last.c revision 74588 
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: head/usr.bin/last/last.c 74588 2001-03-21 19:08:01Z ache $
34 */
35
36#ifndef lint
37static 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
43static 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 <langinfo.h>
52#include <locale.h>
53#include <paths.h>
54#include <signal.h>
55#include <stdio.h>
56#include <stdlib.h>
57#include <string.h>
58#include <time.h>
59#include <unistd.h>
60#include <utmp.h>
61#include <sys/queue.h>
62
63#define	NO	0				/* false/no */
64#define	YES	1				/* true/yes */
65
66static struct utmp	buf[1024];		/* utmp read buffer */
67
68typedef struct arg {
69	char	*name;				/* argument */
70#define	HOST_TYPE	-2
71#define	TTY_TYPE	-3
72#define	USER_TYPE	-4
73	int	type;				/* type of arg */
74	struct arg	*next;			/* linked list pointer */
75} ARG;
76ARG	*arglist;				/* head of linked list */
77
78LIST_HEAD(ttylisthead, ttytab) ttylist;
79
80struct ttytab {
81	time_t	logout;				/* log out time */
82	char	tty[UT_LINESIZE + 1];		/* terminal name */
83	LIST_ENTRY(ttytab) list;
84};
85
86static long	currentout,			/* current logout value */
87		maxrec;				/* records to display */
88static char	*file = _PATH_WTMP;		/* wtmp file */
89static int	sflag = 0;			/* show delta in seconds */
90static int	width = 5;			/* show seconds in delta */
91static int      d_first;
92
93void	 addarg __P((int, char *));
94void	 hostconv __P((char *));
95void	 onintr __P((int));
96char	*ttyconv __P((char *));
97int	 want __P((struct utmp *));
98void	 wtmp __P((void));
99
100void
101usage(void)
102{
103	(void)fprintf(stderr,
104	"usage: last [-#] [-f file] [-h hostname] [-t tty] [-s|w] [user ...]\n");
105	exit(1);
106}
107
108int
109main(argc, argv)
110	int argc;
111	char *argv[];
112{
113	int ch;
114	char *p;
115
116	(void) setlocale(LC_TIME, "");
117	d_first = (*nl_langinfo(D_MD_ORDER) == 'd');
118
119	maxrec = -1;
120	while ((ch = getopt(argc, argv, "0123456789f:h:st:w")) != -1)
121		switch (ch) {
122		case '0': case '1': case '2': case '3': case '4':
123		case '5': case '6': case '7': case '8': case '9':
124			/*
125			 * kludge: last was originally designed to take
126			 * a number after a dash.
127			 */
128			if (maxrec == -1) {
129				p = argv[optind - 1];
130				if (p[0] == '-' && p[1] == ch && !p[2])
131					maxrec = atol(++p);
132				else
133					maxrec = atol(argv[optind] + 1);
134				if (!maxrec)
135					exit(0);
136			}
137			break;
138		case 'f':
139			file = optarg;
140			break;
141		case 'h':
142			hostconv(optarg);
143			addarg(HOST_TYPE, optarg);
144			break;
145		case 's':
146			sflag++;	/* Show delta as seconds */
147			break;
148		case 't':
149			addarg(TTY_TYPE, ttyconv(optarg));
150			break;
151		case 'w':
152			width = 8;
153			break;
154		case '?':
155		default:
156			usage();
157		}
158
159	if (sflag && width == 8) usage();
160
161	if (argc) {
162		setlinebuf(stdout);
163		for (argv += optind; *argv; ++argv) {
164#define	COMPATIBILITY
165#ifdef	COMPATIBILITY
166			/* code to allow "last p5" to work */
167			addarg(TTY_TYPE, ttyconv(*argv));
168#endif
169			addarg(USER_TYPE, *argv);
170		}
171	}
172	wtmp();
173	exit(0);
174}
175
176/*
177 * wtmp --
178 *	read through the wtmp file
179 */
180void
181wtmp()
182{
183	struct utmp	*bp;			/* current structure */
184	struct ttytab	*tt, *ttx;		/* ttylist entry */
185	struct stat	stb;			/* stat of file for size */
186	long	bl;
187	time_t	delta;				/* time difference */
188	int	bytes, wfd;
189	char    *crmsg;
190	char ct[80];
191	struct tm *tm;
192
193	LIST_INIT(&ttylist);
194
195	if ((wfd = open(file, O_RDONLY, 0)) < 0 || fstat(wfd, &stb) == -1)
196		err(1, "%s", file);
197	bl = (stb.st_size + sizeof(buf) - 1) / sizeof(buf);
198
199	(void)time(&buf[0].ut_time);
200	(void)signal(SIGINT, onintr);
201	(void)signal(SIGQUIT, onintr);
202
203	while (--bl >= 0) {
204		if (lseek(wfd, (off_t)(bl * sizeof(buf)), L_SET) == -1 ||
205		    (bytes = read(wfd, buf, sizeof(buf))) == -1)
206			err(1, "%s", file);
207		for (bp = &buf[bytes / sizeof(buf[0]) - 1]; bp >= buf; --bp) {
208			/*
209			 * if the terminal line is '~', the machine stopped.
