src/df.c

   1 /* df - summarize free disk space
   2    Copyright (C) 91, 1995-2006 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 David MacKenzie <djm@gnu.ai.mit.edu>.
  19    --human-readable and --megabyte options added by lm@sgi.com.
  20    --si and large file support added by eggert@twinsun.com.  */
  21
  22 #include <config.h>
  23 #include <stdio.h>
  24 #include <sys/types.h>
  25 #include <getopt.h>
  26
  27 #include "system.h"
  28 #include "canonicalize.h"
  29 #include "error.h"
  30 #include "fsusage.h"
  31 #include "human.h"
  32 #include "inttostr.h"
  33 #include "mountlist.h"
  34 #include "quote.h"
  35 #include "save-cwd.h"
  36 #include "xgetcwd.h"
  37
  38 /* The official name of this program (e.g., no `g' prefix).  */
  39 #define PROGRAM_NAME "df"
  40
  41 #define AUTHORS \
  42   "Torbjorn Granlund", "David MacKenzie", "Paul Eggert"
  43
  44 /* Name this program was run with. */
  45 char *program_name;
  46
  47 /* If true, show inode information. */
  48 static bool inode_format;
  49
  50 /* If true, show even file systems with zero size or
  51    uninteresting types. */
  52 static bool show_all_fs;
  53
  54 /* If true, show only local file systems.  */
  55 static bool show_local_fs;
  56
  57 /* If true, output data for each file system corresponding to a
  58    command line argument -- even if it's a dummy (automounter) entry.  */
  59 static bool show_listed_fs;
  60
  61 /* Human-readable options for output.  */
  62 static int human_output_opts;
  63
  64 /* The units to use when printing sizes.  */
  65 static uintmax_t output_block_size;
  66
  67 /* If true, use the POSIX output format.  */
  68 static bool posix_format;
  69
  70 /* True if a file system has been processed for output.  */
  71 static bool file_systems_processed;
  72
  73 /* If true, invoke the `sync' system call before getting any usage data.
  74    Using this option can make df very slow, especially with many or very
  75    busy disks.  Note that this may make a difference on some systems --
  76    SunOS 4.1.3, for one.  It is *not* necessary on Linux.  */
  77 static bool require_sync;
  78
  79 /* Desired exit status.  */
  80 static int exit_status;
  81
  82 /* A file system type to display. */
  83
  84 struct fs_type_list
  85 {
  86   char *fs_name;
  87   struct fs_type_list *fs_next;
  88 };
  89
  90 /* Linked list of file system types to display.
  91    If `fs_select_list' is NULL, list all types.
  92    This table is generated dynamically from command-line options,
  93    rather than hardcoding into the program what it thinks are the
  94    valid file system types; let the user specify any file system type
  95    they want to, and if there are any file systems of that type, they
  96    will be shown.
  97
  98    Some file system types:
  99    4.2 4.3 ufs nfs swap ignore io vm efs dbg */
 100
 101 static struct fs_type_list *fs_select_list;
 102
 103 /* Linked list of file system types to omit.
