src/who.c

   1 /* GNU's who.
   2    Copyright (C) 1992-2007 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 2, or (at your option)
   7    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, write to the Free Software Foundation,
  16    Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
  17
  18 /* Written by jla; revised by djm; revised again by mstone */
  19
  20 /* Output format:
  21    name [state] line time [activity] [pid] [comment] [exit]
  22    state: -T
  23    name, line, time: not -q
  24    idle: -u
  25 */
  26
  27 #include <config.h>
  28 #include <getopt.h>
  29 #include <stdio.h>
  30
  31 #include <sys/types.h>
  32 #include "system.h"
  33
  34 #include "canon-host.h"
  35 #include "readutmp.h"
  36 #include "error.h"
  37 #include "hard-locale.h"
  38 #include "inttostr.h"
  39 #include "quote.h"
  40
  41 /* The official name of this program (e.g., no `g' prefix).  */
  42 #define PROGRAM_NAME "who"
  43
  44 #define AUTHORS "Joseph Arceneaux", "David MacKenzie", "Michael Stone"
  45
  46 #ifndef MAXHOSTNAMELEN
  47 # define MAXHOSTNAMELEN 64
  48 #endif
  49
  50 #ifdef RUN_LVL
  51 # define UT_TYPE_RUN_LVL(U) UT_TYPE_EQ (U, RUN_LVL)
  52 #else
  53 # define UT_TYPE_RUN_LVL(U) false
  54 #endif
  55
  56 #ifdef INIT_PROCESS
  57 # define UT_TYPE_INIT_PROCESS(U) UT_TYPE_EQ (U, INIT_PROCESS)
  58 #else
  59 # define UT_TYPE_INIT_PROCESS(U) false
  60 #endif
  61
  62 #ifdef LOGIN_PROCESS
  63 # define UT_TYPE_LOGIN_PROCESS(U) UT_TYPE_EQ (U, LOGIN_PROCESS)
  64 #else
  65 # define UT_TYPE_LOGIN_PROCESS(U) false
  66 #endif
  67
  68 #ifdef DEAD_PROCESS
  69 # define UT_TYPE_DEAD_PROCESS(U) UT_TYPE_EQ (U, DEAD_PROCESS)
  70 #else
  71 # define UT_TYPE_DEAD_PROCESS(U) false
  72 #endif
  73
  74 #ifdef NEW_TIME
  75 # define UT_TYPE_NEW_TIME(U) UT_TYPE_EQ (U, NEW_TIME)
  76 #else
  77 # define UT_TYPE_NEW_TIME(U) false
  78 #endif
  79
  80 #define IDLESTR_LEN 6
  81
  82 #if HAVE_STRUCT_XTMP_UT_PID
  83 # define PIDSTR_DECL_AND_INIT(Var, Utmp_ent) \
  84   char Var[INT_STRLEN_BOUND (Utmp_ent->ut_pid) + 1]; \
  85   sprintf (Var, "%ld", (long int) (Utmp_ent->ut_pid))
  86 #else
  87 # define PIDSTR_DECL_AND_INIT(Var, Utmp_ent) \
  88   const char *Var = ""
  89 #endif
  90
  91 #if HAVE_STRUCT_XTMP_UT_ID
  92 # define UT_ID(U) ((U)->ut_id)
  93 #else
  94 # define UT_ID(U) "??"
  95 #endif
  96
  97 char *ttyname ();
  98
  99 /* The name this program was run with. */
 100 char *program_name;
 101
 102 /* If true, attempt to canonicalize hostnames via a DNS lookup. */
 103 static bool do_lookup;
 104
 105 /* If true, display only a list of usernames and count of
 106    the users logged on.
