Home | History | Annotate | Line # | Download | only in who
who.c revision 1.6 
      1 /*	$NetBSD: who.c,v 1.6 1997/10/20 03:20:29 lukem Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1989, 1993
      5  *	The Regents of the University of California.  All rights reserved.
      6  *
      7  * This code is derived from software contributed to Berkeley by
      8  * Michael Fischbein.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  * 3. All advertising materials mentioning features or use of this software
     19  *    must display the following acknowledgement:
     20  *	This product includes software developed by the University of
     21  *	California, Berkeley and its contributors.
     22  * 4. Neither the name of the University nor the names of its contributors
     23  *    may be used to endorse or promote products derived from this software
     24  *    without specific prior written permission.
     25  *
     26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     36  * SUCH DAMAGE.
     37  */
     38 
     39 #include <sys/cdefs.h>
     40 #ifndef lint
     41 __COPYRIGHT(
     42 "@(#) Copyright (c) 1989, 1993\n\
     43 	The Regents of the University of California.  All rights reserved.\n");
     44 #endif /* not lint */
     45 
     46 #ifndef lint
     47 #if 0
     48 static char sccsid[] = "@(#)who.c	8.1 (Berkeley) 6/6/93";
     49 #endif
     50 __RCSID("$NetBSD: who.c,v 1.6 1997/10/20 03:20:29 lukem Exp $");
     51 #endif /* not lint */
     52 
     53 #include <sys/types.h>
     54 #include <sys/stat.h>
     55 #include <err.h>
     56 #include <locale.h>
     57 #include <pwd.h>
     58 #include <stdio.h>
     59 #include <stdlib.h>
     60 #include <string.h>
     61 #include <time.h>
     62 #include <unistd.h>
     63 #include <utmp.h>
     64 
     65 void output __P((struct utmp *));
     66 void output_labels __P((void));
     67 void who_am_i __P((FILE *));
     68 FILE *file __P((char *));
     69 void usage __P((void));
     70 
     71 int show_term;			/* show term state */
     72 int show_idle;			/* show idle time */
     73 
     74 int main __P((int, char **));
     75 
     76 int
     77 main(argc, argv)
     78 	int argc;
     79 	char **argv;
     80 {
     81 	struct utmp usr;
     82 	FILE *ufp;
     83 	int c, only_current_term, show_labels;
     84 
     85 	setlocale(LC_ALL, "");
     86 
     87 	only_current_term = show_term = show_idle = show_labels = 0;
     88 	while ((c = getopt(argc, argv, "mTuH")) != -1) {
     89 		switch (c) {
     90 		case 'm':
     91 			only_current_term = 1;
     92 			break;
     93 		case 'T':
     94 			show_term = 1;
     95 			break;
     96 		case 'u':
     97 			show_idle = 1;
     98 			break;
     99 		case 'H':
    100 			show_labels = 1;
    101 			break;
    102 		default:
    103 			usage();
    104 			/* NOTREACHED */
    105 		}
    106 	}
    107 	argc -= optind;
    108 	argv += optind;
    109 
    110 	if (chdir("/dev")) {
    111 		err(1, "cannot change directory to /dev");
    112 		/* NOTREACHED */
    113 	}
    114 
    115 	if (show_labels)
    116 		output_labels();
    117 
    118 	switch (argc) {
    119 	case 0:					/* who */
    120 		ufp = file(_PATH_UTMP);
    121 
    122 		if (only_current_term) {
    123 			who_am_i(ufp);
    124 		} else {
    125 			/* only entries with both name and line fields */
    126 			while (fread((char *)&usr, sizeof(usr), 1, ufp) == 1)
    127 				if (*usr.ut_name && *usr.ut_line)
    128 					output(&usr);
    129 		}
    130 		break;
    131 	case 1:					/* who utmp_file */
    132 		ufp = file(*argv);
    133 
    134 		if (only_current_term) {
