xref: /netbsd-src/usr.bin/last/last.c (revision ae9172d6cd9432a6a1a56760d86b32c57a66c39c)
1 /*	$NetBSD: last.c,v 1.5 1994/12/21 22:41:25 jtc 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 #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 #if 0
44 static char sccsid[] = "@(#)last.c	8.2 (Berkeley) 4/2/94";
45 #endif
46 static char rcsid[] = "$NetBSD: last.c,v 1.5 1994/12/21 22:41:25 jtc Exp $";
47 #endif /* not lint */
48 
49 #include <sys/param.h>
50 #include <sys/stat.h>
51 
52 #include <err.h>
53 #include <fcntl.h>
54 #include <paths.h>
55 #include <signal.h>
56 #include <stdio.h>
57 #include <stdlib.h>
58 #include <string.h>
59 #include <time.h>
60 #include <tzfile.h>
61 #include <unistd.h>
62 #include <utmp.h>
63 
64 #define	NO	0				/* false/no */
65 #define	YES	1				/* true/yes */
66 
67 static struct utmp	buf[1024];		/* utmp read buffer */
68 
69 typedef struct arg {
70 	char	*name;				/* argument */
71 #define	HOST_TYPE	-2
72 #define	TTY_TYPE	-3
73 #define	USER_TYPE	-4
74 	int	type;				/* type of arg */
75 	struct arg	*next;			/* linked list pointer */
76 } ARG;
77 ARG	*arglist;				/* head of linked list */
78 
79 typedef struct ttytab {
80 	long	logout;				/* log out time */
81 	char	tty[UT_LINESIZE + 1];		/* terminal name */
82 	struct ttytab	*next;			/* linked list pointer */
83 } TTY;
84 TTY	*ttylist;				/* head of linked list */
85 
86 static long	currentout,			/* current logout value */
87 		maxrec;				/* records to display */
88 static char	*file = _PATH_WTMP;		/* wtmp file */
89 
90 void	 addarg __P((int, char *));
91 TTY	*addtty __P((char *));
92 void	 hostconv __P((char *));
93 void	 onintr __P((int));
94 char	*ttyconv __P((char *));
95 int	 want __P((struct utmp *, int));
96 void	 wtmp __P((void));
97 
98 int
99 main(argc, argv)
100 	int argc;
101 	char *argv[];
102 {
103 	extern int optind;
104 	extern char *optarg;
105 	int ch;
106 	char *p;
107 
108 	maxrec = -1;
109 	while ((ch = getopt(argc, argv, "0123456789f:h:t:")) != EOF)
110 		switch (ch) {
111 		case '0': case '1': case '2': case '3': case '4':
112 		case '5': case '6': case '7': case '8': case '9':
113 			/*
114 			 * kludge: last was originally designed to take
115 			 * a number after a dash.
116 			 */
117 			if (maxrec == -1) {
118 				p = argv[optind - 1];
119 				if (p[0] == '-' && p[1] == ch && !p[2])
120 					maxrec = atol(++p);
121 				else
122 					maxrec = atol(argv[optind] + 1);
123 				if (!maxrec)
124 					exit(0);
125 			}
126 			break;
127 		case 'f':
128 			file = optarg;
129 			break;
130 		case 'h':
131 			hostconv(optarg);
132 			addarg(HOST_TYPE, optarg);
133 			break;
134 		case 't':
135 			addarg(TTY_TYPE, ttyconv(optarg));
136 			break;
137 		case '?':
138 		default:
139 			(void)fprintf(stderr,
140 	"usage: last [-#] [-f file] [-t tty] [-h hostname] [user ...]\n");
141 			exit(1);
142 		}
143 
144 	if (argc) {
145 		setlinebuf(stdout);
146 		for (argv += optind; *argv; ++argv) {
147 #define	COMPATIBILITY
148 #ifdef	COMPATIBILITY
149 			/* code to allow "last p5" to work */
150 			addarg(TTY_TYPE, ttyconv(*argv));
151 #endif
152 			addarg(USER_TYPE, *argv);
153 		}
154 	}
155 	wtmp();
156 	exit(0);
157 }
158 
159 /*
160  * wtmp --
161  *	read through the wtmp file
162  */
163 void
164 wtmp()
165 {
166 	struct utmp	*bp;			/* current structure */
167 	TTY	*T;				/* tty list entry */
168 	struct stat	stb;			/* stat of file for size */
169 	long	bl, delta;			/* time difference */
170 	int	bytes, wfd;
171 	char	*ct, *crmsg;
172 
173 	if ((wfd = open(file, O_RDONLY, 0)) < 0 || fstat(wfd, &stb) == -1)
174 		err(1, "%s", file);
175 	bl = (stb.st_size + sizeof(buf) - 1) / sizeof(buf);
176 
177 	(void)time(&buf[0].ut_time);
178 	(void)signal(SIGINT, onintr);
179 	(void)signal(SIGQUIT, onintr);
180 
181 	while (--bl >= 0) {
182 		if (lseek(wfd, (off_t)(bl * sizeof(buf)), L_SET) == -1 ||
183 		    (bytes = read(wfd, buf, sizeof(buf))) == -1)
184 			err(1, "%s", file);
185 		for (bp = &buf[bytes / sizeof(buf[0]) - 1]; bp >= buf; --bp) {
186 			/*
187 			 * if the terminal line is '~', the machine stopped.