 107    Ignored for `who am i'.  */
 108 static bool short_list;
 109
 110 /* If true, display only name, line, and time fields.  */
 111 static bool short_output;
 112
 113 /* If true, display the hours:minutes since each user has touched
 114    the keyboard, or "." if within the last minute, or "old" if
 115    not within the last day.  */
 116 static bool include_idle;
 117
 118 /* If true, display a line at the top describing each field.  */
 119 static bool include_heading;
 120
 121 /* If true, display a `+' for each user if mesg y, a `-' if mesg n,
 122    or a `?' if their tty cannot be statted. */
 123 static bool include_mesg;
 124
 125 /* If true, display process termination & exit status.  */
 126 static bool include_exit;
 127
 128 /* If true, display the last boot time.  */
 129 static bool need_boottime;
 130
 131 /* If true, display dead processes.  */
 132 static bool need_deadprocs;
 133
 134 /* If true, display processes waiting for user login.  */
 135 static bool need_login;
 136
 137 /* If true, display processes started by init.  */
 138 static bool need_initspawn;
 139
 140 /* If true, display the last clock change.  */
 141 static bool need_clockchange;
 142
 143 /* If true, display the current runlevel.  */
 144 static bool need_runlevel;
 145
 146 /* If true, display user processes.  */
 147 static bool need_users;
 148
 149 /* If true, display info only for the controlling tty.  */
 150 static bool my_line_only;
 151
 152 /* The strftime format to use for login times, and its expected
 153    output width.  */
 154 static char const *time_format;
 155 static int time_format_width;
 156
 157 /* for long options with no corresponding short option, use enum */
 158 enum
 159 {
 160   LOOKUP_OPTION = CHAR_MAX + 1
 161 };
 162
 163 static struct option const longopts[] = {
 164   {"all", no_argument, NULL, 'a'},
 165   {"boot", no_argument, NULL, 'b'},
 166   {"count", no_argument, NULL, 'q'},
 167   {"dead", no_argument, NULL, 'd'},
 168   {"heading", no_argument, NULL, 'H'},
 169   {"idle", no_argument, NULL, 'i'}, /* FIXME: deprecated: remove in late 2006 */
 170   {"login", no_argument, NULL, 'l'},
 171   {"lookup", no_argument, NULL, LOOKUP_OPTION},
 172   {"message", no_argument, NULL, 'T'},
 173   {"mesg", no_argument, NULL, 'T'},
 174   {"process", no_argument, NULL, 'p'},
 175   {"runlevel", no_argument, NULL, 'r'},
 176   {"short", no_argument, NULL, 's'},
 177   {"time", no_argument, NULL, 't'},
 178   {"users", no_argument, NULL, 'u'},
 179   {"writable", no_argument, NULL, 'T'},
 180   {GETOPT_HELP_OPTION_DECL},
 181   {GETOPT_VERSION_OPTION_DECL},
 182   {NULL, 0, NULL, 0}
 183 };
 184
 185 /* Return a string representing the time between WHEN and now.
 186    BOOTTIME is the time of last reboot.
 187    FIXME: locale? */
 188 static const char *
 189 idle_string (time_t when, time_t boottime)
 190 {
 191   static time_t now = TYPE_MINIMUM (time_t);
 192
 193   if (now == TYPE_MINIMUM (time_t))
 194     time (&now);
 195
 196   if (boottime < when && now - 24 * 60 * 60 < when && when <= now)
 197     {
 198       int seconds_idle = now - when;
 199       if (seconds_idle < 60)
 200         return "  .  ";
 201       else
 202         {
 203           static char idle_hhmm[IDLESTR_LEN];
 204           sprintf (idle_hhmm, "%02d:%02d",
 205                    seconds_idle / (60 * 60),
 206                    (seconds_idle % (60 * 60)) / 60);
 207           return idle_hhmm;
 208         }
 209     }
 210
 211   return _(" old ");
 212 }
 213
 214 /* Return a time string.  */
 215 static const char *
 216 time_string (const STRUCT_UTMP *utmp_ent)
 217 {
 218   static char buf[INT_STRLEN_BOUND (intmax_t) + sizeof "-%m-%d %H:%M"];
 219
 220   /* Don't take the address of UT_TIME_MEMBER directly.
 221      Ulrich Drepper wrote:
 222      ``... GNU libc (and perhaps other libcs as well) have extended
 223      utmp file formats which do not use a simple time_t ut_time field.
