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last.c revision 1.1 
      1 /*
      2  * Copyright (c) 1987 Regents of the University of California.
      3  * 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
     35 char copyright[] =
     36 "@(#) Copyright (c) 1987 Regents of the University of California.\n\
     37  All rights reserved.\n";
     38 #endif /* not lint */
     39 
     40 #ifndef lint
     41 static char sccsid[] = "@(#)last.c	5.18 (Berkeley) 3/1/91";
     42 #endif /* not lint */
     43 
     44 /*
     45  * last
     46  */
     47 #include <sys/param.h>
     48 #include <sys/stat.h>
     49 #include <sys/file.h>
     50 #include <signal.h>
     51 #include <time.h>
     52 #include <utmp.h>
     53 #include <stdio.h>
     54 #include <paths.h>
     55 
     56 #define	SECDAY	(24*60*60)			/* seconds in a day */
     57 #define	NO	0				/* false/no */
     58 #define	YES	1				/* true/yes */
     59 
     60 static struct utmp	buf[1024];		/* utmp read buffer */
     61 
     62 typedef struct arg {
     63 	char	*name;				/* argument */
     64 #define	HOST_TYPE	-2
     65 #define	TTY_TYPE	-3
     66 #define	USER_TYPE	-4
     67 	int	type;				/* type of arg */
     68 	struct arg	*next;			/* linked list pointer */
     69 } ARG;
     70 ARG	*arglist;				/* head of linked list */
     71 
     72 typedef struct ttytab {
     73 	long	logout;				/* log out time */
     74 	char	tty[UT_LINESIZE + 1];		/* terminal name */
     75 	struct ttytab	*next;			/* linked list pointer */
     76 } TTY;
     77 TTY	*ttylist;				/* head of linked list */
     78 
     79 static long	currentout,			/* current logout value */
     80 		maxrec;				/* records to display */
     81 static char	*file = _PATH_WTMP;		/* wtmp file */
     82 
     83 main(argc, argv)
     84 	int argc;
     85 	char **argv;
     86 {
     87 	extern int optind;
     88 	extern char *optarg;
     89 	int ch;
     90 	long atol();
     91 	char *p, *ttyconv();
     92 
     93 	maxrec = -1;
     94 	while ((ch = getopt(argc, argv, "0123456789f:h:t:")) != EOF)
     95 		switch((char)ch) {
     96 		case '0': case '1': case '2': case '3': case '4':
     97 		case '5': case '6': case '7': case '8': case '9':
     98 			/*
     99 			 * kludge: last was originally designed to take
    100 			 * a number after a dash.
    101 			 */
    102 			if (maxrec == -1) {
    103 				p = argv[optind - 1];
    104 				if (p[0] == '-' && p[1] == ch && !p[2])
    105 					maxrec = atol(++p);
    106 				else
    107 					maxrec = atol(argv[optind] + 1);
    108 				if (!maxrec)
    109 					exit(0);
    110 			}
    111 			break;
    112 		case 'f':
    113 			file = optarg;
    114 			break;
    115 		case 'h':
    116 			hostconv(optarg);
    117 			addarg(HOST_TYPE, optarg);
    118 			break;
    119 		case 't':
    120 			addarg(TTY_TYPE, ttyconv(optarg));
    121 			break;
    122 		case '?':
    123 		default:
    124 			fputs("usage: last [-#] [-f file] [-t tty] [-h hostname] [user ...]\n", stderr);
    125 			exit(1);
    126 		}
    127 
    128 	if (argc) {
    129 		setlinebuf(stdout);
    130 		for (argv += optind; *argv; ++argv) {
    131 #define	COMPATIBILITY
    132 #ifdef	COMPATIBILITY
    133 			/* code to allow "last p5" to work */
    134 			addarg(TTY_TYPE, ttyconv(*argv));
    135 #endif
    136 			addarg(USER_TYPE, *argv);
    137 		}
    138 	}
    139 	wtmp();
    140 	exit(0);
    141 }
    142 
    143 /*
    144  * wtmp --
    145  *	read through the wtmp file
    146  */
    147 wtmp()
    148 {
    149 	register struct utmp	*bp;		/* current structure */
    150 	register TTY	*T;			/* tty list entry */
    151 	struct stat	stb;			/* stat of file for size */
    152 	long	bl, delta,			/* time difference */
    153 		lseek(), time();
    154 	int	bytes, wfd;
    155 	char	*ct, *crmsg,
    156 		*asctime(), *ctime(), *strcpy();
    157 	TTY	*addtty();
    158 	void	onintr();
    159 
    160 	if ((wfd = open(file, O_RDONLY, 0)) < 0 || fstat(wfd, &stb) == -1) {
    161 		perror(file);
    162 		exit(1);
    163 	}
    164 	bl = (stb.st_size + sizeof(buf) - 1) / sizeof(buf);
    165 
    166 	(void)time(&buf[0].ut_time);
    167 	(void)signal(SIGINT, onintr);
    168 	(void)signal(SIGQUIT, onintr);
    169 
    170 	while (--bl >= 0) {
    171 		if (lseek(wfd, (long)(bl * sizeof(buf)), L_SET) == -1 ||
    172 		    (bytes = read(wfd, (char *)buf, sizeof(buf))) == -1) {
    173 			fprintf(stderr, "last: %s: ", file);
    174 			perror((char *)NULL);
    175 			exit(1);
    176 		}
    177 		for (bp = &buf[bytes / sizeof(buf[0]) - 1]; bp >= buf; --bp) {
    178 			/*
    179 			 * if the terminal line is '~', the machine stopped.
