coreutils/df.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * Mini df implementation for busybox
   4  *
   5  * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
   6  * based on original code by (I think) Bruce Perens <bruce@pixar.com>.
   7  *
   8  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
   9  */
  10
  11 /* BB_AUDIT SUSv3 _NOT_ compliant -- option -t missing. */
  12 /* http://www.opengroup.org/onlinepubs/007904975/utilities/df.html */
  13
  14 /* Mar 16, 2003      Manuel Novoa III   (mjn3@codepoet.org)
  15  *
  16  * Size reduction.  Removed floating point dependency.  Added error checking
  17  * on output.  Output stats on 0-sized filesystems if specifically listed on
  18  * the command line.  Properly round *-blocks, Used, and Available quantities.
  19  *
  20  * Aug 28, 2008      Bernhard Reutner-Fischer
  21  *
  22  * Implement -P and -B; better coreutils compat; cleanup
  23  */
  24
  25 //usage:#define df_trivial_usage
  26 //usage:        "[-Pk"
  27 //usage:        IF_FEATURE_HUMAN_READABLE("mh")
  28 //usage:        IF_FEATURE_DF_FANCY("ai] [-B SIZE")
  29 //usage:        "] [FILESYSTEM]..."
  30 //usage:#define df_full_usage "\n\n"
  31 //usage:       "Print filesystem usage statistics\n"
  32 //usage:     "\nOptions:"
  33 //usage:     "\n        -P      POSIX output format"
  34 //usage:     "\n        -k      1024-byte blocks (default)"
  35 //usage:        IF_FEATURE_HUMAN_READABLE(
  36 //usage:     "\n        -m      1M-byte blocks"
  37 //usage:     "\n        -h      Human readable (e.g. 1K 243M 2G)"
  38 //usage:        )
  39 //usage:        IF_FEATURE_DF_FANCY(
  40 //usage:     "\n        -a      Show all filesystems"
  41 //usage:     "\n        -i      Inodes"
  42 //usage:     "\n        -B SIZE Blocksize"
  43 //usage:        )
  44 //usage:
  45 //usage:#define df_example_usage
  46 //usage:       "$ df\n"
  47 //usage:       "Filesystem           1K-blocks      Used Available Use% Mounted on\n"
  48 //usage:       "/dev/sda3              8690864   8553540    137324  98% /\n"
  49 //usage:       "/dev/sda1                64216     36364     27852  57% /boot\n"
  50 //usage:       "$ df /dev/sda3\n"
  51 //usage:       "Filesystem           1K-blocks      Used Available Use% Mounted on\n"
  52 //usage:       "/dev/sda3              8690864   8553540    137324  98% /\n"
  53 //usage:       "$ POSIXLY_CORRECT=sure df /dev/sda3\n"
  54 //usage:       "Filesystem         512B-blocks      Used Available Use% Mounted on\n"
  55 //usage:       "/dev/sda3             17381728  17107080    274648  98% /\n"
  56 //usage:       "$ POSIXLY_CORRECT=yep df -P /dev/sda3\n"
  57 //usage:       "Filesystem          512-blocks      Used Available Capacity Mounted on\n"
  58 //usage:       "/dev/sda3             17381728  17107080    274648      98% /\n"
  59
  60 #include <mntent.h>
  61 #include <sys/vfs.h>
  62 #include "libbb.h"
  63 #include "unicode.h"
  64
  65 #if !ENABLE_FEATURE_HUMAN_READABLE
  66 static unsigned long kscale(unsigned long b, unsigned long bs)
  67 {
  68         return (b * (unsigned long long) bs + 1024/2) / 1024;
  69 }
  70 #endif
  71
  72 int df_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  73 int df_main(int argc UNUSED_PARAM, char **argv)
  74 {
  75         unsigned long blocks_used;
  76         unsigned blocks_percent_used;
  77         unsigned long df_disp_hr = 1024;
  78         int status = EXIT_SUCCESS;
  79         unsigned opt;
  80         FILE *mount_table;
  81         struct mntent *mount_entry;
  82         struct statfs s;
  83
  84         enum {
  85                 OPT_KILO  = (1 << 0),
  86                 OPT_POSIX = (1 << 1),
  87                 OPT_ALL   = (1 << 2) * ENABLE_FEATURE_DF_FANCY,
  88                 OPT_INODE = (1 << 3) * ENABLE_FEATURE_DF_FANCY,
  89                 OPT_BSIZE = (1 << 4) * ENABLE_FEATURE_DF_FANCY,
  90                 OPT_HUMAN = (1 << (2 + 3*ENABLE_FEATURE_DF_FANCY)) * ENABLE_FEATURE_HUMAN_READABLE,