 224      In glibc, ut_time is a macro which selects for backward compatibility
 225      the tv_sec member of a struct timeval value.''  */
 226   time_t t = UT_TIME_MEMBER (utmp_ent);
 227   struct tm *tmp = localtime (&t);
 228
 229   if (tmp)
 230     {
 231       strftime (buf, sizeof buf, time_format, tmp);
 232       return buf;
 233     }
 234   else
 235     return TYPE_SIGNED (time_t) ? imaxtostr (t, buf) : umaxtostr (t, buf);
 236 }
 237
 238 /* Print formatted output line. Uses mostly arbitrary field sizes, probably
 239    will need tweaking if any of the localization stuff is done, or for 64 bit
 240    pids, etc. */
 241 static void
 242 print_line (int userlen, const char *user, const char state,
 243             int linelen, const char *line,
 244             const char *time_str, const char *idle, const char *pid,
 245             const char *comment, const char *exitstr)
 246 {
 247   static char mesg[3] = { ' ', 'x', '\0' };
 248   char *buf;
 249   char x_idle[1 + IDLESTR_LEN + 1];
 250   char x_pid[1 + INT_STRLEN_BOUND (pid_t) + 1];
 251   char *x_exitstr;
 252   int err;
 253
 254   mesg[1] = state;
 255
 256   if (include_idle && !short_output && strlen (idle) < sizeof x_idle - 1)
 257     sprintf (x_idle, " %-6s", idle);
 258   else
 259     *x_idle = '\0';
 260
 261   if (!short_output && strlen (pid) < sizeof x_pid - 1)
 262     sprintf (x_pid, " %10s", pid);
 263   else
 264     *x_pid = '\0';
 265
 266   x_exitstr = xmalloc (include_exit ? 1 + MAX (12, strlen (exitstr)) + 1 : 1);
 267   if (include_exit)
 268     sprintf (x_exitstr, " %-12s", exitstr);
 269   else
 270     *x_exitstr = '\0';
 271
 272   err = asprintf (&buf,
 273                   "%-8.*s"
 274                   "%s"
 275                   " %-12.*s"
 276                   " %-*s"
 277                   "%s"
 278                   "%s"
 279                   " %-8s"
 280                   "%s"
 281                   ,
 282                   userlen, user ? user : "   .",
 283                   include_mesg ? mesg : "",
 284                   linelen, line,
 285                   time_format_width,
 286                   time_str,
 287                   x_idle,
 288                   x_pid,
 289                   /* FIXME: it's not really clear whether the following
 290                      field should be in the short_output.  A strict reading
 291                      of SUSv2 would suggest not, but I haven't seen any
 292                      implementations that actually work that way... */
 293                   comment,
 294                   x_exitstr
 295                   );
 296   if (err == -1)
 297     xalloc_die ();
 298
 299   {
 300     /* Remove any trailing spaces.  */
 301     char *p = buf + strlen (buf);
 302     while (*--p == ' ')
 303       /* empty */;
 304     *(p + 1) = '\0';
 305   }
 306
 307   puts (buf);
 308   free (buf);
 309   free (x_exitstr);
 310 }
 311
 312 /* Send properly parsed USER_PROCESS info to print_line.  The most
 313    recent boot time is BOOTTIME. */
 314 static void
 315 print_user (const STRUCT_UTMP *utmp_ent, time_t boottime)
 316 {
 317   struct stat stats;
 318   time_t last_change;
 319   char mesg;
 320   char idlestr[IDLESTR_LEN + 1];
 321   static char *hoststr;
 322 #if HAVE_UT_HOST
 323   static size_t hostlen;
 324 #endif
 325
 326 #define DEV_DIR_WITH_TRAILING_SLASH "/dev/"
 327 #define DEV_DIR_LEN (sizeof (DEV_DIR_WITH_TRAILING_SLASH) - 1)
 328
 329   char line[sizeof (utmp_ent->ut_line) + DEV_DIR_LEN + 1];
 330   PIDSTR_DECL_AND_INIT (pidstr, utmp_ent);
 331
 332   /* Copy ut_line into LINE, prepending `/dev/' if ut_line is not
 333      already an absolute file name.  Some systems may put the full,
 334      absolute file name in ut_line.  */
 335   if (utmp_ent->ut_line[0] == '/')
