src/who.c

   1 /* GNU's who.
   2    Copyright (C) 1992-2009 Free Software Foundation, Inc.
   3
   4    This program is free software: you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published by
   6    the Free Software Foundation, either version 3 of the License, or
   7    (at your option) any later version.
   8
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  16
  17 /* Written by jla; revised by djm; revised again by mstone */
  18
  19 /* Output format:
  20    name [state] line time [activity] [pid] [comment] [exit]
  21    state: -T
  22    name, line, time: not -q
  23    idle: -u
  24 */
  25
  26 #include <config.h>
  27 #include <getopt.h>
  28 #include <stdio.h>
  29
  30 #include <sys/types.h>
  31 #include "system.h"
  32
  33 #include "c-ctype.h"
  34 #include "canon-host.h"
  35 #include "readutmp.h"
  36 #include "error.h"
  37 #include "quote.h"
  38
  39 /* The official name of this program (e.g., no `g' prefix).  */
  40 #define PROGRAM_NAME "who"
  41
  42 #define AUTHORS \
  43   proper_name ("Joseph Arceneaux"), \
  44   proper_name ("David MacKenzie"), \
  45   proper_name ("Michael Stone")
  46
  47 #ifndef MAXHOSTNAMELEN
  48 # define MAXHOSTNAMELEN 64
  49 #endif
  50
  51 #ifdef RUN_LVL
  52 # define UT_TYPE_RUN_LVL(U) UT_TYPE_EQ (U, RUN_LVL)
  53 #else
  54 # define UT_TYPE_RUN_LVL(U) false
  55 #endif
  56
  57 #ifdef INIT_PROCESS
  58 # define UT_TYPE_INIT_PROCESS(U) UT_TYPE_EQ (U, INIT_PROCESS)
  59 #else
  60 # define UT_TYPE_INIT_PROCESS(U) false
  61 #endif
  62
  63 #ifdef LOGIN_PROCESS
  64 # define UT_TYPE_LOGIN_PROCESS(U) UT_TYPE_EQ (U, LOGIN_PROCESS)
  65 #else
  66 # define UT_TYPE_LOGIN_PROCESS(U) false
  67 #endif
  68
  69 #ifdef DEAD_PROCESS
  70 # define UT_TYPE_DEAD_PROCESS(U) UT_TYPE_EQ (U, DEAD_PROCESS)
  71 #else
  72 # define UT_TYPE_DEAD_PROCESS(U) false
  73 #endif
  74
  75 #ifdef NEW_TIME
  76 # define UT_TYPE_NEW_TIME(U) UT_TYPE_EQ (U, NEW_TIME)
  77 #else
  78 # define UT_TYPE_NEW_TIME(U) false
  79 #endif
  80
  81 #define IDLESTR_LEN 6
  82
  83 #if HAVE_STRUCT_XTMP_UT_PID
  84 # define PIDSTR_DECL_AND_INIT(Var, Utmp_ent) \
  85   char Var[INT_STRLEN_BOUND (Utmp_ent->ut_pid) + 1]; \
  86   sprintf (Var, "%ld", (long int) (Utmp_ent->ut_pid))
  87 #else
  88 # define PIDSTR_DECL_AND_INIT(Var, Utmp_ent) \
  89   const char *Var = ""
  90 #endif
  91
  92 #if HAVE_STRUCT_XTMP_UT_ID
  93 # define UT_ID(U) ((U)->ut_id)
  94 #else
  95 # define UT_ID(U) "??"
  96 #endif
  97
  98 char *ttyname (int);
  99
 100 /* If true, attempt to canonicalize hostnames via a DNS lookup. */
 101 static bool do_lookup;
 102
 103 /* If true, display only a list of usernames and count of
 104    the users logged on.
