xref: /freebsd/usr.bin/last/last.c (revision b601c69bdbe8755d26570261d7fd4c02ee4eff74)
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  * $FreeBSD$
34  */
35 
36 #ifndef lint
37 static char copyright[] =
38 "@(#) Copyright (c) 1987, 1993, 1994\n\
39 	The Regents of the University of California.  All rights reserved.\n";
40 #endif /* not lint */
41 
42 #ifndef lint
43 static char sccsid[] = "@(#)last.c	8.2 (Berkeley) 4/2/94";
44 #endif /* not lint */
45 
46 #include <sys/param.h>
47 #include <sys/stat.h>
48 
49 #include <err.h>
50 #include <fcntl.h>
51 #include <locale.h>
52 #include <paths.h>
53 #include <signal.h>
54 #include <stdio.h>
55 #include <stdlib.h>
56 #include <string.h>
57 #include <time.h>
58 #include <unistd.h>
59 #include <utmp.h>
60 #include <sys/queue.h>
61 
62 #define	NO	0				/* false/no */
63 #define	YES	1				/* true/yes */
64 
65 static struct utmp	buf[1024];		/* utmp read buffer */
66 
67 typedef struct arg {
68 	char	*name;				/* argument */
69 #define	HOST_TYPE	-2
70 #define	TTY_TYPE	-3
71 #define	USER_TYPE	-4
72 	int	type;				/* type of arg */
73 	struct arg	*next;			/* linked list pointer */
74 } ARG;
75 ARG	*arglist;				/* head of linked list */
76 
77 LIST_HEAD(ttylisthead, ttytab) ttylist;
78 
79 struct ttytab {
80 	time_t	logout;				/* log out time */
81 	char	tty[UT_LINESIZE + 1];		/* terminal name */
82 	LIST_ENTRY(ttytab) list;
83 };
84 
85 static long	currentout,			/* current logout value */
86 		maxrec;				/* records to display */
87 static char	*file = _PATH_WTMP;		/* wtmp file */
88 static int	sflag = 0;			/* show delta in seconds */
89 static int	width = 5;			/* show seconds in delta */
90 
91 void	 addarg __P((int, char *));
92 void	 hostconv __P((char *));
93 void	 onintr __P((int));
94 char	*ttyconv __P((char *));
95 int	 want __P((struct utmp *));
96 void	 wtmp __P((void));
97 
98 void
99 usage(void)
100 {
101 	(void)fprintf(stderr,
102 	"usage: last [-#] [-f file] [-h hostname] [-t tty] [-s|w] [user ...]\n");
103 	exit(1);
104 }
105 
106 int
107 main(argc, argv)
108 	int argc;
109 	char *argv[];
110 {
111 	extern int optind;
112 	extern char *optarg;
113 	int ch;
114 	char *p;
115 
116 	(void) setlocale(LC_TIME, "");
117 
118 	maxrec = -1;
119 	while ((ch = getopt(argc, argv, "0123456789f:h:st:w")) != -1)
120 		switch (ch) {
121 		case '0': case '1': case '2': case '3': case '4':
122 		case '5': case '6': case '7': case '8': case '9':
123 			/*
124 			 * kludge: last was originally designed to take
125 			 * a number after a dash.
126 			 */
127 			if (maxrec == -1) {
128 				p = argv[optind - 1];
129 				if (p[0] == '-' && p[1] == ch && !p[2])
130 					maxrec = atol(++p);
131 				else
132 					maxrec = atol(argv[optind] + 1);
133 				if (!maxrec)
134 					exit(0);
135 			}
136 			break;
137 		case 'f':
138 			file = optarg;
139 			break;
140 		case 'h':
141 			hostconv(optarg);
142 			addarg(HOST_TYPE, optarg);
143 			break;
144 		case 's':
145 			sflag++;	/* Show delta as seconds */
146 			break;
147 		case 't':
148 			addarg(TTY_TYPE, ttyconv(optarg));
149 			break;
150 		case 'w':
151 			width = 8;
152 			break;
153 		case '?':
154 		default:
155 			usage();
156 		}
157 
158 	if (sflag && width == 8) usage();
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 	struct ttytab	*tt, *ttx;		/* ttylist entry */
184 	struct stat	stb;			/* stat of file for size */
185 	long	bl;
186 	time_t	delta;				/* time difference */
187 	int	bytes, wfd;
188 	char    *crmsg;
189 	char ct[80];
190 	struct tm *tm;
191 
192 	LIST_INIT(&ttylist);
193 
194 	if ((wfd = open(file, O_RDONLY, 0)) < 0 || fstat(wfd, &stb) == -1)
195 		err(1, "%s", file);
196 	bl = (stb.st_size + sizeof(buf) - 1) / sizeof(buf);
197 
198 	(void)time(&buf[0].ut_time);
199 	(void)signal(SIGINT, onintr);
200 	(void)signal(SIGQUIT, onintr);
201 
202 	while (--bl >= 0) {
203 		if (lseek(wfd, (off_t)(bl * sizeof(buf)), L_SET) == -1 ||
204 		    (bytes = read(wfd, buf, sizeof(buf))) == -1)
205 			err(1, "%s", file);
206 		for (bp = &buf[bytes / sizeof(buf[0]) - 1]; bp >= buf; --bp) {
207 			/*
208 			 * if the terminal line is '~', the machine stopped.