    180 			 * see utmp(5) for more info.
    181 			 */
    182 			if (bp->ut_line[0] == '~' && !bp->ut_line[1]) {
    183 				/* everybody just logged out */
    184 				for (T = ttylist; T; T = T->next)
    185 					T->logout = -bp->ut_time;
    186 				currentout = -bp->ut_time;
    187 				crmsg = strncmp(bp->ut_name, "shutdown",
    188 				    UT_NAMESIZE) ? "crash" : "shutdown";
    189 				if (want(bp, NO)) {
    190 					ct = ctime(&bp->ut_time);
    191 					printf("%-*.*s  %-*.*s %-*.*s %10.10s %5.5s \n", UT_NAMESIZE, UT_NAMESIZE, bp->ut_name, UT_LINESIZE, UT_LINESIZE, bp->ut_line, UT_HOSTSIZE, UT_HOSTSIZE, bp->ut_host, ct, ct + 11);
    192 					if (maxrec != -1 && !--maxrec)
    193 						return;
    194 				}
    195 				continue;
    196 			}
    197 			/*
    198 			 * if the line is '{' or '|', date got set; see
    199 			 * utmp(5) for more info.
    200 			 */
    201 			if ((bp->ut_line[0] == '{' || bp->ut_line[0] == '|')
    202 			    && !bp->ut_line[1]) {
    203 				if (want(bp, NO)) {
    204 					ct = ctime(&bp->ut_time);
    205 					printf("%-*.*s  %-*.*s %-*.*s %10.10s %5.5s \n", UT_NAMESIZE, UT_NAMESIZE, bp->ut_name, UT_LINESIZE, UT_LINESIZE, bp->ut_line, UT_HOSTSIZE, UT_HOSTSIZE, bp->ut_host, ct, ct + 11);
    206 					if (maxrec && !--maxrec)
    207 						return;
    208 				}
    209 				continue;
    210 			}
    211 			/* find associated tty */
    212 			for (T = ttylist;; T = T->next) {
    213 				if (!T) {
    214 					/* add new one */
    215 					T = addtty(bp->ut_line);
    216 					break;
    217 				}
    218 				if (!strncmp(T->tty, bp->ut_line, UT_LINESIZE))
    219 					break;
    220 			}
    221 			if (bp->ut_name[0] && want(bp, YES)) {
    222 				ct = ctime(&bp->ut_time);
    223 				printf("%-*.*s  %-*.*s %-*.*s %10.10s %5.5s ", UT_NAMESIZE, UT_NAMESIZE, bp->ut_name, UT_LINESIZE, UT_LINESIZE, bp->ut_line, UT_HOSTSIZE, UT_HOSTSIZE, bp->ut_host, ct, ct + 11);
    224 				if (!T->logout)
    225 					puts("  still logged in");
    226 				else {
    227 					if (T->logout < 0) {
    228 						T->logout = -T->logout;
    229 						printf("- %s", crmsg);
    230 					}
    231 					else
    232 						printf("- %5.5s", ctime(&T->logout)+11);
    233 					delta = T->logout - bp->ut_time;
    234 					if (delta < SECDAY)
    235 						printf("  (%5.5s)\n", asctime(gmtime(&delta))+11);
    236 					else
    237 						printf(" (%ld+%5.5s)\n", delta / SECDAY, asctime(gmtime(&delta))+11);
    238 				}
    239 				if (maxrec != -1 && !--maxrec)
    240 					return;
    241 			}
    242 			T->logout = bp->ut_time;
    243 		}
    244 	}
    245 	ct = ctime(&buf[0].ut_time);
    246 	printf("\nwtmp begins %10.10s %5.5s \n", ct, ct + 11);
    247 }
    248 
    249 /*
    250  * want --
    251  *	see if want this entry
    252  */
    253 want(bp, check)
    254 	register struct utmp *bp;
    255 	int check;
    256 {
    257 	register ARG *step;
    258 
    259 	if (check)
    260 		/*
    261 		 * when uucp and ftp log in over a network, the entry in
    262 		 * the utmp file is the name plus their process id.  See
    263 		 * etc/ftpd.c and usr.bin/uucp/uucpd.c for more information.