 105    Ignored for `who am i'.  */
 106 static bool short_list;
 107
 108 /* If true, display only name, line, and time fields.  */
 109 static bool short_output;
 110
 111 /* If true, display the hours:minutes since each user has touched
 112    the keyboard, or "." if within the last minute, or "old" if
 113    not within the last day.  */
 114 static bool include_idle;
 115
 116 /* If true, display a line at the top describing each field.  */
 117 static bool include_heading;
 118
 119 /* If true, display a `+' for each user if mesg y, a `-' if mesg n,
 120    or a `?' if their tty cannot be statted. */
 121 static bool include_mesg;
 122
 123 /* If true, display process termination & exit status.  */
 124 static bool include_exit;
 125
 126 /* If true, display the last boot time.  */
 127 static bool need_boottime;
 128
 129 /* If true, display dead processes.  */
 130 static bool need_deadprocs;
 131
 132 /* If true, display processes waiting for user login.  */
 133 static bool need_login;
 134
 135 /* If true, display processes started by init.  */
 136 static bool need_initspawn;
 137
 138 /* If true, display the last clock change.  */
 139 static bool need_clockchange;
 140
 141 /* If true, display the current runlevel.  */
 142 static bool need_runlevel;
 143
 144 /* If true, display user processes.  */
 145 static bool need_users;
 146
 147 /* If true, display info only for the controlling tty.  */
 148 static bool my_line_only;
 149
 150 /* The strftime format to use for login times, and its expected
 151    output width.  */
 152 static char const *time_format;
 153 static int time_format_width;
 154
 155 /* for long options with no corresponding short option, use enum */
 156 enum
 157 {
 158   LOOKUP_OPTION = CHAR_MAX + 1
 159 };
 160
 161 static struct option const longopts[] =
 162 {
 163   {"all", no_argument, NULL, 'a'},
 164   {"boot", no_argument, NULL, 'b'},
 165   {"count", no_argument, NULL, 'q'},
 166   {"dead", no_argument, NULL, 'd'},
 167   {"heading", no_argument, NULL, 'H'},
 168   {"login", no_argument, NULL, 'l'},
 169   {"lookup", no_argument, NULL, LOOKUP_OPTION},
 170   {"message", no_argument, NULL, 'T'},
 171   {"mesg", no_argument, NULL, 'T'},
 172   {"process", no_argument, NULL, 'p'},
 173   {"runlevel", no_argument, NULL, 'r'},
 174   {"short", no_argument, NULL, 's'},
 175   {"time", no_argument, NULL, 't'},
 176   {"users", no_argument, NULL, 'u'},
 177   {"writable", no_argument, NULL, 'T'},
 178   {GETOPT_HELP_OPTION_DECL},
 179   {GETOPT_VERSION_OPTION_DECL},
 180   {NULL, 0, NULL, 0}
 181 };
 182
 183 /* Return a string representing the time between WHEN and now.
 184    BOOTTIME is the time of last reboot.
 185    FIXME: locale? */
 186 static const char *
 187 idle_string (time_t when, time_t boottime)
 188 {
 189   static time_t now = TYPE_MINIMUM (time_t);
 190
 191   if (now == TYPE_MINIMUM (time_t))
 192     time (&now);
 193
 194   if (boottime < when && now - 24 * 60 * 60 < when && when <= now)
 195     {
 196       int seconds_idle = now - when;
 197       if (seconds_idle < 60)
 198         return "  .  ";
 199       else
 200         {
 201           static char idle_hhmm[IDLESTR_LEN];
 202           sprintf (idle_hhmm, "%02d:%02d",
 203                    seconds_idle / (60 * 60),
 204                    (seconds_idle % (60 * 60)) / 60);
 205           return idle_hhmm;
 206         }
 207     }
 208
 209   return _(" old ");
 210 }
 211
 212 /* Return a time string.  */
 213 static const char *
 214 time_string (const STRUCT_UTMP *utmp_ent)
 215 {
 216   static char buf[INT_STRLEN_BOUND (intmax_t) + sizeof "-%m-%d %H:%M"];
 217
 218   /* Don't take the address of UT_TIME_MEMBER directly.
 219      Ulrich Drepper wrote:
 220      ``... GNU libc (and perhaps other libcs as well) have extended
 221      utmp file formats which do not use a simple time_t ut_time field.