  91                 OPT_MEGA  = (1 << (3 + 3*ENABLE_FEATURE_DF_FANCY)) * ENABLE_FEATURE_HUMAN_READABLE,
  92         };
  93         const char *disp_units_hdr = NULL;
  94         char *chp;
  95
  96         init_unicode();
  97
  98 #if ENABLE_FEATURE_HUMAN_READABLE && ENABLE_FEATURE_DF_FANCY
  99         opt_complementary = "k-mB:m-Bk:B-km";
 100 #elif ENABLE_FEATURE_HUMAN_READABLE
 101         opt_complementary = "k-m:m-k";
 102 #endif
 103         opt = getopt32(argv, "kP"
 104                         IF_FEATURE_DF_FANCY("aiB:")
 105                         IF_FEATURE_HUMAN_READABLE("hm")
 106                         IF_FEATURE_DF_FANCY(, &chp));
 107         if (opt & OPT_MEGA)
 108                 df_disp_hr = 1024*1024;
 109
 110         if (opt & OPT_BSIZE)
 111                 df_disp_hr = xatoul_range(chp, 1, ULONG_MAX); /* disallow 0 */
 112
 113         /* From the manpage of df from coreutils-6.10:
 114            Disk space is shown in 1K blocks by default, unless the environment
 115            variable POSIXLY_CORRECT is set, in which case 512-byte blocks are used.
 116         */
 117         if (getenv("POSIXLY_CORRECT")) /* TODO - a new libbb function? */
 118                 df_disp_hr = 512;
 119
 120         if (opt & OPT_HUMAN) {
 121                 df_disp_hr = 0;
 122                 disp_units_hdr = "     Size";
 123         }
 124         if (opt & OPT_INODE)
 125                 disp_units_hdr = "   Inodes";
 126
 127         if (disp_units_hdr == NULL) {
 128 #if ENABLE_FEATURE_HUMAN_READABLE
 129                 disp_units_hdr = xasprintf("%s-blocks",
 130                         /* print df_disp_hr, show no fractionals,
 131                          * use suffixes if OPT_POSIX is set in opt */
 132                         make_human_readable_str(df_disp_hr, 0, !!(opt & OPT_POSIX))
 133                 );
 134 #else
 135                 disp_units_hdr = xasprintf("%lu-blocks", df_disp_hr);
 136 #endif
 137         }
 138         printf("Filesystem           %-15sUsed Available %s Mounted on\n",
 139                         disp_units_hdr, (opt & OPT_POSIX) ? "Capacity" : "Use%");
 140
 141         mount_table = NULL;
 142         argv += optind;
 143         if (!argv[0]) {
 144                 mount_table = setmntent(bb_path_mtab_file, "r");
 145                 if (!mount_table)
 146                         bb_perror_msg_and_die(bb_path_mtab_file);
 147         }
 148
 149         while (1) {
 150                 const char *device;
 151                 const char *mount_point;
 152
 153                 if (mount_table) {
 154                         mount_entry = getmntent(mount_table);
 155                         if (!mount_entry) {
 156                                 endmntent(mount_table);
 157                                 break;
 158                         }
 159                 } else {
 160                         mount_point = *argv++;
 161                         if (!mount_point)
 162                                 break;
 163                         mount_entry = find_mount_point(mount_point, 1);
 164                         if (!mount_entry) {
 165                                 bb_error_msg("%s: can't find mount point", mount_point);
 166  set_error:
 167                                 status = EXIT_FAILURE;
 168                                 continue;
 169                         }
 170                 }
 171
 172                 device = mount_entry->mnt_fsname;
 173                 mount_point = mount_entry->mnt_dir;
 174
 175                 if (statfs(mount_point, &s) != 0) {
 176                         bb_simple_perror_msg(mount_point);
 177                         goto set_error;
 178                 }
 179
 180                 if ((s.f_blocks > 0) || !mount_table || (opt & OPT_ALL)) {
 181                         if (opt & OPT_INODE) {
 182                                 s.f_blocks = s.f_files;
