last.c revision 9987 
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 <unistd.h>
56#include <utmp.h>
57
58#define	NO	0				/* false/no */
59#define	YES	1				/* true/yes */
60
61static struct utmp	buf[1024];		/* utmp read buffer */
62
63typedef struct arg {
64	char	*name;				/* argument */
65#define	HOST_TYPE	-2
66#define	TTY_TYPE	-3
67#define	USER_TYPE	-4
68	int	type;				/* type of arg */
69	struct arg	*next;			/* linked list pointer */
70} ARG;
71ARG	*arglist;				/* head of linked list */
72
73typedef struct ttytab {
74	long	logout;				/* log out time */
75	char	tty[UT_LINESIZE + 1];		/* terminal name */
76	struct ttytab	*next;			/* linked list pointer */
77} TTY;
78TTY	*ttylist;				/* head of linked list */
79
80static long	currentout,			/* current logout value */
81		maxrec;				/* records to display */
82static char	*file = _PATH_WTMP;		/* wtmp file */
83
84void	 addarg __P((int, char *));
85TTY	*addtty __P((char *));
86void	 hostconv __P((char *));
87void	 onintr __P((int));
88char	*ttyconv __P((char *));
89int	 want __P((struct utmp *, int));
90void	 wtmp __P((void));
91
92int
93main(argc, argv)
94	int argc;
95	char *argv[];
96{
97	extern int optind;
98	extern char *optarg;
99	int ch;
100	char *p;
101
102	maxrec = -1;
103	while ((ch = getopt(argc, argv, "0123456789f:h:t:")) != EOF)
104		switch (ch) {
105		case '0': case '1': case '2': case '3': case '4':
106		case '5': case '6': case '7': case '8': case '9':
107			/*
108			 * kludge: last was originally designed to take
109			 * a number after a dash.
110			 */
111			if (maxrec == -1) {
112				p = argv[optind - 1];
113				if (p[0] == '-' && p[1] == ch && !p[2])
114					maxrec = atol(++p);
115				else
116					maxrec = atol(argv[optind] + 1);
117				if (!maxrec)
118					exit(0);
119			}
120			break;
121		case 'f':
122			file = optarg;
123			break;
124		case 'h':
125			hostconv(optarg);
126			addarg(HOST_TYPE, optarg);
127			break;
128		case 't':
129			addarg(TTY_TYPE, ttyconv(optarg));
130			break;
131		case '?':
132		default:
133			(void)fprintf(stderr,
134	"usage: last [-#] [-f file] [-t tty] [-h hostname] [user ...]\n");
135			exit(1);
136		}
137
138	if (argc) {
139		setlinebuf(stdout);
140		for (argv += optind; *argv; ++argv) {
141#define	COMPATIBILITY
142#ifdef	COMPATIBILITY
143			/* code to allow "last p5" to work */
144			addarg(TTY_TYPE, ttyconv(*argv));
145#endif
146			addarg(USER_TYPE, *argv);
147		}
148	}
149	wtmp();
150	exit(0);
151}
152
153/*
154 * wtmp --
155 *	read through the wtmp file
156 */
157void
158wtmp()
159{
160	struct utmp	*bp;			/* current structure */
161	TTY	*T;				/* tty list entry */
162	struct stat	stb;			/* stat of file for size */
163	long	bl, delta;			/* time difference */
164	int	bytes, wfd;
165	char	*ct, *crmsg;
166
167	if ((wfd = open(file, O_RDONLY, 0)) < 0 || fstat(wfd, &stb) == -1)
168		err(1, "%s", file);
169	bl = (stb.st_size + sizeof(buf) - 1) / sizeof(buf);
170
171	(void)time(&buf[0].ut_time);
172	(void)signal(SIGINT, onintr);
173	(void)signal(SIGQUIT, onintr);
174
175	while (--bl >= 0) {
176		if (lseek(wfd, (off_t)(bl * sizeof(buf)), L_SET) == -1 ||
177		    (bytes = read(wfd, buf, sizeof(buf))) == -1)
178			err(1, "%s", file);
179		for (bp = &buf[bytes / sizeof(buf[0]) - 1]; bp >= buf; --bp) {
180			/*
181			 * if the terminal line is '~', the machine stopped.