210			 * see utmp(5) for more info.
211			 */
212			if (bp->ut_line[0] == '~' && !bp->ut_line[1]) {
213				/* everybody just logged out */
214				for (tt = LIST_FIRST(&ttylist); tt;) {
215					LIST_REMOVE(tt, list);
216					ttx = tt;
217					tt = LIST_NEXT(tt, list);
218					free(ttx);
219				}
220				currentout = -bp->ut_time;
221				crmsg = strncmp(bp->ut_name, "shutdown",
222				    UT_NAMESIZE) ? "crash" : "shutdown";
223				if (want(bp)) {
224					tm = localtime(&bp->ut_time);
225					(void) strftime(ct, sizeof(ct),
226						     d_first ? "%a %e %b %R" :
227							       "%a %b %e %R",
228						     tm);
229					printf("%-*.*s %-*.*s %-*.*s %s\n",
230					    UT_NAMESIZE, UT_NAMESIZE,
231					    bp->ut_name, UT_LINESIZE,
232					    UT_LINESIZE, bp->ut_line,
233					    UT_HOSTSIZE, UT_HOSTSIZE,
234					    bp->ut_host, ct);
235					if (maxrec != -1 && !--maxrec)
236						return;
237				}
238				continue;
239			}
240			/*
241			 * if the line is '{' or '|', date got set; see
242			 * utmp(5) for more info.
243			 */
244			if ((bp->ut_line[0] == '{' || bp->ut_line[0] == '|')
245			    && !bp->ut_line[1]) {
246				if (want(bp)) {
247					tm = localtime(&bp->ut_time);
248					(void) strftime(ct, sizeof(ct),
249						     d_first ? "%a %e %b %R" :
250							       "%a %b %e %R",
251						     tm);
252					printf("%-*.*s %-*.*s %-*.*s %s\n",
253					    UT_NAMESIZE, UT_NAMESIZE, bp->ut_name,
254					    UT_LINESIZE, UT_LINESIZE, bp->ut_line,
255					    UT_HOSTSIZE, UT_HOSTSIZE, bp->ut_host,
256					    ct);
257					if (maxrec && !--maxrec)
258						return;
259				}
260				continue;
261			}
262			if (bp->ut_name[0] == '\0' || want(bp)) {
263				/* find associated tty */
264				LIST_FOREACH(tt, &ttylist, list)
265					if (!strncmp(tt->tty, bp->ut_line, UT_LINESIZE))
266						break;
267
268				if (tt == NULL) {
269					/* add new one */
270					tt = malloc(sizeof(struct ttytab));
271					if (tt == NULL)
272						err(1, "malloc failure");
273					tt->logout = currentout;
274					strncpy(tt->tty, bp->ut_line, UT_LINESIZE);
275					LIST_INSERT_HEAD(&ttylist, tt, list);
276				}
277
278				if (bp->ut_name[0]) {
279					/*
280					 * when uucp and ftp log in over a network, the entry in
281					 * the utmp file is the name plus their process id.  See
282					 * etc/ftpd.c and usr.bin/uucp/uucpd.c for more information.
