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 tarball for details.
   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 #include <mntent.h>
  26 #include <sys/vfs.h>
  27 #include "libbb.h"
  28 #include "unicode.h"
  29
  30 #if !ENABLE_FEATURE_HUMAN_READABLE
  31 static unsigned long kscale(unsigned long b, unsigned long bs)
  32 {
  33         return (b * (unsigned long long) bs + 1024/2) / 1024;
  34 }
  35 #endif
  36
  37 int df_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  38 int df_main(int argc UNUSED_PARAM, char **argv)
  39 {
  40         unsigned long blocks_used;
  41         unsigned blocks_percent_used;
  42         unsigned long df_disp_hr = 1024;
  43         int status = EXIT_SUCCESS;
  44         unsigned opt;
  45         FILE *mount_table;
  46         struct mntent *mount_entry;
  47         struct statfs s;
  48
  49         enum {
  50                 OPT_KILO  = (1 << 0),
  51                 OPT_POSIX = (1 << 1),
  52                 OPT_ALL   = (1 << 2) * ENABLE_FEATURE_DF_FANCY,
  53                 OPT_INODE = (1 << 3) * ENABLE_FEATURE_DF_FANCY,
  54                 OPT_BSIZE = (1 << 4) * ENABLE_FEATURE_DF_FANCY,
  55                 OPT_HUMAN = (1 << (2 + 3*ENABLE_FEATURE_DF_FANCY)) * ENABLE_FEATURE_HUMAN_READABLE,
  56                 OPT_MEGA  = (1 << (3 + 3*ENABLE_FEATURE_DF_FANCY)) * ENABLE_FEATURE_HUMAN_READABLE,
  57         };
  58         const char *disp_units_hdr = NULL;
  59         char *chp;
  60
  61         init_unicode();
  62
  63 #if ENABLE_FEATURE_HUMAN_READABLE && ENABLE_FEATURE_DF_FANCY
  64         opt_complementary = "k-mB:m-Bk:B-km";
  65 #elif ENABLE_FEATURE_HUMAN_READABLE
  66         opt_complementary = "k-m:m-k";
  67 #endif
  68         opt = getopt32(argv, "kP"
  69                         IF_FEATURE_DF_FANCY("aiB:")
  70                         IF_FEATURE_HUMAN_READABLE("hm")
  71                         IF_FEATURE_DF_FANCY(, &chp));
  72         if (opt & OPT_MEGA)
  73                 df_disp_hr = 1024*1024;
  74
  75         if (opt & OPT_BSIZE)
  76                 df_disp_hr = xatoul_range(chp, 1, ULONG_MAX); /* disallow 0 */
  77
  78         /* From the manpage of df from coreutils-6.10:
  79            Disk space is shown in 1K blocks by default, unless the environment
  80            variable POSIXLY_CORRECT is set, in which case 512-byte blocks are used.
  81         */
  82         if (getenv("POSIXLY_CORRECT")) /* TODO - a new libbb function? */
  83                 df_disp_hr = 512;
  84
  85         if (opt & OPT_HUMAN) {
  86                 df_disp_hr = 0;
  87                 disp_units_hdr = "     Size";
  88         }
  89         if (opt & OPT_INODE)
  90                 disp_units_hdr = "   Inodes";
  91
  92         if (disp_units_hdr == NULL) {
  93 #if ENABLE_FEATURE_HUMAN_READABLE
  94                 disp_units_hdr = xasprintf("%s-blocks",
  95                         /* print df_disp_hr, show no fractionals,
  96                          * use suffixes if OPT_POSIX is set in opt */
  97                         make_human_readable_str(df_disp_hr, 0, !!(opt & OPT_POSIX))
  98                 );
  99 #else
 100                 disp_units_hdr = xasprintf("%lu-blocks", df_disp_hr);
 101 #endif
 102         }
 103         printf("Filesystem           %-15sUsed Available %s Mounted on\n",
 104                         disp_units_hdr, (opt & OPT_POSIX) ? "Capacity" : "Use%");
 105
 106         mount_table = NULL;
 107         argv += optind;
 108         if (!argv[0]) {
 109                 mount_table = setmntent(bb_path_mtab_file, "r");
 110                 if (!mount_table)
 111                         bb_perror_msg_and_die(bb_path_mtab_file);
 112         }
 113
 114         while (1) {
 115                 const char *device;
 116                 const char *mount_point;
 117 #if ENABLE_FEATURE_ASSUME_UNICODE
 118                 size_t dev_len;
 119 #endif
 120
 121                 if (mount_table) {
 122                         mount_entry = getmntent(mount_table);
 123                         if (!mount_entry) {
 124                                 endmntent(mount_table);
 125                                 break;
 126                         }
 127                 } else {
 128                         mount_point = *argv++;
 129                         if (!mount_point)
 130                                 break;
 131                         mount_entry = find_mount_point(mount_point, 1);