 104    If the list is empty, don't exclude any types.  */
 105
 106 static struct fs_type_list *fs_exclude_list;
 107
 108 /* Linked list of mounted file systems. */
 109 static struct mount_entry *mount_list;
 110
 111 /* If true, print file system type as well.  */
 112 static bool print_type;
 113
 114 /* For long options that have no equivalent short option, use a
 115    non-character as a pseudo short option, starting with CHAR_MAX + 1.  */
 116 enum
 117 {
 118   NO_SYNC_OPTION = CHAR_MAX + 1,
 119   /* FIXME: --kilobytes is deprecated (but not -k); remove in late 2006 */
 120   KILOBYTES_LONG_OPTION,
 121   SYNC_OPTION
 122 };
 123
 124 static struct option const long_options[] =
 125 {
 126   {"all", no_argument, NULL, 'a'},
 127   {"block-size", required_argument, NULL, 'B'},
 128   {"inodes", no_argument, NULL, 'i'},
 129   {"human-readable", no_argument, NULL, 'h'},
 130   {"si", no_argument, NULL, 'H'},
 131   {"kilobytes", no_argument, NULL, KILOBYTES_LONG_OPTION},
 132   {"local", no_argument, NULL, 'l'},
 133   {"megabytes", no_argument, NULL, 'm'}, /* obsolescent */
 134   {"portability", no_argument, NULL, 'P'},
 135   {"print-type", no_argument, NULL, 'T'},
 136   {"sync", no_argument, NULL, SYNC_OPTION},
 137   {"no-sync", no_argument, NULL, NO_SYNC_OPTION},
 138   {"type", required_argument, NULL, 't'},
 139   {"exclude-type", required_argument, NULL, 'x'},
 140   {GETOPT_HELP_OPTION_DECL},
 141   {GETOPT_VERSION_OPTION_DECL},
 142   {NULL, 0, NULL, 0}
 143 };
 144
 145 static void
 146 print_header (void)
 147 {
 148   char buf[MAX (LONGEST_HUMAN_READABLE + 1, INT_BUFSIZE_BOUND (uintmax_t))];
 149
 150   if (print_type)
 151     fputs (_("Filesystem    Type"), stdout);
 152   else
 153     fputs (_("Filesystem        "), stdout);
 154
 155   if (inode_format)
 156     printf (_("    Inodes   IUsed   IFree IUse%%"));
 157   else if (human_output_opts & human_autoscale)
 158     {
 159       if (human_output_opts & human_base_1024)
 160         printf (_("    Size  Used Avail Use%%"));
 161       else
 162         printf (_("     Size   Used  Avail Use%%"));
 163     }
 164   else if (posix_format)
 165     printf (_(" %s-blocks      Used Available Capacity"),
 166             umaxtostr (output_block_size, buf));
 167   else
 168     {
 169       int opts = (human_suppress_point_zero
 170                   | human_autoscale | human_SI
 171                   | (human_output_opts
 172                      & (human_group_digits | human_base_1024 | human_B)));
 173
 174       /* Prefer the base that makes the human-readable value more exact,
 175          if there is a difference.  */
 176
 177       uintmax_t q1000 = output_block_size;
 178       uintmax_t q1024 = output_block_size;
 179       bool divisible_by_1000;
 180       bool divisible_by_1024;
 181
 182       do
 183         {
 184           divisible_by_1000 = q1000 % 1000 == 0;  q1000 /= 1000;
 185           divisible_by_1024 = q1024 % 1024 == 0;  q1024 /= 1024;
 186         }
 187       while (divisible_by_1000 & divisible_by_1024);
 188
 189       if (divisible_by_1000 < divisible_by_1024)
 190         opts |= human_base_1024;
 191       if (divisible_by_1024 < divisible_by_1000)
 192         opts &= ~human_base_1024;
 193       if (! (opts & human_base_1024))
 194         opts |= human_B;
 195
 196       printf (_(" %4s-blocks      Used Available Use%%"),
 197               human_readable (output_block_size, buf, opts, 1, 1));
 198     }
 199
 200   printf (_(" Mounted on\n"));
 201 }
 202
 203 /* Is FSTYPE a type of file system that should be listed?  */
 204
 205 static bool
 206 selected_fstype (const char *fstype)
 207 {
 208   const struct fs_type_list *fsp;
 209
 210   if (fs_select_list == NULL || fstype == NULL)
 211     return true;
 212   for (fsp = fs_select_list; fsp; fsp = fsp->fs_next)
 213     if (STREQ (fstype, fsp->fs_name))
 214       return true;
 215   return false;
 216 }
 217
 218 /* Is FSTYPE a type of file system that should be omitted?  */
 219
 220 static bool
 221 excluded_fstype (const char *fstype)
 222 {
 223   const struct fs_type_list *fsp;
 224
 225   if (fs_exclude_list == NULL || fstype == NULL)
 226     return false;
 227   for (fsp = fs_exclude_list; fsp; fsp = fsp->fs_next)
 228     if (STREQ (fstype, fsp->fs_name))
 229       return true;
 230   return false;
 231 }
 232
 233 /* Like human_readable (N, BUF, human_output_opts, INPUT_UNITS, OUTPUT_UNITS),
 234    except:
 235
 236     - If NEGATIVE, then N represents a negative number,
 237       expressed in two's complement.