 222      In glibc, ut_time is a macro which selects for backward compatibility
 223      the tv_sec member of a struct timeval value.''  */
 224   time_t t = UT_TIME_MEMBER (utmp_ent);
 225   struct tm *tmp = localtime (&t);
 226
 227   if (tmp)
 228     {
 229       strftime (buf, sizeof buf, time_format, tmp);
 230       return buf;
 231     }
 232   else
 233     return timetostr (t, buf);
 234 }
 235
 236 /* Print formatted output line. Uses mostly arbitrary field sizes, probably
 237    will need tweaking if any of the localization stuff is done, or for 64 bit
 238    pids, etc. */
 239 static void
 240 print_line (int userlen, const char *user, const char state,
 241             int linelen, const char *line,
 242             const char *time_str, const char *idle, const char *pid,
 243             const char *comment, const char *exitstr)
 244 {
 245   static char mesg[3] = { ' ', 'x', '\0' };
 246   char *buf;
 247   char x_idle[1 + IDLESTR_LEN + 1];
 248   char x_pid[1 + INT_STRLEN_BOUND (pid_t) + 1];
 249   char *x_exitstr;
 250   int err;
 251
 252   mesg[1] = state;
 253
 254   if (include_idle && !short_output && strlen (idle) < sizeof x_idle - 1)
 255     sprintf (x_idle, " %-6s", idle);
 256   else
 257     *x_idle = '\0';
 258
 259   if (!short_output && strlen (pid) < sizeof x_pid - 1)
 260     sprintf (x_pid, " %10s", pid);
 261   else
 262     *x_pid = '\0';
 263
 264   x_exitstr = xmalloc (include_exit ? 1 + MAX (12, strlen (exitstr)) + 1 : 1);
 265   if (include_exit)
 266     sprintf (x_exitstr, " %-12s", exitstr);
 267   else
 268     *x_exitstr = '\0';
 269
 270   err = asprintf (&buf,
 271                   "%-8.*s"
 272                   "%s"
 273                   " %-12.*s"
 274                   " %-*s"
 275                   "%s"
 276                   "%s"
 277                   " %-8s"
 278                   "%s"
 279                   ,
 280                   userlen, user ? user : "   .",
 281                   include_mesg ? mesg : "",
 282                   linelen, line,
 283                   time_format_width,
 284                   time_str,
 285                   x_idle,
 286                   x_pid,
 287                   /* FIXME: it's not really clear whether the following
 288                      field should be in the short_output.  A strict reading
 289                      of SUSv2 would suggest not, but I haven't seen any
 290                      implementations that actually work that way... */
 291                   comment,
 292                   x_exitstr
 293                   );
 294   if (err == -1)
 295     xalloc_die ();
 296
 297   {
 298     /* Remove any trailing spaces.  */
 299     char *p = buf + strlen (buf);
 300     while (*--p == ' ')
 301       /* empty */;
 302     *(p + 1) = '\0';
 303   }
 304
 305   puts (buf);
 306   free (buf);
 307   free (x_exitstr);
 308 }
 309
 310 /* Send properly parsed USER_PROCESS info to print_line.  The most
 311    recent boot time is BOOTTIME. */
 312 static void
 313 print_user (const STRUCT_UTMP *utmp_ent, time_t boottime)
 314 {
 315   struct stat stats;
 316   time_t last_change;
 317   char mesg;
 318   char idlestr[IDLESTR_LEN + 1];
 319   static char *hoststr;
 320 #if HAVE_UT_HOST
 321   static size_t hostlen;
 322 #endif
 323
 324 #define DEV_DIR_WITH_TRAILING_SLASH "/dev/"
 325 #define DEV_DIR_LEN (sizeof (DEV_DIR_WITH_TRAILING_SLASH) - 1)
 326
 327   char line[sizeof (utmp_ent->ut_line) + DEV_DIR_LEN + 1];
 328   PIDSTR_DECL_AND_INIT (pidstr, utmp_ent);
 329
 330   /* Copy ut_line into LINE, prepending `/dev/' if ut_line is not
 331      already an absolute file name.  Some systems may put the full,
 332      absolute file name in ut_line.  */
 333   if (utmp_ent->ut_line[0] == '/')
 334     {