    264 		 */
    265 		if (!strncmp(bp->ut_line, "ftp", sizeof("ftp") - 1))
    266 			bp->ut_line[3] = '\0';
    267 		else if (!strncmp(bp->ut_line, "uucp", sizeof("uucp") - 1))
    268 			bp->ut_line[4] = '\0';
    269 	if (!arglist)
    270 		return(YES);
    271 
    272 	for (step = arglist; step; step = step->next)
    273 		switch(step->type) {
    274 		case HOST_TYPE:
    275 			if (!strncasecmp(step->name, bp->ut_host, UT_HOSTSIZE))
    276 				return(YES);
    277 			break;
    278 		case TTY_TYPE:
    279 			if (!strncmp(step->name, bp->ut_line, UT_LINESIZE))
    280 				return(YES);
    281 			break;
    282 		case USER_TYPE:
    283 			if (!strncmp(step->name, bp->ut_name, UT_NAMESIZE))
    284 				return(YES);
    285 			break;
    286 	}
    287 	return(NO);
    288 }
    289 
    290 /*
    291  * addarg --
    292  *	add an entry to a linked list of arguments
    293  */
    294 addarg(type, arg)
    295 	int type;
    296 	char *arg;
    297 {
    298 	register ARG *cur;
    299 	char *malloc();
    300 
    301 	if (!(cur = (ARG *)malloc((u_int)sizeof(ARG)))) {
    302 		fputs("last: malloc failure.\n", stderr);
    303 		exit(1);
    304 	}
    305 	cur->next = arglist;
    306 	cur->type = type;
    307 	cur->name = arg;
    308 	arglist = cur;
    309 }
    310 
    311 /*
    312  * addtty --
    313  *	add an entry to a linked list of ttys
    314  */
    315 TTY *
    316 addtty(ttyname)
    317 	char *ttyname;
    318 {
    319 	register TTY *cur;
    320 	char *malloc();
    321 
    322 	if (!(cur = (TTY *)malloc((u_int)sizeof(TTY)))) {
    323 		fputs("last: malloc failure.\n", stderr);
    324 		exit(1);
    325 	}
    326 	cur->next = ttylist;
    327 	cur->logout = currentout;
    328 	bcopy(ttyname, cur->tty, UT_LINESIZE);
    329 	return(ttylist = cur);
    330 }
    331 
    332 /*
    333  * hostconv --
    334  *	convert the hostname to search pattern; if the supplied host name
    335  *	has a domain attached that is the same as the current domain, rip
    336  *	off the domain suffix since that's what login(1) does.
    337  */
    338 hostconv(arg)
    339 	char *arg;
    340 {
    341 	static int first = 1;
    342 	static char *hostdot, name[MAXHOSTNAMELEN];
    343 	char *argdot, *index();
    344 
    345 	if (!(argdot = index(arg, '.')))
    346 		return;
    347 	if (first) {
    348 		first = 0;
    349 		if (gethostname(name, sizeof(name))) {
    350 			perror("last: gethostname");
    351 			exit(1);
    352 		}
    353 		hostdot = index(name, '.');
    354 	}
    355 	if (hostdot && !strcasecmp(hostdot, argdot))
    356 		*argdot = '\0';
    357 }
    358 
    359 /*
    360  * ttyconv --
    361  *	convert tty to correct name.
    362  */
    363 char *
    364 ttyconv(arg)
    365 	char *arg;
    366 {
    367 	char *mval, *malloc(), *strcpy();
    368 
    369 	/*
    370 	 * kludge -- we assume that all tty's end with
    371 	 * a two character suffix.
    372 	 */
    373 	if (strlen(arg) == 2) {
    374 		/* either 6 for "ttyxx" or 8 for "console" */
    375 		if (!(mval = malloc((u_int)8))) {
    376 			fputs("last: malloc failure.\n", stderr);
    377 			exit(1);
    378 		}
    379 		if (!strcmp(arg, "co"))
    380 			(void)strcpy(mval, "console");
    381 		else {
    382 			(void)strcpy(mval, "tty");
    383 			(void)strcpy(mval + 3, arg);
    384 		}
    385 		return(mval);
    386 	}
    387 	if (!strncmp(arg, _PATH_DEV, sizeof(_PATH_DEV) - 1))
    388 		return(arg + 5);
    389 	return(arg);
    390 }
    391 
    392 /*
    393  * onintr --
    394  *	on interrupt, we inform the user how far we've gotten
    395  */
    396 void
    397 onintr(signo)
    398 	int signo;
    399 {
    400 	char *ct, *ctime();
    401 
    402 	ct = ctime(&buf[0].ut_time);
    403 	printf("\ninterrupted %10.10s %5.5s \n", ct, ct + 11);
    404 	if (signo == SIGINT)
    405 		exit(1);
    406 	(void)fflush(stdout);			/* fix required for rsh */
    407 }
    408