188 			 * see utmp(5) for more info.
189 			 */
190 			if (bp->ut_line[0] == '~' && !bp->ut_line[1]) {
191 				/* everybody just logged out */
192 				for (T = ttylist; T; T = T->next)
193 					T->logout = -bp->ut_time;
194 				currentout = -bp->ut_time;
195 				crmsg = strncmp(bp->ut_name, "shutdown",
196 				    UT_NAMESIZE) ? "crash" : "shutdown";
197 				if (want(bp, NO)) {
198 					ct = ctime(&bp->ut_time);
199 				printf("%-*.*s  %-*.*s %-*.*s %10.10s %5.5s \n",
200 					    UT_NAMESIZE, UT_NAMESIZE,
201 					    bp->ut_name, UT_LINESIZE,
202 					    UT_LINESIZE, bp->ut_line,
203 					    UT_HOSTSIZE, UT_HOSTSIZE,
204 					    bp->ut_host, ct, ct + 11);
205 					if (maxrec != -1 && !--maxrec)
206 						return;
207 				}
208 				continue;
209 			}
210 			/*
211 			 * if the line is '{' or '|', date got set; see
212 			 * utmp(5) for more info.
213 			 */
214 			if ((bp->ut_line[0] == '{' || bp->ut_line[0] == '|')
215 			    && !bp->ut_line[1]) {
216 				if (want(bp, NO)) {
217 					ct = ctime(&bp->ut_time);
218 				printf("%-*.*s  %-*.*s %-*.*s %10.10s %5.5s \n",
219 				    UT_NAMESIZE, UT_NAMESIZE, bp->ut_name,
220 				    UT_LINESIZE, UT_LINESIZE, bp->ut_line,
221 				    UT_HOSTSIZE, UT_HOSTSIZE, bp->ut_host,
222 				    ct, ct + 11);
223 					if (maxrec && !--maxrec)
224 						return;
225 				}
226 				continue;
227 			}
228 			/* find associated tty */
229 			for (T = ttylist;; T = T->next) {
230 				if (!T) {
231 					/* add new one */
232 					T = addtty(bp->ut_line);
233 					break;
234 				}
235 				if (!strncmp(T->tty, bp->ut_line, UT_LINESIZE))
236 					break;
237 			}
238 			if (bp->ut_name[0] && want(bp, YES)) {
239 				ct = ctime(&bp->ut_time);
240 				printf("%-*.*s  %-*.*s %-*.*s %10.10s %5.5s ",
241 				UT_NAMESIZE, UT_NAMESIZE, bp->ut_name,
242 				UT_LINESIZE, UT_LINESIZE, bp->ut_line,
243 				UT_HOSTSIZE, UT_HOSTSIZE, bp->ut_host,
244 				ct, ct + 11);
245 				if (!T->logout)
246 					puts("  still logged in");
247 				else {
248 					if (T->logout < 0) {
249 						T->logout = -T->logout;
250 						printf("- %s", crmsg);
251 					}
252 					else
253 						printf("- %5.5s",
254 						    ctime(&T->logout)+11);
255 					delta = T->logout - bp->ut_time;
256 					if (delta < SECSPERDAY)
257 						printf("  (%5.5s)\n",
258 						    asctime(gmtime(&delta))+11);
259 					else
260 						printf(" (%ld+%5.5s)\n",
261 						    delta / SECSPERDAY,
262 						    asctime(gmtime(&delta))+11);
263 				}
264 				if (maxrec != -1 && !--maxrec)
265 					return;
266 			}
267 			T->logout = bp->ut_time;
268 		}
269 	}
270 	ct = ctime(&buf[0].ut_time);
271 	printf("\nwtmp begins %10.10s %5.5s \n", ct, ct + 11);
272 }
273 
274 /*
275  * want --
276  *	see if want this entry
277  */
278 int
279 want(bp, check)
280 	struct utmp *bp;
281 	int check;
282 {
283 	ARG *step;
284 
285 	if (check)
286 		/*
287 		 * when uucp and ftp log in over a network, the entry in
288 		 * the utmp file is the name plus their process id.  See
289 		 * etc/ftpd.c and usr.bin/uucp/uucpd.c for more information.