 335       strncpy (line, utmp_ent->ut_line, sizeof (utmp_ent->ut_line));
 336       line[sizeof (utmp_ent->ut_line)] = '\0';
 337     }
 338   else
 339     {
 340       strcpy (line, DEV_DIR_WITH_TRAILING_SLASH);
 341       strncpy (line + DEV_DIR_LEN, utmp_ent->ut_line,
 342                sizeof (utmp_ent->ut_line));
 343       line[DEV_DIR_LEN + sizeof (utmp_ent->ut_line)] = '\0';
 344     }
 345
 346   if (stat (line, &stats) == 0)
 347     {
 348       mesg = (stats.st_mode & S_IWGRP) ? '+' : '-';
 349       last_change = stats.st_atime;
 350     }
 351   else
 352     {
 353       mesg = '?';
 354       last_change = 0;
 355     }
 356
 357   if (last_change)
 358     sprintf (idlestr, "%.*s", IDLESTR_LEN, idle_string (last_change, boottime));
 359   else
 360     sprintf (idlestr, "  ?");
 361
 362 #if HAVE_UT_HOST
 363   if (utmp_ent->ut_host[0])
 364     {
 365       char ut_host[sizeof (utmp_ent->ut_host) + 1];
 366       char *host = NULL;
 367       char *display = NULL;
 368
 369       /* Copy the host name into UT_HOST, and ensure it's nul terminated. */
 370       strncpy (ut_host, utmp_ent->ut_host, sizeof (utmp_ent->ut_host));
 371       ut_host[sizeof (utmp_ent->ut_host)] = '\0';
 372
 373       /* Look for an X display.  */
 374       display = strchr (ut_host, ':');
 375       if (display)
 376         *display++ = '\0';
 377
 378       if (*ut_host && do_lookup)
 379         {
 380           /* See if we can canonicalize it.  */
 381           host = canon_host (ut_host);
 382         }
 383
 384       if (! host)
 385         host = ut_host;
 386
 387       if (display)
 388         {
 389           if (hostlen < strlen (host) + strlen (display) + 4)
 390             {
 391               hostlen = strlen (host) + strlen (display) + 4;
 392               hoststr = xrealloc (hoststr, hostlen);
 393             }
 394           sprintf (hoststr, "(%s:%s)", host, display);
 395         }
 396       else
 397         {
 398           if (hostlen < strlen (host) + 3)
 399             {
 400               hostlen = strlen (host) + 3;
 401               hoststr = xrealloc (hoststr, hostlen);
 402             }
 403           sprintf (hoststr, "(%s)", host);
 404         }
 405
 406       if (host != ut_host)
 407         free (host);
 408     }
 409   else
 410     {
 411       if (hostlen < 1)
 412         {
 413           hostlen = 1;
 414           hoststr = xrealloc (hoststr, hostlen);
 415         }
 416       *hoststr = '\0';
 417     }
 418 #endif
 419
 420   print_line (sizeof UT_USER (utmp_ent), UT_USER (utmp_ent), mesg,
 421               sizeof utmp_ent->ut_line, utmp_ent->ut_line,
 422               time_string (utmp_ent), idlestr, pidstr,
 423               hoststr ? hoststr : "", "");
 424 }
 425
 426 static void
 427 print_boottime (const STRUCT_UTMP *utmp_ent)
 428 {
 429   print_line (-1, "", ' ', -1, _("system boot"),
 430               time_string (utmp_ent), "", "", "", "");
 431 }
 432
 433 static char *
 434 make_id_equals_comment (STRUCT_UTMP const *utmp_ent)
 435 {
 436   char *comment = xmalloc (strlen (_("id=")) + sizeof UT_ID (utmp_ent) + 1);
 437
 438   strcpy (comment, _("id="));
 439   strncat (comment, UT_ID (utmp_ent), sizeof UT_ID (utmp_ent));
 440   return comment;
 441 }
 442
 443 static void
 444 print_deadprocs (const STRUCT_UTMP *utmp_ent)
 445 {
 446   static char *exitstr;
 447   char *comment = make_id_equals_comment (utmp_ent);
 448   PIDSTR_DECL_AND_INIT (pidstr, utmp_ent);
 449
 450   if (!exitstr)
 451     exitstr = xmalloc (strlen (_("term="))
 452                        + INT_STRLEN_BOUND (UT_EXIT_E_TERMINATION (utmp_ent)) + 1
 453                        + strlen (_("exit="))
 454                        + INT_STRLEN_BOUND (UT_EXIT_E_EXIT (utmp_ent))
 455                        + 1);