 238     - Otherwise, return "-" if N is UINTMAX_MAX.  */
 239
 240 static char const *
 241 df_readable (bool negative, uintmax_t n, char *buf,
 242              uintmax_t input_units, uintmax_t output_units)
 243 {
 244   if (n == UINTMAX_MAX && !negative)
 245     return "-";
 246   else
 247     {
 248       char *p = human_readable (negative ? -n : n, buf + negative,
 249                                 human_output_opts, input_units, output_units);
 250       if (negative)
 251         *--p = '-';
 252       return p;
 253     }
 254 }
 255
 256 /* Display a space listing for the disk device with absolute file name DISK.
 257    If MOUNT_POINT is non-NULL, it is the name of the root of the
 258    file system on DISK.
 259    If STAT_FILE is non-null, it is the name of a file within the file
 260    system that the user originally asked for; this provides better
 261    diagnostics, and sometimes it provides better results on networked
 262    file systems that give different free-space results depending on
 263    where in the file system you probe.
 264    If FSTYPE is non-NULL, it is the type of the file system on DISK.
 265    If MOUNT_POINT is non-NULL, then DISK may be NULL -- certain systems may
 266    not be able to produce statistics in this case.
 267    ME_DUMMY and ME_REMOTE are the mount entry flags.  */
 268
 269 static void
 270 show_dev (char const *disk, char const *mount_point,
 271           char const *stat_file, char const *fstype,
 272           bool me_dummy, bool me_remote)
 273 {
 274   struct fs_usage fsu;
 275   char buf[3][LONGEST_HUMAN_READABLE + 2];
 276   int width;
 277   int col1_adjustment = 0;
 278   int use_width;
 279   uintmax_t input_units;
 280   uintmax_t output_units;
 281   uintmax_t total;
 282   uintmax_t available;
 283   bool negate_available;
 284   uintmax_t available_to_root;
 285   uintmax_t used;
 286   bool negate_used;
 287   double pct = -1;
 288
 289   if (me_remote & show_local_fs)
 290     return;
 291
 292   if (me_dummy & !show_all_fs & !show_listed_fs)
 293     return;
 294
 295   if (!selected_fstype (fstype) || excluded_fstype (fstype))
 296     return;
 297
 298   /* If MOUNT_POINT is NULL, then the file system is not mounted, and this
 299      program reports on the file system that the special file is on.
 300      It would be better to report on the unmounted file system,
 301      but statfs doesn't do that on most systems.  */
 302   if (!stat_file)
 303     stat_file = mount_point ? mount_point : disk;
 304
 305   if (get_fs_usage (stat_file, disk, &fsu))
 306     {
 307       error (0, errno, "%s", quote (stat_file));
 308       exit_status = EXIT_FAILURE;
 309       return;
 310     }
 311
 312   if (fsu.fsu_blocks == 0 && !show_all_fs && !show_listed_fs)
 313     return;
 314
 315   if (! file_systems_processed)
 316     {
 317       file_systems_processed = true;
 318       print_header ();
 319     }
 320
 321   if (! disk)
 322     disk = "-";                 /* unknown */
 323   if (! fstype)
 324     fstype = "-";               /* unknown */
 325
 326   /* df.c reserved 5 positions for fstype,
 327      but that does not suffice for type iso9660 */
 328   if (print_type)
 329     {
 330       size_t disk_name_len = strlen (disk);
 331       size_t fstype_len = strlen (fstype);
 332       if (disk_name_len + fstype_len < 18)
 333         printf ("%s%*s  ", disk, 18 - (int) disk_name_len, fstype);
 334       else if (!posix_format)
 335         printf ("%s\n%18s  ", disk, fstype);
 336       else
 337         printf ("%s %s", disk, fstype);
 338     }
 339   else
 340     {
 341       if (strlen (disk) > 20 && !posix_format)
 342         printf ("%s\n%20s", disk, "");
 343       else
 344         printf ("%-20s", disk);
 345     }
 346
 347   if (inode_format)
 348     {
 349       width = 7;
 350       use_width = 5;
 351       input_units = output_units = 1;
 352       total = fsu.fsu_files;