290 		 */
291 		if (!strncmp(bp->ut_line, "ftp", sizeof("ftp") - 1))
292 			bp->ut_line[3] = '\0';
293 		else if (!strncmp(bp->ut_line, "uucp", sizeof("uucp") - 1))
294 			bp->ut_line[4] = '\0';
295 	if (!arglist)
296 		return (YES);
297 
298 	for (step = arglist; step; step = step->next)
299 		switch(step->type) {
300 		case HOST_TYPE:
301 			if (!strncasecmp(step->name, bp->ut_host, UT_HOSTSIZE))
302 				return (YES);
303 			break;
304 		case TTY_TYPE:
305 			if (!strncmp(step->name, bp->ut_line, UT_LINESIZE))
306 				return (YES);
307 			break;
308 		case USER_TYPE:
309 			if (!strncmp(step->name, bp->ut_name, UT_NAMESIZE))
310 				return (YES);
311 			break;
312 	}
313 	return (NO);
314 }
315 
316 /*
317  * addarg --
318  *	add an entry to a linked list of arguments
319  */
320 void
321 addarg(type, arg)
322 	int type;
323 	char *arg;
324 {
325 	ARG *cur;
326 
327 	if (!(cur = (ARG *)malloc((u_int)sizeof(ARG))))
328 		err(1, "malloc failure");
329 	cur->next = arglist;
330 	cur->type = type;
331 	cur->name = arg;
332 	arglist = cur;
333 }
334 
335 /*
336  * addtty --
337  *	add an entry to a linked list of ttys
338  */
339 TTY *
340 addtty(ttyname)
341 	char *ttyname;
342 {
343 	TTY *cur;
344 
345 	if (!(cur = (TTY *)malloc((u_int)sizeof(TTY))))
346 		err(1, "malloc failure");
347 	cur->next = ttylist;
348 	cur->logout = currentout;
349 	memmove(cur->tty, ttyname, UT_LINESIZE);
350 	return (ttylist = cur);
351 }
352 
353 /*
354  * hostconv --
355  *	convert the hostname to search pattern; if the supplied host name
356  *	has a domain attached that is the same as the current domain, rip
357  *	off the domain suffix since that's what login(1) does.
358  */
359 void
360 hostconv(arg)
361 	char *arg;
362 {
363 	static int first = 1;
364 	static char *hostdot, name[MAXHOSTNAMELEN];
365 	char *argdot;
366 
367 	if (!(argdot = strchr(arg, '.')))
368 		return;
369 	if (first) {
370 		first = 0;
371 		if (gethostname(name, sizeof(name)))
372 			err(1, "gethostname");
373 		hostdot = strchr(name, '.');
374 	}
375 	if (hostdot && !strcasecmp(hostdot, argdot))
376 		*argdot = '\0';
377 }
378 
379 /*
380  * ttyconv --
381  *	convert tty to correct name.
382  */
383 char *
384 ttyconv(arg)
385 	char *arg;
386 {
387 	char *mval;
388 
389 	/*
390 	 * kludge -- we assume that all tty's end with
391 	 * a two character suffix.
392 	 */
393 	if (strlen(arg) == 2) {
394 		/* either 6 for "ttyxx" or 8 for "console" */
395 		if (!(mval = malloc((u_int)8)))
396 			err(1, "malloc failure");
397 		if (!strcmp(arg, "co"))
398 			(void)strcpy(mval, "console");
399 		else {
400 			(void)strcpy(mval, "tty");
401 			(void)strcpy(mval + 3, arg);
402 		}
403 		return (mval);
404 	}
405 	if (!strncmp(arg, _PATH_DEV, sizeof(_PATH_DEV) - 1))
406 		return (arg + 5);
407 	return (arg);
408 }
409 
410 /*
411  * onintr --
412  *	on interrupt, we inform the user how far we've gotten
413  */
414 void
415 onintr(signo)
416 	int signo;
417 {
418 	char *ct;
419 
420 	ct = ctime(&buf[0].ut_time);
421 	printf("\ninterrupted %10.10s %5.5s \n", ct, ct + 11);
422 	if (signo == SIGINT)
423 		exit(1);
424 	(void)fflush(stdout);			/* fix required for rsh */
425 }
426