182			 * see utmp(5) for more info.
183			 */
184			if (bp->ut_line[0] == '~' && !bp->ut_line[1]) {
185				/* everybody just logged out */
186				for (T = ttylist; T; T = T->next)
187					T->logout = -bp->ut_time;
188				currentout = -bp->ut_time;
189				crmsg = strncmp(bp->ut_name, "shutdown",
190				    UT_NAMESIZE) ? "crash" : "shutdown";
191				if (want(bp, NO)) {
192					ct = ctime(&bp->ut_time);
193				printf("%-*.*s  %-*.*s %-*.*s %10.10s %5.5s \n",
194					    UT_NAMESIZE, UT_NAMESIZE,
195					    bp->ut_name, UT_LINESIZE,
196					    UT_LINESIZE, bp->ut_line,
197					    UT_HOSTSIZE, UT_HOSTSIZE,
198					    bp->ut_host, ct, ct + 11);
199					if (maxrec != -1 && !--maxrec)
200						return;
201				}
202				continue;
203			}
204			/*
205			 * if the line is '{' or '|', date got set; see
206			 * utmp(5) for more info.
207			 */
208			if ((bp->ut_line[0] == '{' || bp->ut_line[0] == '|')
209			    && !bp->ut_line[1]) {
210				if (want(bp, NO)) {
211					ct = ctime(&bp->ut_time);
212				printf("%-*.*s  %-*.*s %-*.*s %10.10s %5.5s \n",
213				    UT_NAMESIZE, UT_NAMESIZE, bp->ut_name,
214				    UT_LINESIZE, UT_LINESIZE, bp->ut_line,
215				    UT_HOSTSIZE, UT_HOSTSIZE, bp->ut_host,
216				    ct, ct + 11);
217					if (maxrec && !--maxrec)
218						return;
219				}
220				continue;
221			}
222			/* find associated tty */
223			for (T = ttylist;; T = T->next) {
224				if (!T) {
225					/* add new one */
226					T = addtty(bp->ut_line);
227					break;
228				}
229				if (!strncmp(T->tty, bp->ut_line, UT_LINESIZE))
230					break;
231			}
232			if (bp->ut_name[0] && want(bp, YES)) {
233				ct = ctime(&bp->ut_time);
234				printf("%-*.*s  %-*.*s %-*.*s %10.10s %5.5s ",
235				UT_NAMESIZE, UT_NAMESIZE, bp->ut_name,
236				UT_LINESIZE, UT_LINESIZE, bp->ut_line,
237				UT_HOSTSIZE, UT_HOSTSIZE, bp->ut_host,
238				ct, ct + 11);
239				if (!T->logout)
240					puts("  still logged in");
241				else {
242					if (T->logout < 0) {
243						T->logout = -T->logout;
244						printf("- %s", crmsg);
245					}
246					else
247						printf("- %5.5s",
248						    ctime(&T->logout)+11);
249					delta = T->logout - bp->ut_time;
250					if (delta < 86400)
251						printf("  (%5.5s)\n",
252						    asctime(gmtime(&delta))+11);
253					else
254						printf(" (%ld+%5.5s)\n",
255						    delta / 86400,
256						    asctime(gmtime(&delta))+11);
257				}
258				if (maxrec != -1 && !--maxrec)
259					return;
260			}
261			T->logout = bp->ut_time;
262		}
263	}
264	ct = ctime(&buf[0].ut_time);
265	printf("\nwtmp begins %10.10s %5.5s \n", ct, ct + 11);
266}
267
268/*
269 * want --
270 *	see if want this entry
271 */
272int
273want(bp, check)
274	struct utmp *bp;
275	int check;
276{
277	ARG *step;
278
279	if (check)
280		/*
281		 * when uucp and ftp log in over a network, the entry in
282		 * the utmp file is the name plus their process id.  See
283		 * etc/ftpd.c and usr.bin/uucp/uucpd.c for more information.
