostdot, name[MAXHOSTNAMELEN];
360	char *argdot;
361
362	if (!(argdot = strchr(arg, '.')))
363		return;
364	if (first) {
365		first = 0;
366		if (gethostname(name, sizeof(name)))
367			err(1, "gethostname");
368		hostdot = strchr(name, '.');
369	}
370	if (hostdot && !strcasecmp(hostdot, argdot))
371		*argdot = '\0';
372}
373
374/*
375 * ttyconv --
376 *	convert tty to correct name.
377 */
378char *
379ttyconv(arg)
380	char *arg;
381{
382	char *mval;
383
384	/*
385	 * kludge -- we assume that all tty's end with
386	 * a two character suffix.
387	 */
388	if (strlen(arg) == 2) {
389		/* either 6 for "ttyxx" or 8 for "console" */
390		if (!(mval = malloc((u_int)8)))
391			err(1, "malloc failure");
392		if (!strcmp(arg, "co"))
393			(void)strcpy(mval, "console");
394		else {
395			(void)strcpy(mval, "tty");
396			(void)strcpy(mval + 3, arg);
397		}
398		return (mval);
399	}
400	if (!strncmp(arg, _PATH_DEV, sizeof(_PATH_DEV) - 1))
401		return (arg + 5);
402	return (arg);
403}
404
405/*
406 * onintr --
407 *	on interrupt, we inform the user how far we've gotten
408 */
409void
410onintr(signo)
411	int signo;
412{
413	char *ct;
414
415	ct = ctime(&buf[0].ut_time);
416	printf("\ninterrupted %10.10s %5.5s \n", ct, ct + 11);
417	if (signo == SIGINT)
418		exit(1);
419	(void)fflush(stdout);			/* fix required for rsh */
420}
421