209 			 * see utmp(5) for more info.
210 			 */
211 			if (bp->ut_line[0] == '~' && !bp->ut_line[1]) {
212 				/* everybody just logged out */
213 				for (tt = ttylist.lh_first; tt;) {
214 					LIST_REMOVE(tt, list);
215 					ttx = tt;
216 					tt = tt->list.le_next;
217 					free(ttx);
218 				}
219 				currentout = -bp->ut_time;
220 				crmsg = strncmp(bp->ut_name, "shutdown",
221 				    UT_NAMESIZE) ? "crash" : "shutdown";
222 				if (want(bp)) {
223 					tm = localtime(&bp->ut_time);
224 					(void) strftime(ct, sizeof(ct), "%c", tm);
225 					printf("%-*.*s %-*.*s %-*.*s %10.10s %5.5s \n",
226 					    UT_NAMESIZE, UT_NAMESIZE,
227 					    bp->ut_name, UT_LINESIZE,
228 					    UT_LINESIZE, bp->ut_line,
229 					    UT_HOSTSIZE, UT_HOSTSIZE,
230 					    bp->ut_host, ct, ct + 11);
231 					if (maxrec != -1 && !--maxrec)
232 						return;
233 				}
234 				continue;
235 			}
236 			/*
237 			 * if the line is '{' or '|', date got set; see
238 			 * utmp(5) for more info.
239 			 */
240 			if ((bp->ut_line[0] == '{' || bp->ut_line[0] == '|')
241 			    && !bp->ut_line[1]) {
242 				if (want(bp)) {
243 					tm = localtime(&bp->ut_time);
244 					(void) strftime(ct, sizeof(ct), "%c", tm);
245 					printf("%-*.*s %-*.*s %-*.*s %10.10s %5.5s \n",
246 					    UT_NAMESIZE, UT_NAMESIZE, bp->ut_name,
247 					    UT_LINESIZE, UT_LINESIZE, bp->ut_line,
248 					    UT_HOSTSIZE, UT_HOSTSIZE, bp->ut_host,
249 					    ct, ct + 11);
250 					if (maxrec && !--maxrec)
251 						return;
252 				}
253 				continue;
254 			}
255 			if (bp->ut_name[0] == '\0' || want(bp)) {
256 				/* find associated tty */
257 				for (tt = ttylist.lh_first; ; tt = tt->list.le_next) {
258 					if (tt == NULL) {
259 						/* add new one */
260 						tt = malloc(sizeof(struct ttytab));
261 						if (tt == NULL)
262 							err(1, "malloc failure");
263 						tt->logout = currentout;
264 						strncpy(tt->tty, bp->ut_line, UT_LINESIZE);
265 						LIST_INSERT_HEAD(&ttylist, tt, list);
266 						break;
267 					}
268 					if (!strncmp(tt->tty, bp->ut_line, UT_LINESIZE))
269 						break;
270 				}
271 				if (bp->ut_name[0]) {
272 					/*
273 					 * when uucp and ftp log in over a network, the entry in
274 					 * the utmp file is the name plus their process id.  See
275 					 * etc/ftpd.c and usr.bin/uucp/uucpd.c for more information.