 336     {
 337       strncpy (line, utmp_ent->ut_line, sizeof (utmp_ent->ut_line));
 338       line[sizeof (utmp_ent->ut_line)] = '\0';
 339     }
 340   else
 341     {
 342       strcpy (line, DEV_DIR_WITH_TRAILING_SLASH);
 343       strncpy (line + DEV_DIR_LEN, utmp_ent->ut_line,
 344                sizeof (utmp_ent->ut_line));
 345       line[DEV_DIR_LEN + sizeof (utmp_ent->ut_line)] = '\0';
 346     }
 347
 348   if (stat (line, &stats) == 0)
 349     {
 350       mesg = (stats.st_mode & S_IWGRP) ? '+' : '-';
 351       last_change = stats.st_atime;
 352     }
 353   else
 354     {
 355       mesg = '?';
 356       last_change = 0;
 357     }
 358
 359   if (last_change)
 360     sprintf (idlestr, "%.*s", IDLESTR_LEN, idle_string (last_change, boottime));
 361   else
 362     sprintf (idlestr, "  ?");
 363
 364 #if HAVE_UT_HOST
 365   if (utmp_ent->ut_host[0])
 366     {
 367       char ut_host[sizeof (utmp_ent->ut_host) + 1];
 368       char *host = NULL;
 369       char *display = NULL;
 370
 371       /* Copy the host name into UT_HOST, and ensure it's nul terminated. */
 372       strncpy (ut_host, utmp_ent->ut_host, sizeof (utmp_ent->ut_host));
 373       ut_host[sizeof (utmp_ent->ut_host)] = '\0';
 374
 375       /* Look for an X display.  */
 376       display = strchr (ut_host, ':');
 377       if (display)
 378         *display++ = '\0';
 379
 380       if (*ut_host && do_lookup)
 381         {
 382           /* See if we can canonicalize it.  */
 383           host = canon_host (ut_host);
 384         }
 385
 386       if (! host)
 387         host = ut_host;
 388
 389       if (display)
 390         {
 391           if (hostlen < strlen (host) + strlen (display) + 4)
 392             {
 393               hostlen = strlen (host) + strlen (display) + 4;
 394               hoststr = xrealloc (hoststr, hostlen);
 395             }
 396           sprintf (hoststr, "(%s:%s)", host, display);
 397         }
 398       else
 399         {
 400           if (hostlen < strlen (host) + 3)
 401             {
 402               hostlen = strlen (host) + 3;
 403               hoststr = xrealloc (hoststr, hostlen);
 404             }
 405           sprintf (hoststr, "(%s)", host);
 406         }
 407
 408       if (host != ut_host)
 409         free (host);
 410     }
 411   else
 412     {
 413       if (hostlen < 1)
 414         {
 415           hostlen = 1;
 416           hoststr = xrealloc (hoststr, hostlen);
 417         }
 418       *hoststr = '\0';
 419     }
 420 #endif
 421
 422   print_line (sizeof UT_USER (utmp_ent), UT_USER (utmp_ent), mesg,
 423               sizeof utmp_ent->ut_line, utmp_ent->ut_line,
 424               time_string (utmp_ent), idlestr, pidstr,
 425               hoststr ? hoststr : "", "");
 426 }
 427
 428 static void
 429 print_boottime (const STRUCT_UTMP *utmp_ent)
 430 {
 431   print_line (-1, "", ' ', -1, "system boot",
 432               time_string (utmp_ent), "", "", "", "");
 433 }
 434
 435 static char *
 436 make_id_equals_comment (STRUCT_UTMP const *utmp_ent)
 437 {
 438   char *comment = xmalloc (strlen (_("id=")) + sizeof UT_ID (utmp_ent) + 1);
 439
 440   strcpy (comment, _("id="));
 441   strncat (comment, UT_ID (utmp_ent), sizeof UT_ID (utmp_ent));
 442   return comment;
 443 }
 444
 445 static void
 446 print_deadprocs (const STRUCT_UTMP *utmp_ent)
 447 {
 448   static char *exitstr;
 449   char *comment = make_id_equals_comment (utmp_ent);
 450   PIDSTR_DECL_AND_INIT (pidstr, utmp_ent);
 451
 452   if (!exitstr)
 453     exitstr = xmalloc (strlen (_("term="))
 454                        + INT_STRLEN_BOUND (UT_EXIT_E_TERMINATION (utmp_ent)) + 1
 455                        + strlen (_("exit="))
 456                        + INT_STRLEN_BOUND (UT_EXIT_E_EXIT (utmp_ent))