 456   sprintf (exitstr, "%s%d %s%d", _("term="), UT_EXIT_E_TERMINATION (utmp_ent),
 457            _("exit="), UT_EXIT_E_EXIT (utmp_ent));
 458
 459   /* FIXME: add idle time? */
 460
 461   print_line (-1, "", ' ', sizeof utmp_ent->ut_line, utmp_ent->ut_line,
 462               time_string (utmp_ent), "", pidstr, comment, exitstr);
 463   free (comment);
 464 }
 465
 466 static void
 467 print_login (const STRUCT_UTMP *utmp_ent)
 468 {
 469   char *comment = make_id_equals_comment (utmp_ent);
 470   PIDSTR_DECL_AND_INIT (pidstr, utmp_ent);
 471
 472   /* FIXME: add idle time? */
 473
 474   print_line (-1, _("LOGIN"), ' ', sizeof utmp_ent->ut_line, utmp_ent->ut_line,
 475               time_string (utmp_ent), "", pidstr, comment, "");
 476   free (comment);
 477 }
 478
 479 static void
 480 print_initspawn (const STRUCT_UTMP *utmp_ent)
 481 {
 482   char *comment = make_id_equals_comment (utmp_ent);
 483   PIDSTR_DECL_AND_INIT (pidstr, utmp_ent);
 484
 485   print_line (-1, "", ' ', sizeof utmp_ent->ut_line, utmp_ent->ut_line,
 486               time_string (utmp_ent), "", pidstr, comment, "");
 487   free (comment);
 488 }
 489
 490 static void
 491 print_clockchange (const STRUCT_UTMP *utmp_ent)
 492 {
 493   /* FIXME: handle NEW_TIME & OLD_TIME both */
 494   print_line (-1, "", ' ', -1, _("clock change"),
 495               time_string (utmp_ent), "", "", "", "");
 496 }
 497
 498 static void
 499 print_runlevel (const STRUCT_UTMP *utmp_ent)
 500 {
 501   static char *runlevline, *comment;
 502   unsigned char last = UT_PID (utmp_ent) / 256;
 503   unsigned char curr = UT_PID (utmp_ent) % 256;
 504
 505   if (!runlevline)
 506     runlevline = xmalloc (strlen (_("run-level")) + 3);
 507   sprintf (runlevline, "%s %c", _("run-level"), curr);
 508
 509   if (!comment)
 510     comment = xmalloc (strlen (_("last=")) + 2);
 511   sprintf (comment, "%s%c", _("last="), (last == 'N') ? 'S' : last);
 512
 513   print_line (-1, "", ' ', -1, runlevline, time_string (utmp_ent),
 514               "", "", c_isprint (last) ? comment : "", "");
 515
 516   return;
 517 }
 518
 519 /* Print the username of each valid entry and the number of valid entries
 520    in UTMP_BUF, which should have N elements. */
 521 static void
 522 list_entries_who (size_t n, const STRUCT_UTMP *utmp_buf)
 523 {
 524   unsigned long int entries = 0;
 525   char const *separator = "";
 526
 527   while (n--)
 528     {
 529       if (IS_USER_PROCESS (utmp_buf))
 530         {
 531           char *trimmed_name;
 532
 533           trimmed_name = extract_trimmed_name (utmp_buf);
 534
 535           printf ("%s%s", separator, trimmed_name);
 536           free (trimmed_name);
 537           separator = " ";
 538           entries++;
 539         }
 540       utmp_buf++;
 541     }
 542   printf (_("\n# users=%lu\n"), entries);
 543 }
 544
 545 static void
 546 print_heading (void)
 547 {
 548   print_line (-1, _("NAME"), ' ', -1, _("LINE"), _("TIME"), _("IDLE"),
 549               _("PID"), _("COMMENT"), _("EXIT"));
 550 }
 551
 552 /* Display UTMP_BUF, which should have N entries. */
 553 static void
 554 scan_entries (size_t n, const STRUCT_UTMP *utmp_buf)
 555 {
 556   char *ttyname_b IF_LINT ( = NULL);
 557   time_t boottime = TYPE_MINIMUM (time_t);
 558
 559   if (include_heading)
 560     print_heading ();
 561
 562   if (my_line_only)
 563     {
 564       ttyname_b = ttyname (STDIN_FILENO);
 565       if (!ttyname_b)
 566         return;
 567       if (strncmp (ttyname_b, DEV_DIR_WITH_TRAILING_SLASH, DEV_DIR_LEN) == 0)
 568         ttyname_b += DEV_DIR_LEN;       /* Discard /dev/ prefix.  */
 569     }
 570
 571   while (n--)
 572     {
 573       if (!my_line_only ||
 574           strncmp (ttyname_b, utmp_buf->ut_line,
