xref: /netbsd/usr.bin/last/last.c (revision bf9ec67e) 
1 /*	$NetBSD: last.c,v 1.15 2000/06/30 06:19:58 simonb Exp $	*/
2 
3 /*
4  * Copyright (c) 1987, 1993, 1994
5  *	The Regents of the University of California.  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 by the University of
18  *	California, Berkeley and its contributors.
19  * 4. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #include <sys/cdefs.h>
37 #ifndef lint
38 __COPYRIGHT(
39 "@(#) Copyright (c) 1987, 1993, 1994\n\
40 	The Regents of the University of California.  All rights reserved.\n");
41 #endif /* not lint */
42 
43 #ifndef lint
44 #if 0
45 static char sccsid[] = "@(#)last.c	8.2 (Berkeley) 4/2/94";
46 #endif
47 __RCSID("$NetBSD: last.c,v 1.15 2000/06/30 06:19:58 simonb Exp $");
48 #endif /* not lint */
49 
50 #include <sys/param.h>
51 #include <sys/stat.h>
52 
53 #include <err.h>
54 #include <fcntl.h>
55 #include <paths.h>
56 #include <signal.h>
57 #include <stdio.h>
58 #include <stdlib.h>
59 #include <string.h>
60 #include <time.h>
61 #include <tzfile.h>
62 #include <unistd.h>
63 #include <utmp.h>
64 
65 #define	NO	0			/* false/no */
66 #define	YES	1			/* true/yes */
67 
68 #define	TBUFLEN	30			/* length of time string buffer */
69 #define	TFMT	"%a %b %d %R"		/* strftime format string */
70 #define	LTFMT	"%a %b %d %Y %T"	/* strftime long format string */
71 #define	TFMTS	"%R"			/* strftime format string - time only */
72 #define	LTFMTS	"%T"			/* strftime long format string - " */
73 
74 /* fmttime() flags */
75 #define	FULLTIME	0x1		/* show year, seconds */
76 #define	TIMEONLY	0x2		/* show time only, not date */
77 #define	GMT		0x4		/* show time at GMT, for offsets only */
78 
79 static struct utmp	buf[1024];	/* utmp read buffer */
80 
81 typedef struct arg {
82 	char	*name;			/* argument */
83 #define	HOST_TYPE	-2
84 #define	TTY_TYPE	-3
85 #define	USER_TYPE	-4
86 	int	type;			/* type of arg */
87 	struct arg	*next;		/* linked list pointer */
88 } ARG;
89 ARG	*arglist;			/* head of linked list */
90 
91 typedef struct ttytab {
92 	time_t	logout;			/* log out time */
93 	char	tty[UT_LINESIZE + 1];	/* terminal name */
94 	struct ttytab	*next;		/* linked list pointer */
95 } TTY;
96 TTY	*ttylist;			/* head of linked list */
97 
98 static time_t	currentout;		/* current logout value */
99 static long	maxrec;			/* records to display */
100 static char	*file = _PATH_WTMP;	/* wtmp file */
101 static int	fulltime = 0;		/* Display seconds? */
102 
103 int	 main __P((int, char *[]));
104 void	 addarg __P((int, char *));
105 TTY	*addtty __P((char *));
106 void	 hostconv __P((char *));
107 void	 onintr __P((int));
108 char	*ttyconv __P((char *));
109 int	 want __P((struct utmp *, int));
110 void	 wtmp __P((void));
111 char	*fmttime __P((time_t, int));
112 
113 int
114 main(argc, argv)
115 	int argc;
116 	char *argv[];
117 {
118 	int ch;
119 	char *p;
120 
121 	maxrec = -1;
122 	while ((ch = getopt(argc, argv, "0123456789f:h:t:T")) != -1)
123 		switch (ch) {
124 		case '0': case '1': case '2': case '3': case '4':
125 		case '5': case '6': case '7': case '8': case '9':
126 			/*
127 			 * kludge: last was originally designed to take
128 			 * a number after a dash.