 457                        + 1);
 458   sprintf (exitstr, "%s%d %s%d", _("term="), UT_EXIT_E_TERMINATION (utmp_ent),
 459            _("exit="), UT_EXIT_E_EXIT (utmp_ent));
 460
 461   /* FIXME: add idle time? */
 462
 463   print_line (-1, "", ' ', sizeof utmp_ent->ut_line, utmp_ent->ut_line,
 464               time_string (utmp_ent), "", pidstr, comment, exitstr);
 465   free (comment);
 466 }
 467
 468 static void
 469 print_login (const STRUCT_UTMP *utmp_ent)
 470 {
 471   char *comment = make_id_equals_comment (utmp_ent);
 472   PIDSTR_DECL_AND_INIT (pidstr, utmp_ent);
 473
 474   /* FIXME: add idle time? */
 475
 476   print_line (-1, "LOGIN", ' ', sizeof utmp_ent->ut_line, utmp_ent->ut_line,
 477               time_string (utmp_ent), "", pidstr, comment, "");
 478   free (comment);
 479 }
 480
 481 static void
 482 print_initspawn (const STRUCT_UTMP *utmp_ent)
 483 {
 484   char *comment = make_id_equals_comment (utmp_ent);
 485   PIDSTR_DECL_AND_INIT (pidstr, utmp_ent);
 486
 487   print_line (-1, "", ' ', sizeof utmp_ent->ut_line, utmp_ent->ut_line,
 488               time_string (utmp_ent), "", pidstr, comment, "");
 489   free (comment);
 490 }
 491
 492 static void
 493 print_clockchange (const STRUCT_UTMP *utmp_ent)
 494 {
 495   /* FIXME: handle NEW_TIME & OLD_TIME both */
 496   print_line (-1, "", ' ', -1, _("clock change"),
 497               time_string (utmp_ent), "", "", "", "");
 498 }
 499
 500 static void
 501 print_runlevel (const STRUCT_UTMP *utmp_ent)
 502 {
 503   static char *runlevline, *comment;
 504   unsigned char last = UT_PID (utmp_ent) / 256;
 505   unsigned char curr = UT_PID (utmp_ent) % 256;
 506
 507   if (!runlevline)
 508     runlevline = xmalloc (strlen (_("run-level")) + 3);
 509   sprintf (runlevline, "%s %c", _("run-level"), curr);
 510
 511   if (!comment)
 512     comment = xmalloc (strlen (_("last=")) + 2);
 513   sprintf (comment, "%s%c", _("last="), (last == 'N') ? 'S' : last);
 514
 515   print_line (-1, "", ' ', -1, runlevline, time_string (utmp_ent),
 516               "", "", comment, "");
 517
 518   return;
 519 }
 520
 521 /* Print the username of each valid entry and the number of valid entries
 522    in UTMP_BUF, which should have N elements. */
 523 static void
 524 list_entries_who (size_t n, const STRUCT_UTMP *utmp_buf)
 525 {
 526   unsigned long int entries = 0;
 527   char const *separator = "";
 528
 529   while (n--)
 530     {
 531       if (IS_USER_PROCESS (utmp_buf))
 532         {
 533           char *trimmed_name;
 534
 535           trimmed_name = extract_trimmed_name (utmp_buf);
 536
 537           printf ("%s%s", separator, trimmed_name);
 538           free (trimmed_name);
 539           separator = " ";
 540           entries++;
 541         }
 542       utmp_buf++;
 543     }
 544   printf (_("\n# users=%lu\n"), entries);
 545 }
 546
 547 static void
 548 print_heading (void)
 549 {
 550   print_line (-1, _("NAME"), ' ', -1, _("LINE"), _("TIME"), _("IDLE"),
 551               _("PID"), _("COMMENT"), _("EXIT"));
 552 }
 553
 554 /* Display UTMP_BUF, which should have N entries. */
 555 static void
 556 scan_entries (size_t n, const STRUCT_UTMP *utmp_buf)
 557 {
 558   char *ttyname_b IF_LINT ( = NULL);
 559   time_t boottime = TYPE_MINIMUM (time_t);
 560
 561   if (include_heading)
 562     print_heading ();
 563
 564   if (my_line_only)
 565     {
 566       ttyname_b = ttyname (STDIN_FILENO);
 567       if (!ttyname_b)
 568         return;
 569       if (strncmp (ttyname_b, DEV_DIR_WITH_TRAILING_SLASH, DEV_DIR_LEN) == 0)
 570         ttyname_b += DEV_DIR_LEN;       /* Discard /dev/ prefix.  */
 571     }
 572
 573   while (n--)
 574     {
 575       if (!my_line_only ||
 576           strncmp (ttyname_b, utmp_buf->ut_line,
 577                    sizeof (utmp_buf->ut_line)) == 0)