 575                    sizeof (utmp_buf->ut_line)) == 0)
 576         {
 577           if (need_users && IS_USER_PROCESS (utmp_buf))
 578             print_user (utmp_buf, boottime);
 579           else if (need_runlevel && UT_TYPE_RUN_LVL (utmp_buf))
 580             print_runlevel (utmp_buf);
 581           else if (need_boottime && UT_TYPE_BOOT_TIME (utmp_buf))
 582             print_boottime (utmp_buf);
 583           /* I've never seen one of these, so I don't know what it should
 584              look like :^)
 585              FIXME: handle OLD_TIME also, perhaps show the delta? */
 586           else if (need_clockchange && UT_TYPE_NEW_TIME (utmp_buf))
 587             print_clockchange (utmp_buf);
 588           else if (need_initspawn && UT_TYPE_INIT_PROCESS (utmp_buf))
 589             print_initspawn (utmp_buf);
 590           else if (need_login && UT_TYPE_LOGIN_PROCESS (utmp_buf))
 591             print_login (utmp_buf);
 592           else if (need_deadprocs && UT_TYPE_DEAD_PROCESS (utmp_buf))
 593             print_deadprocs (utmp_buf);
 594         }
 595
 596       if (UT_TYPE_BOOT_TIME (utmp_buf))
 597         boottime = UT_TIME_MEMBER (utmp_buf);
 598
 599       utmp_buf++;
 600     }
 601 }
 602
 603 /* Display a list of who is on the system, according to utmp file FILENAME.
 604    Use read_utmp OPTIONS to read the file.  */
 605 static void
 606 who (const char *filename, int options)
 607 {
 608   size_t n_users;
 609   STRUCT_UTMP *utmp_buf;
 610
 611   if (read_utmp (filename, &n_users, &utmp_buf, options) != 0)
 612     error (EXIT_FAILURE, errno, "%s", filename);
 613
 614   if (short_list)
 615     list_entries_who (n_users, utmp_buf);
 616   else
 617     scan_entries (n_users, utmp_buf);
 618
 619   free (utmp_buf);
 620 }
 621
 622 void
 623 usage (int status)
 624 {
 625   if (status != EXIT_SUCCESS)
 626     fprintf (stderr, _("Try `%s --help' for more information.\n"),
 627              program_name);
 628   else
 629     {
 630       printf (_("Usage: %s [OPTION]... [ FILE | ARG1 ARG2 ]\n"), program_name);
 631       fputs (_("\
 632 Print information about users who are currently logged in.\n\
 633 "), stdout);
 634       fputs (_("\
 635 \n\
 636   -a, --all         same as -b -d --login -p -r -t -T -u\n\
 637   -b, --boot        time of last system boot\n\
 638   -d, --dead        print dead processes\n\
 639   -H, --heading     print line of column headings\n\
 640 "), stdout);
 641       fputs (_("\
 642   -l, --login       print system login processes\n\
 643 "), stdout);
 644       fputs (_("\
 645       --lookup      attempt to canonicalize hostnames via DNS\n\
 646   -m                only hostname and user associated with stdin\n\
 647   -p, --process     print active processes spawned by init\n\
 648 "), stdout);
 649       fputs (_("\
 650   -q, --count       all login names and number of users logged on\n\
 651   -r, --runlevel    print current runlevel\n\
 652   -s, --short       print only name, line, and time (default)\n\
 653   -t, --time        print last system clock change\n\
 654 "), stdout);
 655       fputs (_("\
 656   -T, -w, --mesg    add user's message status as +, - or ?\n\
 657   -u, --users       list users logged in\n\
 658       --message     same as -T\n\
 659       --writable    same as -T\n\
 660 "), stdout);
 661       fputs (HELP_OPTION_DESCRIPTION, stdout);
 662       fputs (VERSION_OPTION_DESCRIPTION, stdout);
 663       printf (_("\
 664 \n\
 665 If FILE is not specified, use %s.  %s as FILE is common.\n\
 666 If ARG1 ARG2 given, -m presumed: `am i' or `mom likes' are usual.\n\
 667 "), UTMP_FILE, WTMP_FILE);
 668       emit_bug_reporting_address ();
 669     }
 670   exit (status);
 671 }
 672
 673 int
 674 main (int argc, char **argv)
 675 {
 676   int optc;