 132                         if (!mount_entry) {
 133                                 bb_error_msg("%s: can't find mount point", mount_point);
 134  set_error:
 135                                 status = EXIT_FAILURE;
 136                                 continue;
 137                         }
 138                 }
 139
 140                 device = mount_entry->mnt_fsname;
 141                 mount_point = mount_entry->mnt_dir;
 142
 143                 if (statfs(mount_point, &s) != 0) {
 144                         bb_simple_perror_msg(mount_point);
 145                         goto set_error;
 146                 }
 147
 148                 if ((s.f_blocks > 0) || !mount_table || (opt & OPT_ALL)) {
 149                         if (opt & OPT_INODE) {
 150                                 s.f_blocks = s.f_files;
 151                                 s.f_bavail = s.f_bfree = s.f_ffree;
 152                                 s.f_bsize = 1;
 153
 154                                 if (df_disp_hr)
 155                                         df_disp_hr = 1;
 156                         }
 157                         blocks_used = s.f_blocks - s.f_bfree;
 158                         blocks_percent_used = 0;
 159                         if (blocks_used + s.f_bavail) {
 160                                 blocks_percent_used = (blocks_used * 100ULL
 161                                                 + (blocks_used + s.f_bavail)/2
 162                                                 ) / (blocks_used + s.f_bavail);
 163                         }
 164
 165                         /* GNU coreutils 6.10 skips certain mounts, try to be compatible.  */
 166                         if (strcmp(device, "rootfs") == 0)
 167                                 continue;
 168
 169 #ifdef WHY_WE_DO_IT_FOR_DEV_ROOT_ONLY
 170                         if (strcmp(device, "/dev/root") == 0) {
 171                                 /* Adjusts device to be the real root device,
 172                                  * or leaves device alone if it can't find it */
 173                                 device = find_block_device("/");
 174                                 if (!device) {
 175                                         goto set_error;
 176                                 }
 177                         }
 178 #endif
 179
 180 #if ENABLE_FEATURE_ASSUME_UNICODE
 181                         dev_len = unicode_strlen(device);
 182                         if (dev_len > 20) {
 183                                 printf("%s\n%20s", device, "");
 184                         } else {
 185                                 printf("%s%*s", device, 20 - (int)dev_len, "");
 186                         }
 187 #else
 188                         if (printf("\n%-20s" + 1, device) > 20)
 189                                     printf("\n%-20s", "");
 190 #endif
 191
 192 #if ENABLE_FEATURE_HUMAN_READABLE
 193                         printf(" %9s ",
 194                                 /* f_blocks x f_bsize / df_disp_hr, show one fractional,
 195                                  * use suffixes if df_disp_hr == 0 */
 196                                 make_human_readable_str(s.f_blocks, s.f_bsize, df_disp_hr));
 197
 198                         printf(" %9s " + 1,
 199                                 /* EXPR x f_bsize / df_disp_hr, show one fractional,
 200                                  * use suffixes if df_disp_hr == 0 */
 201                                 make_human_readable_str((s.f_blocks - s.f_bfree),
 202                                                 s.f_bsize, df_disp_hr));
 203
 204                         printf("%9s %3u%% %s\n",
 205                                 /* f_bavail x f_bsize / df_disp_hr, show one fractional,
 206                                  * use suffixes if df_disp_hr == 0 */
 207                                 make_human_readable_str(s.f_bavail, s.f_bsize, df_disp_hr),
 208                                 blocks_percent_used, mount_point);
 209 #else
 210                         printf(" %9lu %9lu %9lu %3u%% %s\n",
 211                                 kscale(s.f_blocks, s.f_bsize),
 212                                 kscale(s.f_blocks - s.f_bfree, s.f_bsize),
 213                                 kscale(s.f_bavail, s.f_bsize),
 214                                 blocks_percent_used, mount_point);
 215 #endif
 216                 }
 217         }
 218
 219         return status;
 220 }