 578         {
 579           if (need_users && IS_USER_PROCESS (utmp_buf))
 580             print_user (utmp_buf, boottime);
 581           else if (need_runlevel && UT_TYPE_RUN_LVL (utmp_buf))
 582             print_runlevel (utmp_buf);
 583           else if (need_boottime && UT_TYPE_BOOT_TIME (utmp_buf))
 584             print_boottime (utmp_buf);
 585           /* I've never seen one of these, so I don't know what it should
 586              look like :^)
 587              FIXME: handle OLD_TIME also, perhaps show the delta? */
 588           else if (need_clockchange && UT_TYPE_NEW_TIME (utmp_buf))
 589             print_clockchange (utmp_buf);
 590           else if (need_initspawn && UT_TYPE_INIT_PROCESS (utmp_buf))
 591             print_initspawn (utmp_buf);
 592           else if (need_login && UT_TYPE_LOGIN_PROCESS (utmp_buf))
 593             print_login (utmp_buf);
 594           else if (need_deadprocs && UT_TYPE_DEAD_PROCESS (utmp_buf))
 595             print_deadprocs (utmp_buf);
 596         }
 597
 598       if (UT_TYPE_BOOT_TIME (utmp_buf))
 599         boottime = UT_TIME_MEMBER (utmp_buf);
 600
 601       utmp_buf++;
 602     }
 603 }
 604
 605 /* Display a list of who is on the system, according to utmp file FILENAME.
 606    Use read_utmp OPTIONS to read the file.  */
 607 static void
 608 who (const char *filename, int options)
 609 {
 610   size_t n_users;
 611   STRUCT_UTMP *utmp_buf;
 612
 613   if (read_utmp (filename, &n_users, &utmp_buf, options) != 0)
 614     error (EXIT_FAILURE, errno, "%s", filename);
 615
 616   if (short_list)
 617     list_entries_who (n_users, utmp_buf);
 618   else
 619     scan_entries (n_users, utmp_buf);
 620
 621   free (utmp_buf);
 622 }
 623
 624 void
 625 usage (int status)
 626 {
 627   if (status != EXIT_SUCCESS)
 628     fprintf (stderr, _("Try `%s --help' for more information.\n"),
 629              program_name);
 630   else
 631     {
 632       printf (_("Usage: %s [OPTION]... [ FILE | ARG1 ARG2 ]\n"), program_name);
 633       fputs (_("\
 634 \n\
 635   -a, --all         same as -b -d --login -p -r -t -T -u\n\
 636   -b, --boot        time of last system boot\n\
 637   -d, --dead        print dead processes\n\
 638   -H, --heading     print line of column headings\n\
 639 "), stdout);
 640       fputs (_("\
 641   -l, --login       print system login processes\n\
 642 "), stdout);
 643       fputs (_("\
 644       --lookup      attempt to canonicalize hostnames via DNS\n\
 645   -m                only hostname and user associated with stdin\n\
 646   -p, --process     print active processes spawned by init\n\
 647 "), stdout);
 648       fputs (_("\
 649   -q, --count       all login names and number of users logged on\n\
 650   -r, --runlevel    print current runlevel\n\
 651   -s, --short       print only name, line, and time (default)\n\
 652   -t, --time        print last system clock change\n\
 653 "), stdout);
 654       fputs (_("\
 655   -T, -w, --mesg    add user's message status as +, - or ?\n\
 656   -u, --users       list users logged in\n\
 657       --message     same as -T\n\
 658       --writable    same as -T\n\
 659 "), stdout);
 660       fputs (HELP_OPTION_DESCRIPTION, stdout);
 661       fputs (VERSION_OPTION_DESCRIPTION, stdout);
 662       printf (_("\
 663 \n\
 664 If FILE is not specified, use %s.  %s as FILE is common.\n\
 665 If ARG1 ARG2 given, -m presumed: `am i' or `mom likes' are usual.\n\
 666 "), UTMP_FILE, WTMP_FILE);
 667       emit_bug_reporting_address ();
 668     }
 669   exit (status);
 670 }
 671
 672 int
 673 main (int argc, char **argv)
 674 {
 675   int optc;
 676   bool assumptions = true;
 677
 678   initialize_main (&argc, &argv);
 679   program_name = argv[0];
 680   setlocale (LC_ALL, "");
 681   bindtextdomain (PACKAGE, LOCALEDIR);