 183                                 s.f_bavail = s.f_bfree = s.f_ffree;
 184                                 s.f_bsize = 1;
 185
 186                                 if (df_disp_hr)
 187                                         df_disp_hr = 1;
 188                         }
 189                         blocks_used = s.f_blocks - s.f_bfree;
 190                         blocks_percent_used = 0;
 191                         if (blocks_used + s.f_bavail) {
 192                                 blocks_percent_used = (blocks_used * 100ULL
 193                                                 + (blocks_used + s.f_bavail)/2
 194                                                 ) / (blocks_used + s.f_bavail);
 195                         }
 196
 197                         /* GNU coreutils 6.10 skips certain mounts, try to be compatible.  */
 198                         if (ENABLE_FEATURE_SKIP_ROOTFS && strcmp(device, "rootfs") == 0)
 199                                 continue;
 200
 201 #ifdef WHY_WE_DO_IT_FOR_DEV_ROOT_ONLY
 202                         if (strcmp(device, "/dev/root") == 0) {
 203                                 /* Adjusts device to be the real root device,
 204                                  * or leaves device alone if it can't find it */
 205                                 device = find_block_device("/");
 206                                 if (!device) {
 207                                         goto set_error;
 208                                 }
 209                         }
 210 #endif
 211
 212 #if ENABLE_UNICODE_SUPPORT
 213                         {
 214                                 uni_stat_t uni_stat;
 215                                 char *uni_dev = unicode_conv_to_printable(&uni_stat, device);
 216                                 if (uni_stat.unicode_width > 20) {
 217                                         printf("%s\n%20s", uni_dev, "");
 218                                 } else {
 219                                         printf("%s%*s", uni_dev, 20 - (int)uni_stat.unicode_width, "");
 220                                 }
 221                                 free(uni_dev);
 222                         }
 223 #else
 224                         if (printf("\n%-20s" + 1, device) > 20)
 225                                     printf("\n%-20s", "");
 226 #endif
 227
 228 #if ENABLE_FEATURE_HUMAN_READABLE
 229                         printf(" %9s ",
 230                                 /* f_blocks x f_bsize / df_disp_hr, show one fractional,
 231                                  * use suffixes if df_disp_hr == 0 */
 232                                 make_human_readable_str(s.f_blocks, s.f_bsize, df_disp_hr));
 233
 234                         printf(" %9s " + 1,
 235                                 /* EXPR x f_bsize / df_disp_hr, show one fractional,
 236                                  * use suffixes if df_disp_hr == 0 */
 237                                 make_human_readable_str((s.f_blocks - s.f_bfree),
 238                                                 s.f_bsize, df_disp_hr));
 239
 240                         printf("%9s %3u%% %s\n",
 241                                 /* f_bavail x f_bsize / df_disp_hr, show one fractional,
 242                                  * use suffixes if df_disp_hr == 0 */
 243                                 make_human_readable_str(s.f_bavail, s.f_bsize, df_disp_hr),
 244                                 blocks_percent_used, mount_point);
 245 #else
 246                         printf(" %9lu %9lu %9lu %3u%% %s\n",
 247                                 kscale(s.f_blocks, s.f_bsize),
 248                                 kscale(s.f_blocks - s.f_bfree, s.f_bsize),
 249                                 kscale(s.f_bavail, s.f_bsize),
 250                                 blocks_percent_used, mount_point);
 251 #endif
 252                 }
 253         }
 254
 255         return status;
 256 }