 677   bool assumptions = true;
 678
 679   initialize_main (&argc, &argv);
 680   set_program_name (argv[0]);
 681   setlocale (LC_ALL, "");
 682   bindtextdomain (PACKAGE, LOCALEDIR);
 683   textdomain (PACKAGE);
 684
 685   atexit (close_stdout);
 686
 687   while ((optc = getopt_long (argc, argv, "abdlmpqrstuwHT", longopts, NULL))
 688          != -1)
 689     {
 690       switch (optc)
 691         {
 692         case 'a':
 693           need_boottime = true;
 694           need_deadprocs = true;
 695           need_login = true;
 696           need_initspawn = true;
 697           need_runlevel = true;
 698           need_clockchange = true;
 699           need_users = true;
 700           include_mesg = true;
 701           include_idle = true;
 702           include_exit = true;
 703           assumptions = false;
 704           break;
 705
 706         case 'b':
 707           need_boottime = true;
 708           assumptions = false;
 709           break;
 710
 711         case 'd':
 712           need_deadprocs = true;
 713           include_idle = true;
 714           include_exit = true;
 715           assumptions = false;
 716           break;
 717
 718         case 'H':
 719           include_heading = true;
 720           break;
 721
 722         case 'l':
 723           need_login = true;
 724           include_idle = true;
 725           assumptions = false;
 726           break;
 727
 728         case 'm':
 729           my_line_only = true;
 730           break;
 731
 732         case 'p':
 733           need_initspawn = true;
 734           assumptions = false;
 735           break;
 736
 737         case 'q':
 738           short_list = true;
 739           break;
 740
 741         case 'r':
 742           need_runlevel = true;
 743           include_idle = true;
 744           assumptions = false;
 745           break;
 746
 747         case 's':
 748           short_output = true;
 749           break;
 750
 751         case 't':
 752           need_clockchange = true;
 753           assumptions = false;
 754           break;
 755
 756         case 'T':
 757         case 'w':
 758           include_mesg = true;
 759           break;
 760
 761         case 'u':
 762           need_users = true;
 763           include_idle = true;
 764           assumptions = false;
 765           break;
 766
 767         case LOOKUP_OPTION:
 768           do_lookup = true;
 769           break;
 770
 771           case_GETOPT_HELP_CHAR;
 772
 773           case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
 774
 775         default:
 776           usage (EXIT_FAILURE);
 777         }
 778     }
 779
 780   if (assumptions)
 781     {
 782       need_users = true;
 783       short_output = true;
 784     }
 785
 786   if (include_exit)
 787     {
 788       short_output = false;
 789     }
 790
 791   if (hard_locale (LC_TIME))
 792     {
 793       time_format = "%Y-%m-%d %H:%M";
 794       time_format_width = 4 + 1 + 2 + 1 + 2 + 1 + 2 + 1 + 2;
 795     }
 796   else
 797     {
 798       time_format = "%b %e %H:%M";
 799       time_format_width = 3 + 1 + 2 + 1 + 2 + 1 + 2;
 800     }
 801
 802   switch (argc - optind)
 803     {
 804     case 2:                     /* who <blurf> <glop> */
 805       my_line_only = true;
 806       /* Fall through.  */
 807     case -1:
 808     case 0:                     /* who */
 809       who (UTMP_FILE, READ_UTMP_CHECK_PIDS);
 810       break;
 811
 812     case 1:                     /* who <utmp file> */
 813       who (argv[optind], 0);
 814       break;
 815
 816     default:                    /* lose */
 817       error (0, 0, _("extra operand %s"), quote (argv[optind + 2]));
 818       usage (EXIT_FAILURE);
 819     }
 820
 821   exit (EXIT_SUCCESS);
 822 }