 682   textdomain (PACKAGE);
 683
 684   atexit (close_stdout);
 685
 686   while ((optc = getopt_long (argc, argv, "abdilmpqrstuwHT", longopts, NULL))
 687          != -1)
 688     {
 689       switch (optc)
 690         {
 691         case 'a':
 692           need_boottime = true;
 693           need_deadprocs = true;
 694           need_login = true;
 695           need_initspawn = true;
 696           need_runlevel = true;
 697           need_clockchange = true;
 698           need_users = true;
 699           include_mesg = true;
 700           include_idle = true;
 701           include_exit = true;
 702           assumptions = false;
 703           break;
 704
 705         case 'b':
 706           need_boottime = true;
 707           assumptions = false;
 708           break;
 709
 710         case 'd':
 711           need_deadprocs = true;
 712           include_idle = true;
 713           include_exit = true;
 714           assumptions = false;
 715           break;
 716
 717         case 'H':
 718           include_heading = true;
 719           break;
 720
 721         case 'l':
 722           need_login = true;
 723           include_idle = true;
 724           assumptions = false;
 725           break;
 726
 727         case 'm':
 728           my_line_only = true;
 729           break;
 730
 731         case 'p':
 732           need_initspawn = true;
 733           assumptions = false;
 734           break;
 735
 736         case 'q':
 737           short_list = true;
 738           break;
 739
 740         case 'r':
 741           need_runlevel = true;
 742           include_idle = true;
 743           assumptions = false;
 744           break;
 745
 746         case 's':
 747           short_output = true;
 748           break;
 749
 750         case 't':
 751           need_clockchange = true;
 752           assumptions = false;
 753           break;
 754
 755         case 'T':
 756         case 'w':
 757           include_mesg = true;
 758           break;
 759
 760         case 'i':
 761           error (0, 0,
 762                  _("Warning: -i will be removed in a future release; \
 763   use -u instead"));
 764           /* Fall through.  */
 765         case 'u':
 766           need_users = true;
 767           include_idle = true;
 768           assumptions = false;
 769           break;
 770
 771         case LOOKUP_OPTION:
 772           do_lookup = true;
 773           break;
 774
 775           case_GETOPT_HELP_CHAR;
 776
 777           case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
 778
 779         default:
 780           usage (EXIT_FAILURE);
 781         }
 782     }
 783
 784   if (assumptions)
 785     {
 786       need_users = true;
 787       short_output = true;
 788     }
 789
 790   if (include_exit)
 791     {
 792       short_output = false;
 793     }
 794
 795   if (hard_locale (LC_TIME))
 796     {
 797       time_format = "%Y-%m-%d %H:%M";
 798       time_format_width = 4 + 1 + 2 + 1 + 2 + 1 + 2 + 1 + 2;
 799     }
 800   else
 801     {
 802       time_format = "%b %e %H:%M";
 803       time_format_width = 3 + 1 + 2 + 1 + 2 + 1 + 2;
 804     }
 805
 806   switch (argc - optind)
 807     {
 808     case 2:                     /* who <blurf> <glop> */
 809       my_line_only = true;
 810       /* Fall through.  */
 811     case -1:
 812     case 0:                     /* who */
 813       who (UTMP_FILE, READ_UTMP_CHECK_PIDS);
 814       break;
 815
 816     case 1:                     /* who <utmp file> */
 817       who (argv[optind], 0);
 818       break;
 819
 820     default:                    /* lose */
 821       error (0, 0, _("extra operand %s"), quote (argv[optind + 2]));
 822       usage (EXIT_FAILURE);
 823     }
 824
 825   exit (EXIT_SUCCESS);
 826 }