who/who.c

   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 }