 353       available = fsu.fsu_ffree;
 354       negate_available = false;
 355       available_to_root = available;
 356     }
 357   else
 358     {
 359       if (human_output_opts & human_autoscale)
 360         width = 5 + ! (human_output_opts & human_base_1024);
 361       else
 362         {
 363           width = 9;
 364           if (posix_format)
 365             {
 366               uintmax_t b;
 367               col1_adjustment = -3;
 368               for (b = output_block_size; 9 < b; b /= 10)
 369                 col1_adjustment++;
 370             }
 371         }
 372       use_width = ((posix_format
 373                     && ! (human_output_opts & human_autoscale))
 374                    ? 8 : 4);
 375       input_units = fsu.fsu_blocksize;
 376       output_units = output_block_size;
 377       total = fsu.fsu_blocks;
 378       available = fsu.fsu_bavail;
 379       negate_available = (fsu.fsu_bavail_top_bit_set
 380                           & (available != UINTMAX_MAX));
 381       available_to_root = fsu.fsu_bfree;
 382     }
 383
 384   used = UINTMAX_MAX;
 385   negate_used = false;
 386   if (total != UINTMAX_MAX && available_to_root != UINTMAX_MAX)
 387     {
 388       used = total - available_to_root;
 389       negate_used = (total < available_to_root);
 390     }
 391
 392   printf (" %*s %*s %*s ",
 393           width + col1_adjustment,
 394           df_readable (false, total,
 395                        buf[0], input_units, output_units),
 396           width, df_readable (negate_used, used,
 397                               buf[1], input_units, output_units),
 398           width, df_readable (negate_available, available,
 399                               buf[2], input_units, output_units));
 400
 401   if (used == UINTMAX_MAX || available == UINTMAX_MAX)
 402     ;
 403   else if (!negate_used
 404            && used <= TYPE_MAXIMUM (uintmax_t) / 100
 405            && used + available != 0
 406            && (used + available < used) == negate_available)
 407     {
 408       uintmax_t u100 = used * 100;
 409       uintmax_t nonroot_total = used + available;
 410       pct = u100 / nonroot_total + (u100 % nonroot_total != 0);
 411     }
 412   else
 413     {
 414       /* The calculation cannot be done easily with integer
 415          arithmetic.  Fall back on floating point.  This can suffer
 416          from minor rounding errors, but doing it exactly requires
 417          multiple precision arithmetic, and it's not worth the
 418          aggravation.  */
 419       double u = negate_used ? - (double) - used : used;
 420       double a = negate_available ? - (double) - available : available;
 421       double nonroot_total = u + a;
 422       if (nonroot_total)
 423         {
 424           long int lipct = pct = u * 100 / nonroot_total;
 425           double ipct = lipct;
 426
 427           /* Like `pct = ceil (dpct);', but avoid ceil so that
 428              the math library needn't be linked.  */
 429           if (ipct - 1 < pct && pct <= ipct + 1)
 430             pct = ipct + (ipct < pct);
 431         }
 432     }
 433
 434   if (0 <= pct)
 435     printf ("%*.0f%%", use_width - 1, pct);
 436   else
 437     printf ("%*s", use_width, "- ");
 438
 439   if (mount_point)
 440     {
 441 #ifdef HIDE_AUTOMOUNT_PREFIX
 442       /* Don't print the first directory name in MOUNT_POINT if it's an
 443          artifact of an automounter.  This is a bit too aggressive to be
 444          the default.  */
 445       if (strncmp ("/auto/", mount_point, 6) == 0)
 446         mount_point += 5;
 447       else if (strncmp ("/tmp_mnt/", mount_point, 9) == 0)
 448         mount_point += 8;
 449 #endif
 450       printf (" %s", mount_point);
 451     }
 452   putchar ('\n');
 453 }
 454
 455 /* Return the root mountpoint of the file system on which FILE exists, in
 456    malloced storage.  FILE_STAT should be the result of stating FILE.