276 					 */
277 					if (!strncmp(bp->ut_line, "ftp", sizeof("ftp") - 1))
278 						bp->ut_line[3] = '\0';
279 					else if (!strncmp(bp->ut_line, "uucp", sizeof("uucp") - 1))
280 						bp->ut_line[4] = '\0';
281 					tm = localtime(&bp->ut_time);
282 					(void) strftime(ct, sizeof(ct), "%c", tm);
283 					printf("%-*.*s %-*.*s %-*.*s %10.10s %5.5s ",
284 					    UT_NAMESIZE, UT_NAMESIZE, bp->ut_name,
285 					    UT_LINESIZE, UT_LINESIZE, bp->ut_line,
286 					    UT_HOSTSIZE, UT_HOSTSIZE, bp->ut_host,
287 					    ct, ct + 11);
288 					if (!tt->logout)
289 						puts("  still logged in");
290 					else {
291 						if (tt->logout < 0) {
292 							tt->logout = -tt->logout;
293 							printf("- %s", crmsg);
294 						}
295 						else {
296 							tm = localtime(&tt->logout);
297 							(void) strftime(ct, sizeof(ct), "%c", tm);
298 							printf("- %5.5s", ct + 11);
299 						}
300 						delta = tt->logout - bp->ut_time;
301 						if ( sflag ) {
302 							printf("  (%8lu)\n",
303 								delta);
304 						} else {
305 						    tm = gmtime(&delta);
306 						    (void) strftime(ct, sizeof(ct), "%c", tm);
307 						    if (delta < 86400)
308 							printf("  (%*.*s)\n", width, width, ct + 11);
309 						    else
310 							printf(" (%ld+%*.*s)\n",
311 							    delta / 86400, width, width, ct + 11);
312 						}
313 					}
314 					LIST_REMOVE(tt, list);
315 					free(tt);
316 					if (maxrec != -1 && !--maxrec)
317 						return;
318 				} else {
319 					tt->logout = bp->ut_time;
320 				}
321 			}
322 		}
323 	}
324 	tm = localtime(&buf[0].ut_time);
325 	(void) strftime(ct, sizeof(ct), "\nwtmp begins %c\n", tm);
326 	printf("%s", ct);
327 }
328 
329 /*
330  * want --
331  *	see if want this entry
332  */
333 int
334 want(bp)
335 	struct utmp *bp;
336 {
337 	ARG *step;
338 
339 	if (!arglist)
340 		return (YES);
341 
342 	for (step = arglist; step; step = step->next)
343 		switch(step->type) {
344 		case HOST_TYPE:
345 			if (!strncasecmp(step->name, bp->ut_host, UT_HOSTSIZE))
346 				return (YES);
347 			break;
348 		case TTY_TYPE:
349 			if (!strncmp(step->name, bp->ut_line, UT_LINESIZE))
350 				return (YES);
351 			break;
352 		case USER_TYPE:
353 			if (!strncmp(step->name, bp->ut_name, UT_NAMESIZE))
354 				return (YES);
355 			break;
356 	}
357 	return (NO);
358 }
359 
360 /*
361  * addarg --
362  *	add an entry to a linked list of arguments
363  */
364 void
365 addarg(type, arg)
366 	int type;
367 	char *arg;
368 {
369 	ARG *cur;
370 
371 	if (!(cur = (ARG *)malloc((u_int)sizeof(ARG))))
372 		err(1, "malloc failure");
373 	cur->next = arglist;
374 	cur->type = type;
375 	cur->name = arg;
376 	arglist = cur;
377 }
378 
379 /*
380  * hostconv --
381  *	convert the hostname to search pattern; if the supplied host name
382  *	has a domain attached that is the same as the current domain, rip
383  *	off the domain suffix since that's what login(1) does.
384  */
385 void
386 hostconv(arg)
387 	char *arg;
388 {
389 	static int first = 1;
390 	static char *hostdot, name[MAXHOSTNAMELEN];
391 	char *argdot;
392 
393 	if (!(argdot = strchr(arg, '.')))
394 		return;
395 	if (first) {
396 		first = 0;
397 		if (gethostname(name, sizeof(name)))
398 			err(1, "gethostname");
399 		hostdot = strchr(name, '.');
400 	}
401 	if (hostdot && !strcasecmp(hostdot, argdot))
402 		*argdot = '\0';
403 }
404 
405 /*
406  * ttyconv --
407  *	convert tty to correct name.
408  */
409 char *
410 ttyconv(arg)
411 	char *arg;
412 {
413 	char *mval;
414 
415 	/*
416 	 * kludge -- we assume that all tty's end with
417 	 * a two character suffix.
418 	 */
419 	if (strlen(arg) == 2) {
420 		/* either 6 for "ttyxx" or 8 for "console" */
421 		if (!(mval = malloc((u_int)8)))
422 			err(1, "malloc failure");
423 		if (!strcmp(arg, "co"))
424 			(void)strcpy(mval, "console");
425 		else {
426 			(void)strcpy(mval, "tty");
427 			(void)strcpy(mval + 3, arg);
428 		}
429 		return (mval);
430 	}
431 	if (!strncmp(arg, _PATH_DEV, sizeof(_PATH_DEV) - 1))
432 		return (arg + 5);
433 	return (arg);
434 }
435 
436 /*
437  * onintr --
438  *	on interrupt, we inform the user how far we've gotten
439  */
440 void
441 onintr(signo)
442 	int signo;
443 {
444 	char ct[80];
445 	struct tm *tm;
446 
447 	tm = localtime(&buf[0].ut_time);
448 	(void) strftime(ct, sizeof(ct), "%c", tm);
449 	printf("\ninterrupted %10.10s %5.5s \n", ct, ct + 11);
450 	if (signo == SIGINT)
451 		exit(1);
452 	(void)fflush(stdout);			/* fix required for rsh */
453 }
454