    135 			who_am_i(ufp);
    136 		} else {
    137 			/* all entries */
    138 			while (fread((char *)&usr, sizeof(usr), 1, ufp) == 1)
    139 				output(&usr);
    140 		}
    141 		break;
    142 	case 2:					/* who am i */
    143 		ufp = file(_PATH_UTMP);
    144 		who_am_i(ufp);
    145 		break;
    146 	default:
    147 		usage();
    148 		/* NOTREACHED */
    149 	}
    150 	exit(0);
    151 }
    152 
    153 void
    154 who_am_i(ufp)
    155 	FILE *ufp;
    156 {
    157 	struct utmp usr;
    158 	struct passwd *pw;
    159 	char *p;
    160 	char *t;
    161 
    162 	/* search through the utmp and find an entry for this tty */
    163 	if ((p = ttyname(0)) != NULL) {
    164 		/* strip any directory component */
    165 		if ((t = strrchr(p, '/')) != NULL)
    166 			p = t + 1;
    167 		while (fread((char *)&usr, sizeof(usr), 1, ufp) == 1)
    168 			if (usr.ut_name && !strcmp(usr.ut_line, p)) {
    169 				output(&usr);
    170 				return;
    171 			}
    172 		/* well, at least we know what the tty is */
    173 		(void)strncpy(usr.ut_line, p, UT_LINESIZE);
    174 	} else
    175 		(void)strcpy(usr.ut_line, "tty??");
    176 
    177 	pw = getpwuid(getuid());
    178 	(void)strncpy(usr.ut_name, pw ? pw->pw_name : "?", UT_NAMESIZE);
    179 	(void)time(&usr.ut_time);
    180 	*usr.ut_host = '\0';
    181 	output(&usr);
    182 }
    183 
    184 void
    185 output(up)
    186 	struct utmp *up;
    187 {
    188 	struct stat sb;
    189 	char line[sizeof (up->ut_line) + 1];
    190 	char state;
    191 	static time_t now = 0;
    192 	time_t idle;
    193 
    194 	state = '?';
    195 	idle = 0;
    196 
    197 	if (show_term || show_idle) {
    198 		if (now == 0)
    199 			time(&now);
    200 
    201 		strncpy(line, up->ut_line, sizeof (up->ut_line));
    202 		line[sizeof (up->ut_line)] = '\0';
    203 
    204 		if (stat(line, &sb) == 0) {
    205 			state = (sb.st_mode & 020) ? '+' : '-';
    206 			idle = now - sb.st_atime;
    207 		}
    208 
    209 	}
    210 
    211 	(void)printf("%-*.*s ", UT_NAMESIZE, UT_NAMESIZE, up->ut_name);
    212 
    213 	if (show_term) {
    214 		(void)printf("%c ", state);
    215 	}
    216 
    217 	(void)printf("%-*.*s ", UT_LINESIZE, UT_LINESIZE, up->ut_line);
    218 	(void)printf("%.12s ", ctime(&up->ut_time) + 4);
    219 
    220 	if (show_idle) {
    221 		if (idle < 60)
    222 			(void)printf("  .   ");
    223 		else if (idle < (24 * 60 * 60))
    224 			(void)printf("%02ld:%02ld ",
    225 				     (long)(idle / (60 * 60)),
    226 				     (long)(idle % (60 * 60)) / 60);
    227 		else
    228 			(void)printf(" old  ");
    229 	}
    230 
    231 	if (*up->ut_host)
    232 		printf("\t(%.*s)", UT_HOSTSIZE, up->ut_host);
    233 	(void)putchar('\n');
    234 }
    235 
    236 void
    237 output_labels()
    238 {
    239 	(void)printf("%-*.*s ", UT_NAMESIZE, UT_NAMESIZE, "USER");
    240 
    241 	if (show_term)
    242 		(void)printf("S ");
    243 
    244 	(void)printf("%-*.*s ", UT_LINESIZE, UT_LINESIZE, "LINE");
    245 	(void)printf("WHEN         ");
    246 
    247 	if (show_idle)
    248 		(void)printf("IDLE  ");
    249 
    250 	(void)printf("\t%.*s", UT_HOSTSIZE, "FROM");
    251 
    252 	(void)putchar('\n');
    253 }
    254 
    255 FILE *
    256 file(name)
    257 	char *name;
    258 {
    259 	FILE *ufp;
    260 
    261 	if (!(ufp = fopen(name, "r"))) {
    262 		err(1, "%s", name);
    263 		/* NOTREACHED */
    264 	}
    265 	return (ufp);
    266 }
    267 
    268 void
    269 usage()
    270 {
    271 	(void)fprintf(stderr, "usage: who [-mTuH] [ file ]\n       who am i\n");
    272 	exit(1);
    273 }
    274