 457    Give a diagnostic and return NULL if unable to determine the mount point.
 458    Exit if unable to restore current working directory.  */
 459 static char *
 460 find_mount_point (const char *file, const struct stat *file_stat)
 461 {
 462   struct saved_cwd cwd;
 463   struct stat last_stat;
 464   char *mp = NULL;              /* The malloced mount point.  */
 465
 466   if (save_cwd (&cwd) != 0)
 467     {
 468       error (0, errno, _("cannot get current directory"));
 469       return NULL;
 470     }
 471
 472   if (S_ISDIR (file_stat->st_mode))
 473     /* FILE is a directory, so just chdir there directly.  */
 474     {
 475       last_stat = *file_stat;
 476       if (chdir (file) < 0)
 477         {
 478           error (0, errno, _("cannot change to directory %s"), quote (file));
 479           return NULL;
 480         }
 481     }
 482   else
 483     /* FILE is some other kind of file; use its directory.  */
 484     {
 485       char *xdir = dir_name (file);
 486       char *dir;
 487       ASSIGN_STRDUPA (dir, xdir);
 488       free (xdir);
 489
 490       if (chdir (dir) < 0)
 491         {
 492           error (0, errno, _("cannot change to directory %s"), quote (dir));
 493           return NULL;
 494         }
 495
 496       if (stat (".", &last_stat) < 0)
 497         {
 498           error (0, errno, _("cannot stat current directory (now %s)"),
 499                  quote (dir));
 500           goto done;
 501         }
 502     }
 503
 504   /* Now walk up FILE's parents until we find another file system or /,
 505      chdiring as we go.  LAST_STAT holds stat information for the last place
 506      we visited.  */
 507   for (;;)
 508     {
 509       struct stat st;
 510       if (stat ("..", &st) < 0)
 511         {
 512           error (0, errno, _("cannot stat %s"), quote (".."));
 513           goto done;
 514         }
 515       if (st.st_dev != last_stat.st_dev || st.st_ino == last_stat.st_ino)
 516         /* cwd is the mount point.  */
 517         break;
 518       if (chdir ("..") < 0)
 519         {
 520           error (0, errno, _("cannot change to directory %s"), quote (".."));
 521           goto done;
 522         }
 523       last_stat = st;
 524     }
 525
 526   /* Finally reached a mount point, see what it's called.  */
 527   mp = xgetcwd ();
 528
 529 done:
 530   /* Restore the original cwd.  */
 531   {
 532     int save_errno = errno;
 533     if (restore_cwd (&cwd) != 0)
 534       error (EXIT_FAILURE, errno,
 535              _("failed to return to initial working directory"));
 536     free_cwd (&cwd);
 537     errno = save_errno;
 538   }
 539
 540   return mp;
 541 }
 542
 543 /* If DISK corresponds to a mount point, show its usage
 544    and return true.  Otherwise, return false.  */
 545 static bool
 546 show_disk (char const *disk)
 547 {
 548   struct mount_entry const *me;
 549   struct mount_entry const *best_match = NULL;
 550
 551   for (me = mount_list; me; me = me->me_next)
 552     if (STREQ (disk, me->me_devname))
 553       best_match = me;
 554
 555   if (best_match)
 556     {
 557       show_dev (best_match->me_devname, best_match->me_mountdir, NULL,
 558                 best_match->me_type, best_match->me_dummy,
 559                 best_match->me_remote);
 560       return true;
 561     }
 562
 563   return false;
 564 }
 565
 566 /* Figure out which device file or directory POINT is mounted on
 567    and show its disk usage.
