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