129 			 */
130 			if (maxrec == -1) {
131 				p = argv[optind - 1];
132 				if (p[0] == '-' && p[1] == ch && !p[2])
133 					maxrec = atol(++p);
134 				else
135 					maxrec = atol(argv[optind] + 1);
136 				if (!maxrec)
137 					exit(0);
138 			}
139 			break;
140 		case 'f':
141 			file = optarg;
142 			break;
143 		case 'h':
144 			hostconv(optarg);
145 			addarg(HOST_TYPE, optarg);
146 			break;
147 		case 't':
148 			addarg(TTY_TYPE, ttyconv(optarg));
149 			break;
150 		case 'T':
151 			fulltime = 1;
152 			break;
153 		case '?':
154 		default:
155 			(void)fprintf(stderr,
156 	"usage: last [-#] [-f file] [-t tty] [-h hostname] [-T] [user ...]\n");
157 			exit(1);
158 		}
159 
160 	if (argc) {
161 		setlinebuf(stdout);
162 		for (argv += optind; *argv; ++argv) {
163 #define	COMPATIBILITY
164 #ifdef	COMPATIBILITY
165 			/* code to allow "last p5" to work */
166 			addarg(TTY_TYPE, ttyconv(*argv));
167 #endif
168 			addarg(USER_TYPE, *argv);
169 		}
170 	}
171 	wtmp();
172 	exit(0);
173 }
174 
175 /*
176  * wtmp --
177  *	read through the wtmp file
178  */
179 void
180 wtmp()
181 {
182 	struct utmp	*bp;		/* current structure */
183 	TTY	*T;			/* tty list entry */
184 	struct stat	stb;		/* stat of file for size */
185 	time_t	delta;			/* time difference */
186 	off_t	bl;
187 	int	bytes, wfd;
188 	char	*ct, *crmsg;
189 
190 	crmsg = NULL;
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, bl * sizeof(buf), SEEK_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 (T = ttylist; T; T = T->next)
212 					T->logout = -bp->ut_time;
213 				currentout = -bp->ut_time;
214 				crmsg = strncmp(bp->ut_name, "shutdown",
215 				    UT_NAMESIZE) ? "crash" : "shutdown";
216 				if (want(bp, NO)) {
217 					ct = fmttime(bp->ut_time, fulltime);
218 				printf("%-*.*s  %-*.*s %-*.*s %s\n",
219 					    (int)UT_NAMESIZE, (int)UT_NAMESIZE,
220 					    bp->ut_name, (int)UT_LINESIZE,
221 					    (int)UT_LINESIZE, bp->ut_line,
222 					    (int)UT_HOSTSIZE, (int)UT_HOSTSIZE,
223 					    bp->ut_host, ct);
224 					if (maxrec != -1 && !--maxrec)
225 						return;
226 				}
227 				continue;
228 			}
229 			/*
230 			 * if the line is '{' or '|', date got set; see
231 			 * utmp(5) for more info.
232 			 */
233 			if ((bp->ut_line[0] == '{' || bp->ut_line[0] == '|')
234 			    && !bp->ut_line[1]) {
235 				if (want(bp, NO)) {
236 					ct = fmttime(bp->ut_time, fulltime);
237 				printf("%-*.*s  %-*.*s %-*.*s %s\n",
238 				    (int)UT_NAMESIZE, (int)UT_NAMESIZE,
239 				    bp->ut_name,
240 				    (int)UT_LINESIZE, (int)UT_LINESIZE,
241 				    bp->ut_line,
242 				    (int)UT_HOSTSIZE, (int)UT_HOSTSIZE,
243 				    bp->ut_host,
244 				    ct);
245 					if (maxrec && !--maxrec)
246 						return;
247 				}
248 				continue;
249 			}
250 			/* find associated tty */
251 			for (T = ttylist;; T = T->next) {
252 				if (!T) {
253 					/* add new one */
254 					T = addtty(bp->ut_line);
255 					break;
256 				}
257 				if (!strncmp(T->tty, bp->ut_line, UT_LINESIZE))
258 					break;
259 			}
260 			if (bp->ut_name[0] && want(bp, YES)) {
261 				ct = fmttime(bp->ut_time, fulltime);
262 				printf("%-*.*s  %-*.*s %-*.*s %s ",
263 				(int)UT_NAMESIZE, (int)UT_NAMESIZE, bp->ut_name,
264 				(int)UT_LINESIZE, (int)UT_LINESIZE, bp->ut_line,
265 				(int)UT_HOSTSIZE, (int)UT_HOSTSIZE, bp->ut_host,
266 				ct);
267 				if (!T->logout)
268 					puts("  still logged in");
269 				else {
270 					if (T->logout < 0) {
271 						T->logout = -T->logout;
272 						printf("- %s", crmsg);
273 					}
274 					else
275 						printf("- %s",
276 						    fmttime(T->logout,
277 						    fulltime | TIMEONLY));
278 					delta = T->logout - bp->ut_time;
279 					if (delta < SECSPERDAY)
280 						printf("  (%s)\n",
281 						    fmttime(delta,
282 						    fulltime | TIMEONLY | GMT));
283 					else
284 						printf(" (%ld+%s)\n",
285 						    delta / SECSPERDAY,
286 						    fmttime(delta,
287 						    fulltime | TIMEONLY | GMT));
288 				}
289 				if (maxrec != -1 && !--maxrec)
290 					return;
291 			}
292 			T->logout = bp->ut_time;
293 		}
294 	}
295 	fulltime = 1;	/* show full time */
296 	ct = fmttime(buf[0].ut_time, FULLTIME);
297 	printf("\nwtmp begins %s\n", ct);
298 }
299 
300 /*
301  * want --
302  *	see if want this entry
303  */
304 int
305 want(bp, check)
306 	struct utmp *bp;
307 	int check;
308 {
309 	ARG *step;
310 
311 	if (check) {
312 		/*
313 		 * when uucp and ftp log in over a network, the entry in
314 		 * the utmp file is the name plus their process id.  See
315 		 * etc/ftpd.c and usr.bin/uucp/uucpd.c for more information.