 568    STATP must be the result of `stat (POINT, STATP)'.  */
 569 static void
 570 show_point (const char *point, const struct stat *statp)
 571 {
 572   struct stat disk_stats;
 573   struct mount_entry *me;
 574   struct mount_entry const *best_match = NULL;
 575
 576   /* If POINT is an absolute file name, see if we can find the
 577      mount point without performing any extra stat calls at all.  */
 578   if (*point == '/')
 579     {
 580       /* Find the best match: prefer non-dummies, and then prefer the
 581          last match if there are ties.  */
 582
 583       for (me = mount_list; me; me = me->me_next)
 584         if (STREQ (me->me_mountdir, point) && !STREQ (me->me_type, "lofs")
 585             && (!best_match || best_match->me_dummy || !me->me_dummy))
 586           best_match = me;
 587     }
 588
 589   /* Calculate the real absolute file name for POINT, and use that to find
 590      the mount point.  This avoids statting unavailable mount points,
 591      which can hang df.  */
 592   if (! best_match)
 593     {
 594       char *resolved = canonicalize_file_name (point);
 595
 596       if (resolved && resolved[0] == '/')
 597         {
 598           size_t resolved_len = strlen (resolved);
 599           size_t best_match_len = 0;
 600
 601           for (me = mount_list; me; me = me->me_next)
 602             if (!STREQ (me->me_type, "lofs")
 603                 && (!best_match || best_match->me_dummy || !me->me_dummy))
 604               {
 605                 size_t len = strlen (me->me_mountdir);
 606                 if (best_match_len <= len && len <= resolved_len
 607                     && (len == 1 /* root file system */
 608                         || ((len == resolved_len || resolved[len] == '/')
 609                             && strncmp (me->me_mountdir, resolved, len) == 0)))
 610                   {
 611                     best_match = me;
 612                     best_match_len = len;
 613                   }
 614               }
 615         }
 616
 617       free (resolved);
 618
 619       if (best_match
 620           && (stat (best_match->me_mountdir, &disk_stats) != 0
 621               || disk_stats.st_dev != statp->st_dev))
 622         best_match = NULL;
 623     }
 624
 625   if (! best_match)
 626     for (me = mount_list; me; me = me->me_next)
 627       {
 628         if (me->me_dev == (dev_t) -1)
 629           {
 630             if (stat (me->me_mountdir, &disk_stats) == 0)
 631               me->me_dev = disk_stats.st_dev;
 632             else
 633               {
 634                 /* Report only I/O errors.  Other errors might be
 635                    caused by shadowed mount points, which means POINT
 636                    can't possibly be on this file system.  */
 637                 if (errno == EIO)
 638                   {
 639                     error (0, errno, "%s", quote (me->me_mountdir));
 640                     exit_status = EXIT_FAILURE;
 641                   }
 642
 643                 /* So we won't try and fail repeatedly. */
 644                 me->me_dev = (dev_t) -2;
 645               }
 646           }
 647
 648         if (statp->st_dev == me->me_dev
 649             && !STREQ (me->me_type, "lofs")
 650             && (!best_match || best_match->me_dummy || !me->me_dummy))
 651           {
 652             /* Skip bogus mtab entries.  */
 653             if (stat (me->me_mountdir, &disk_stats) != 0
 654                 || disk_stats.st_dev != me->me_dev)
 655               me->me_dev = (dev_t) -2;
 656             else
 657               best_match = me;
 658           }
 659       }
 660
 661   if (best_match)
 662     show_dev (best_match->me_devname, best_match->me_mountdir, point,
 663               best_match->me_type, best_match->me_dummy, best_match->me_remote);
 664   else
 665     {
 666       /* We couldn't find the mount entry corresponding to POINT.  Go ahead and
 667          print as much info as we can; methods that require the device to be
 668          present will fail at a later point.  */
 669
 670       /* Find the actual mount point.  */
 671       char *mp = find_mount_point (point, statp);
 672       if (mp)
 673         {
 674           show_dev (NULL, mp, NULL, NULL, false, false);
 675           free (mp);
 676         }
 677     }
 678 }
 679
 680 /* Determine what kind of node NAME is and show the disk usage
 681    for it.  STATP is the results of `stat' on NAME.  */
 682
 683 static void