283					 */
284					if (!strncmp(bp->ut_line, "ftp", sizeof("ftp") - 1))
285						bp->ut_line[3] = '\0';
286					else if (!strncmp(bp->ut_line, "uucp", sizeof("uucp") - 1))
287						bp->ut_line[4] = '\0';
288					tm = localtime(&bp->ut_time);
289					(void) strftime(ct, sizeof(ct),
290						     d_first ? "%a %e %b %R" :
291							       "%a %b %e %R",
292						     tm);
293					printf("%-*.*s %-*.*s %-*.*s %s ",
294					    UT_NAMESIZE, UT_NAMESIZE, bp->ut_name,
295					    UT_LINESIZE, UT_LINESIZE, bp->ut_line,
296					    UT_HOSTSIZE, UT_HOSTSIZE, bp->ut_host,
297					    ct);
298					if (!tt->logout)
299						puts("  still logged in");
300					else {
301						if (tt->logout < 0) {
302							tt->logout = -tt->logout;
303							printf("- %s", crmsg);
304						}
305						else {
306							tm = localtime(&tt->logout);
307							(void) strftime(ct, sizeof(ct), "%R", tm);
308							printf("- %s", ct);
309						}
310						delta = tt->logout - bp->ut_time;
311						if ( sflag ) {
312							printf("  (%8lu)\n",
313								delta);
314						} else {
315						    tm = gmtime(&delta);
316						    (void) strftime(ct, sizeof(ct),
317						     width >= 8 ? "%T" : "%R",
318						     tm);
319						    if (delta < 86400)
320							printf("  (%s)\n", ct);
321						    else
322							printf(" (%ld+%s)\n",
323							    delta / 86400,  ct);
324						}
325					}
326					LIST_REMOVE(tt, list);
327					free(tt);
328					if (maxrec != -1 && !--maxrec)
329						return;
330				} else {
331					tt->logout = bp->ut_time;
332				}
333			}
334		}
335	}
336	tm = localtime(&buf[0].ut_time);
337	(void) strftime(ct, sizeof(ct), "\nwtmp begins %c\n", tm);
338	printf("%s", ct);
339}
340
341/*
342 * want --
343 *	see if want this entry
344 */
345int
346want(bp)
347	struct utmp *bp;
348{
349	ARG *step;
350
351	if (!arglist)
352		return (YES);
353
354	for (step = arglist; step; step = step->next)
355		switch(step->type) {
356		case HOST_TYPE:
357			if (!strncasecmp(step->name, bp->ut_host, UT_HOSTSIZE))
358				return (YES);
359			break;
360		case TTY_TYPE:
361			if (!strncmp(step->name, bp->ut_line, UT_LINESIZE))
362				return (YES);
363			break;
364		case USER_TYPE:
365			if (!strncmp(step->name, bp->ut_name, UT_NAMESIZE))
366				return (YES);
367			break;
368	}
369	return (NO);
370}
371
372/*
373 * addarg --
374 *	add an entry to a linked list of arguments
375 */
376void
377addarg(type, arg)
378	int type;
379	char *arg;
380{
381	ARG *cur;
382
383	if (!(cur = (ARG *)malloc((u_int)sizeof(ARG))))
384		err(1, "malloc failure");
385	cur->next = arglist;
386	cur->type = type;
387	cur->name = arg;
388	arglist = cur;
389}
390
391/*
392 * hostconv --
393 *	convert the hostname to search pattern; if the supplied host name
394 *	has a domain attached that is the same as the current domain, rip
395 *	off the domain suffix since that's what login(1) does.
396 */
397void
398hostconv(arg)
399	char *arg;
400{
401	static int first = 1;
402	static char *hostdot, name[MAXHOSTNAMELEN];
403	char *argdot;
404
405	if (!(argdot = strchr(arg, '.')))
406		return;
407	if (first) {
408		first = 0;
409		if (gethostname(name, sizeof(name)))
410			err(1, "gethostname");
411		hostdot = strchr(name, '.');
412	}
413	if (hostdot && !strcasecmp(hostdot, argdot))
414		*argdot = '\0';
415}
416
417/*
418 * ttyconv --
419 *	convert tty to correct name.
420 */
421char *
422ttyconv(arg)
423	char *arg;
424{
425	char *mval;
426
427	/*
428	 * kludge -- we assume that all tty's end with
429	 * a two character suffix.
430	 */
431	if (strlen(arg) == 2) {
432		/* either 6 for "ttyxx" or 8 for "console" */
433		if (!(mval = malloc((u_int)8)))
434			err(1, "malloc failure");
435		if (!strcmp(arg, "co"))
436			(void)strcpy(mval, "console");
437		else {
438			(void)strcpy(mval, "tty");
439			(void)strcpy(mval + 3, arg);
440		}
441		return (mval);
442	}
443	if (!strncmp(arg, _PATH_DEV, sizeof(_PATH_DEV) - 1))
444		return (arg + 5);
445	return (arg);
446}
447
448/*
449 * onintr --
450 *	on interrupt, we inform the user how far we've gotten
451 */
452void
453onintr(signo)
454	int signo;
455{
456	char ct[80];
457	struct tm *tm;
458
459	tm = localtime(&buf[0].ut_time);
460	(void) strftime(ct, sizeof(ct),
461			d_first ? "%a %e %b %R" : "%a %b %e %R",
462			tm);
463	printf("\ninterrupted %s\n", ct);
464	if (signo == SIGINT)
465		exit(1);
466	(void)fflush(stdout);			/* fix required for rsh */
467}
468