316 		 */
317 		if (!strncmp(bp->ut_line, "ftp", sizeof("ftp") - 1))
318 			bp->ut_line[3] = '\0';
319 		else if (!strncmp(bp->ut_line, "uucp", sizeof("uucp") - 1))
320 			bp->ut_line[4] = '\0';
321 	}
322 	if (!arglist)
323 		return (YES);
324 
325 	for (step = arglist; step; step = step->next)
326 		switch(step->type) {
327 		case HOST_TYPE:
328 			if (!strncasecmp(step->name, bp->ut_host, UT_HOSTSIZE))
329 				return (YES);
330 			break;
331 		case TTY_TYPE:
332 			if (!strncmp(step->name, bp->ut_line, UT_LINESIZE))
333 				return (YES);
334 			break;
335 		case USER_TYPE:
336 			if (!strncmp(step->name, bp->ut_name, UT_NAMESIZE))
337 				return (YES);
338 			break;
339 	}
340 	return (NO);
341 }
342 
343 /*
344  * addarg --
345  *	add an entry to a linked list of arguments
346  */
347 void
348 addarg(type, arg)
349 	int type;
350 	char *arg;
351 {
352 	ARG *cur;
353 
354 	if (!(cur = (ARG *)malloc((u_int)sizeof(ARG))))
355 		err(1, "malloc failure");
356 	cur->next = arglist;
357 	cur->type = type;
358 	cur->name = arg;
359 	arglist = cur;
360 }
361 
362 /*
363  * addtty --
364  *	add an entry to a linked list of ttys
365  */
366 TTY *
367 addtty(ttyname)
368 	char *ttyname;
369 {
370 	TTY *cur;
371 
372 	if (!(cur = (TTY *)malloc((u_int)sizeof(TTY))))
373 		err(1, "malloc failure");
374 	cur->next = ttylist;
375 	cur->logout = currentout;
376 	memmove(cur->tty, ttyname, UT_LINESIZE);
377 	return (ttylist = cur);
378 }
379 
380 /*
381  * hostconv --
382  *	convert the hostname to search pattern; if the supplied host name
383  *	has a domain attached that is the same as the current domain, rip
384  *	off the domain suffix since that's what login(1) does.
385  */
386 void
387 hostconv(arg)
388 	char *arg;
389 {
390 	static int first = 1;
391 	static char *hostdot, name[MAXHOSTNAMELEN + 1];
392 	char *argdot;
393 
394 	if (!(argdot = strchr(arg, '.')))
395 		return;
396 	if (first) {
397 		first = 0;
398 		if (gethostname(name, sizeof(name)))
399 			err(1, "gethostname");
400 		name[sizeof(name) - 1] = '\0';
401 		hostdot = strchr(name, '.');
402 	}
403 	if (hostdot && !strcasecmp(hostdot, argdot))
404 		*argdot = '\0';
405 }
406 
407 /*
408  * ttyconv --
409  *	convert tty to correct name.
410  */
411 char *
412 ttyconv(arg)
413 	char *arg;
414 {
415 	char *mval;
416 
417 	/*
418 	 * kludge -- we assume that all tty's end with
419 	 * a two character suffix.
420 	 */
421 	if (strlen(arg) == 2) {
422 		/* either 6 for "ttyxx" or 8 for "console" */
423 		if (!(mval = malloc((u_int)8)))
424 			err(1, "malloc failure");
425 		if (!strcmp(arg, "co"))
426 			(void)strcpy(mval, "console");
427 		else {
428 			(void)strcpy(mval, "tty");
429 			(void)strcpy(mval + 3, arg);
430 		}
431 		return (mval);
432 	}
433 	if (!strncmp(arg, _PATH_DEV, sizeof(_PATH_DEV) - 1))
434 		return (arg + 5);
435 	return (arg);
436 }
437 
438 /*
439  * fmttime --
440  *	return pointer to (static) formatted time string.
441  */
442 char *
443 fmttime(t, flags)
444 	time_t t;
445 	int flags;
446 {
447 	struct tm *tm;
448 	static char tbuf[TBUFLEN];
449 
450 	tm = (flags & GMT) ? gmtime(&t) : localtime(&t);
451 	strftime(tbuf, sizeof(tbuf),
452 	    (flags & TIMEONLY)
453 	     ? (flags & FULLTIME ? LTFMTS : TFMTS)
454 	     : (flags & FULLTIME ? LTFMT : TFMT),
455 	    tm);
456 	return (tbuf);
457 }
458 
459 /*
460  * onintr --
461  *	on interrupt, we inform the user how far we've gotten
462  */
463 void
464 onintr(signo)
465 	int signo;
466 {
467 
468 	printf("\ninterrupted %s\n", fmttime(buf[0].ut_time, FULLTIME));
469 	if (signo == SIGINT)
470 		exit(1);
471 	(void)fflush(stdout);		/* fix required for rsh */
472 }
473