 684 show_entry (char const *name, struct stat const *statp)
 685 {
 686   if ((S_ISBLK (statp->st_mode) || S_ISCHR (statp->st_mode))
 687       && show_disk (name))
 688     return;
 689
 690   show_point (name, statp);
 691 }
 692
 693 /* Show all mounted file systems, except perhaps those that are of
 694    an unselected type or are empty. */
 695
 696 static void
 697 show_all_entries (void)
 698 {
 699   struct mount_entry *me;
 700
 701   for (me = mount_list; me; me = me->me_next)
 702     show_dev (me->me_devname, me->me_mountdir, NULL, me->me_type,
 703               me->me_dummy, me->me_remote);
 704 }
 705
 706 /* Add FSTYPE to the list of file system types to display. */
 707
 708 static void
 709 add_fs_type (const char *fstype)
 710 {
 711   struct fs_type_list *fsp;
 712
 713   fsp = xmalloc (sizeof *fsp);
 714   fsp->fs_name = (char *) fstype;
 715   fsp->fs_next = fs_select_list;
 716   fs_select_list = fsp;
 717 }
 718
 719 /* Add FSTYPE to the list of file system types to be omitted. */
 720
 721 static void
 722 add_excluded_fs_type (const char *fstype)
 723 {
 724   struct fs_type_list *fsp;
 725
 726   fsp = xmalloc (sizeof *fsp);
 727   fsp->fs_name = (char *) fstype;
 728   fsp->fs_next = fs_exclude_list;
 729   fs_exclude_list = fsp;
 730 }
 731
 732 void
 733 usage (int status)
 734 {
 735   if (status != EXIT_SUCCESS)
 736     fprintf (stderr, _("Try `%s --help' for more information.\n"),
 737              program_name);
 738   else
 739     {
 740       printf (_("Usage: %s [OPTION]... [FILE]...\n"), program_name);
 741       fputs (_("\
 742 Show information about the file system on which each FILE resides,\n\
 743 or all file systems by default.\n\
 744 \n\
 745 "), stdout);
 746       fputs (_("\
 747 Mandatory arguments to long options are mandatory for short options too.\n\
 748 "), stdout);
 749       fputs (_("\
 750   -a, --all             include dummy file systems\n\
 751   -B, --block-size=SIZE use SIZE-byte blocks\n\
 752   -h, --human-readable  print sizes in human readable format (e.g., 1K 234M 2G)\n\
 753   -H, --si              likewise, but use powers of 1000 not 1024\n\
 754 "), stdout);
 755       fputs (_("\
 756   -i, --inodes          list inode information instead of block usage\n\
 757   -k                    like --block-size=1K\n\
 758   -l, --local           limit listing to local file systems\n\
 759       --no-sync         do not invoke sync before getting usage info (default)\n\
 760 "), stdout);
 761       fputs (_("\
 762   -P, --portability     use the POSIX output format\n\
 763       --sync            invoke sync before getting usage info\n\
 764   -t, --type=TYPE       limit listing to file systems of type TYPE\n\
 765   -T, --print-type      print file system type\n\
 766   -x, --exclude-type=TYPE   limit listing to file systems not of type TYPE\n\
 767   -v                    (ignored)\n\
 768 "), stdout);
 769       fputs (HELP_OPTION_DESCRIPTION, stdout);
 770       fputs (VERSION_OPTION_DESCRIPTION, stdout);
 771       fputs (_("\n\
 772 SIZE may be (or may be an integer optionally followed by) one of following:\n\
 773 kB 1000, K 1024, MB 1000*1000, M 1024*1024, and so on for G, T, P, E, Z, Y.\n\
 774 "), stdout);
 775       printf (_("\nReport bugs to <%s>.\n"), PACKAGE_BUGREPORT);
 776     }
 777   exit (status);
 778 }
 779
 780 int
 781 main (int argc, char **argv)
 782 {
 783   int c;
 784   struct stat *stats IF_LINT (= 0);
 785
 786   initialize_main (&argc, &argv);
 787   program_name = argv[0];
 788   setlocale (LC_ALL, "");
 789   bindtextdomain (PACKAGE, LOCALEDIR);
 790   textdomain (PACKAGE);
 791
 792   atexit (close_stdout);
 793
 794   fs_select_list = NULL;
 795   fs_exclude_list = NULL;
 796   inode_format = false;
 797   show_all_fs = false;
 798   show_listed_fs = false;
 799
 800   human_output_opts = human_options (getenv ("DF_BLOCK_SIZE"), false,
 801                                      &output_block_size);
 802
 803   print_type = false;
 804   file_systems_processed = false;
 805   posix_format = false;
 806   exit_status = EXIT_SUCCESS;
 807
 808   while ((c = getopt_long (argc, argv, "aB:iF:hHklmPTt:vx:", long_options, NULL))
 809          != -1)
 810     {
 811       switch (c)
 812         {
 813         case 'a':
 814           show_all_fs = true;
 815           break;
 816         case 'B':
 817           human_output_opts = human_options (optarg, true, &output_block_size);
 818           break;
 819         case 'i':
 820           inode_format = true;