284		 */
285		if (!strncmp(bp->ut_line, "ftp", sizeof("ftp") - 1))
286			bp->ut_line[3] = '\0';
287		else if (!strncmp(bp->ut_line, "uucp", sizeof("uucp") - 1))
288			bp->ut_line[4] = '\0';
289	if (!arglist)
290		return (YES);
291
292	for (step = arglist; step; step = step->next)
293		switch(step->type) {
294		case HOST_TYPE:
295			if (!strncasecmp(step->name, bp->ut_host, UT_HOSTSIZE))
296				return (YES);
297			break;
298		case TTY_TYPE:
299			if (!strncmp(step->name, bp->ut_line, UT_LINESIZE))
300				return (YES);
301			break;
302		case USER_TYPE:
303			if (!strncmp(step->name, bp->ut_name, UT_NAMESIZE))
304				return (YES);
305			break;
306	}
307	return (NO);
308}
309
310/*
311 * addarg --
312 *	add an entry to a linked list of arguments
313 */
314void
315addarg(type, arg)
316	int type;
317	char *arg;
318{
319	ARG *cur;
320
321	if (!(cur = (ARG *)malloc((u_int)sizeof(ARG))))
322		err(1, "malloc failure");
323	cur->next = arglist;
324	cur->type = type;
325	cur->name = arg;
326	arglist = cur;
327}
328
329/*
330 * addtty --
331 *	add an entry to a linked list of ttys
332 */
333TTY *
334addtty(ttyname)
335	char *ttyname;
336{
337	TTY *cur;
338
339	if (!(cur = (TTY *)malloc((u_int)sizeof(TTY))))
340		err(1, "malloc failure");
341	cur->next = ttylist;
342	cur->logout = currentout;
343	memmove(cur->tty, ttyname, UT_LINESIZE);
344	return (ttylist = cur);
345}
346
347/*
348 * hostconv --
349 *	convert the hostname to search pattern; if the supplied host name
350 *	has a domain attached that is the same as the current domain, rip
351 *	off the domain suffix since that's what login(1) does.
352 */
353void
354hostconv(arg)
355	char *arg;
356{
357	static int first = 1;
358	static char *hostdot, name[MAXHOSTNAMELEN];
359	char *argdot;
360
361	if (!(argdot = strchr(arg, '.')))
362		return;
363	if (first) {
364		first = 0;
365		if (gethostname(name, sizeof(name)))
366			err(1, "gethostname");
367		hostdot = strchr(name, '.');
368	}
369	if (hostdot && !strcasecmp(hostdot, argdot))
370		*argdot = '\0';
371}
372
373/*
374 * ttyconv --
375 *	convert tty to correct name.
376 */
377char *
378ttyconv(arg)
379	char *arg;
380{
381	char *mval;
382
383	/*
384	 * kludge -- we assume that all tty's end with
385	 * a two character suffix.
386	 */
387	if (strlen(arg) == 2) {
388		/* either 6 for "ttyxx" or 8 for "console" */
389		if (!(mval = malloc((u_int)8)))
390			err(1, "malloc failure");
391		if (!strcmp(arg, "co"))
392			(void)strcpy(mval, "console");
393		else {
394			(void)strcpy(mval, "tty");
395			(void)strcpy(mval + 3, arg);
396		}
397		return (mval);
398	}
399	if (!strncmp(arg, _PATH_DEV, sizeof(_PATH_DEV) - 1))
400		return (arg + 5);
401	return (arg);
402}
403
404/*
405 * onintr --
406 *	on interrupt, we inform the user how far we've gotten
407 */
408void
409onintr(signo)
410	int signo;
411{
412	char *ct;
413
414	ct = ctime(&buf[0].ut_time);
415	printf("\ninterrupted %10.10s %5.5s \n", ct, ct + 11);
416	if (signo == SIGINT)
417		exit(1);
418	(void)fflush(stdout);			/* fix required for rsh */
419}
420