 821           break;
 822         case 'h':
 823           human_output_opts = human_autoscale | human_SI | human_base_1024;
 824           output_block_size = 1;
 825           break;
 826         case 'H':
 827           human_output_opts = human_autoscale | human_SI;
 828           output_block_size = 1;
 829           break;
 830         case KILOBYTES_LONG_OPTION:
 831           error (0, 0,
 832                  _("the --kilobytes option is deprecated; use -k instead"));
 833           /* fall through */
 834         case 'k':
 835           human_output_opts = 0;
 836           output_block_size = 1024;
 837           break;
 838         case 'l':
 839           show_local_fs = true;
 840           break;
 841         case 'm': /* obsolescent */
 842           human_output_opts = 0;
 843           output_block_size = 1024 * 1024;
 844           break;
 845         case 'T':
 846           print_type = true;
 847           break;
 848         case 'P':
 849           posix_format = true;
 850           break;
 851         case SYNC_OPTION:
 852           require_sync = true;
 853           break;
 854         case NO_SYNC_OPTION:
 855           require_sync = false;
 856           break;
 857
 858         case 'F':
 859           /* Accept -F as a synonym for -t for compatibility with Solaris.  */
 860         case 't':
 861           add_fs_type (optarg);
 862           break;
 863
 864         case 'v':               /* For SysV compatibility. */
 865           /* ignore */
 866           break;
 867         case 'x':
 868           add_excluded_fs_type (optarg);
 869           break;
 870
 871         case_GETOPT_HELP_CHAR;
 872         case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
 873
 874         default:
 875           usage (EXIT_FAILURE);
 876         }
 877     }
 878
 879   /* Fail if the same file system type was both selected and excluded.  */
 880   {
 881     bool match = false;
 882     struct fs_type_list *fs_incl;
 883     for (fs_incl = fs_select_list; fs_incl; fs_incl = fs_incl->fs_next)
 884       {
 885         struct fs_type_list *fs_excl;
 886         for (fs_excl = fs_exclude_list; fs_excl; fs_excl = fs_excl->fs_next)
 887           {
 888             if (STREQ (fs_incl->fs_name, fs_excl->fs_name))
 889               {
 890                 error (0, 0,
 891                        _("file system type %s both selected and excluded"),
 892                        quote (fs_incl->fs_name));
 893                 match = true;
 894                 break;
 895               }
 896           }
 897       }
 898     if (match)
 899       exit (EXIT_FAILURE);
 900   }
 901
 902   if (optind < argc)
 903     {
 904       int i;
 905
 906       /* stat all the given entries to make sure they get automounted,
 907          if necessary, before reading the file system table.  */
 908       stats = xnmalloc (argc - optind, sizeof *stats);
 909       for (i = optind; i < argc; ++i)
 910         {
 911           if (stat (argv[i], &stats[i - optind]))
 912             {
 913               error (0, errno, "%s", quote (argv[i]));
 914               exit_status = EXIT_FAILURE;
 915               argv[i] = NULL;
 916             }
 917         }
 918     }
 919
 920   mount_list =
 921     read_file_system_list ((fs_select_list != NULL
 922                             || fs_exclude_list != NULL
 923                             || print_type
 924                             || show_local_fs));
 925
 926   if (mount_list == NULL)
 927     {
 928       /* Couldn't read the table of mounted file systems.
 929          Fail if df was invoked with no file name arguments;
 930          Otherwise, merely give a warning and proceed.  */
 931       const char *warning = (optind < argc ? _("Warning: ") : "");
 932       int status = (optind < argc ? 0 : EXIT_FAILURE);
 933       error (status, errno,
 934              _("%scannot read table of mounted file systems"), warning);
 935     }
 936
 937   if (require_sync)
 938     sync ();
 939
 940   if (optind < argc)
 941     {
 942       int i;
 943
 944       /* Display explicitly requested empty file systems. */
 945       show_listed_fs = true;
 946
 947       for (i = optind; i < argc; ++i)
 948         if (argv[i])
 949           show_entry (argv[i], &stats[i - optind]);
 950     }
 951   else
 952     show_all_entries ();
 953
 954   if (! file_systems_processed)
 955     error (EXIT_FAILURE, 0, _("no file systems processed"));
 956
 957   exit (exit_status);
 958 }