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
  29 #if !ENABLE_FEATURE_HUMAN_READABLE
  30 static unsigned long kscale(unsigned long b, unsigned long bs)
  31 {
  32         return (b * (unsigned long long) bs + 1024/2) / 1024;
  33 }
  34 #endif
  35
  36 int df_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  37 int df_main(int argc, char **argv)
  38 {
  39         unsigned long blocks_used;
  40         unsigned blocks_percent_used;
  41         unsigned long df_disp_hr = 1024;
  42         int status = EXIT_SUCCESS;
  43         unsigned opt;
  44         FILE *mount_table;
  45         struct mntent *mount_entry;
  46         struct statfs s;
  47         static const char ignored_mounts[] ALIGN1 =
  48           "rootfs\0";
  49
  50         enum {
  51                 OPT_KILO  = (1 << 0),
  52                 OPT_POSIX = (1 << 1),
  53                 OPT_ALL   = (1 << 2) * ENABLE_FEATURE_DF_FANCY,
  54                 OPT_INODE = (1 << 3) * ENABLE_FEATURE_DF_FANCY,
  55                 OPT_BSIZE = (1 << 4) * ENABLE_FEATURE_DF_FANCY,
  56                 OPT_HUMAN = (1 << 5) * ENABLE_FEATURE_HUMAN_READABLE,
  57                 OPT_MEGA  = (1 << 6) * ENABLE_FEATURE_HUMAN_READABLE,
  58         };
  59         const char *disp_units_hdr = NULL;
  60         char *chp;
  61
  62 #if ENABLE_FEATURE_HUMAN_READABLE && ENABLE_FEATURE_DF_FANCY
  63         opt_complementary = "k-mB:m-Bk:B-km";
  64 #elif ENABLE_FEATURE_HUMAN_READABLE
  65         opt_complementary = "k-m:m-k";
  66 #endif
  67         opt = getopt32(argv, "kP"
  68                         USE_FEATURE_DF_FANCY("aiB:")
  69                         USE_FEATURE_HUMAN_READABLE("hm")
  70                         USE_FEATURE_DF_FANCY(, &chp));
  71         if (opt & OPT_MEGA)
  72                 df_disp_hr = 1024*1024;
  73
  74         if (opt & OPT_BSIZE)
  75                 df_disp_hr = xatoul_range(chp, 1, ULONG_MAX); /* disallow 0 */
  76
  77         /* From the manpage of df from coreutils-6.10:
  78            Disk space is shown in 1K blocks by default, unless the environment
  79            variable POSIXLY_CORRECT is set, in which case 512-byte blocks are used.
  80         */
  81         if (getenv("POSIXLY_CORRECT")) /* TODO - a new libbb function? */
  82                 df_disp_hr = 512;
  83
  84         if (opt & OPT_HUMAN) {
  85                 df_disp_hr = 0;
  86                 disp_units_hdr = "     Size";
  87         }
  88         if (opt & OPT_INODE)
  89                 disp_units_hdr = "   Inodes";
  90
  91         if (disp_units_hdr == NULL) {
  92 #if ENABLE_FEATURE_HUMAN_READABLE
  93                 disp_units_hdr = xasprintf("%s-blocks",
  94                         make_human_readable_str(df_disp_hr, 0, !!(opt & OPT_POSIX)));
  95 #else
  96                 disp_units_hdr = xasprintf("%lu-blocks", df_disp_hr);
  97 #endif
  98         }
  99         printf("Filesystem           %-15sUsed Available %s Mounted on\n",
 100                         disp_units_hdr, (opt & OPT_POSIX) ? "Capacity" : "Use%");
 101
 102         mount_table = NULL;
 103         argv += optind;
 104         if (optind >= argc) {
 105                 mount_table = setmntent(bb_path_mtab_file, "r");
 106                 if (!mount_table)
 107                         bb_perror_msg_and_die(bb_path_mtab_file);
 108         }
 109
 110         while (1) {
 111                 const char *device;
 112                 const char *mount_point;
 113
 114                 if (mount_table) {
 115                         mount_entry = getmntent(mount_table);
 116                         if (!mount_entry) {
 117                                 endmntent(mount_table);
 118                                 break;
 119                         }
 120                 } else {
 121                         mount_point = *argv++;
 122                         if (!mount_point)
 123                                 break;
 124                         mount_entry = find_mount_point(mount_point, bb_path_mtab_file);
 125                         if (!mount_entry) {
 126                                 bb_error_msg("%s: can't find mount point", mount_point);
 127  SET_ERROR:
 128                                 status = EXIT_FAILURE;
 129                                 continue;
 130                         }
 131                 }
 132
 133                 device = mount_entry->mnt_fsname;
 134                 mount_point = mount_entry->mnt_dir;
 135
 136                 if (statfs(mount_point, &s) != 0) {
 137                         bb_simple_perror_msg(mount_point);
 138                         goto SET_ERROR;
 139                 }
 140
 141                 if ((s.f_blocks > 0) || !mount_table || (opt & OPT_ALL)) {
 142                         if (opt & OPT_INODE) {
 143                                 s.f_blocks = s.f_files;
 144                                 s.f_bavail = s.f_bfree = s.f_ffree;
 145                                 s.f_bsize = 1;
 146
 147                                 if (df_disp_hr)
 148                                         df_disp_hr = 1;
 149                         }
 150                         blocks_used = s.f_blocks - s.f_bfree;
 151                         blocks_percent_used = 0;
 152                         if (blocks_used + s.f_bavail) {
 153                                 blocks_percent_used = (blocks_used * 100ULL
 154                                                 + (blocks_used + s.f_bavail)/2
 155                                                 ) / (blocks_used + s.f_bavail);
 156                         }
 157
 158                         /* GNU coreutils 6.10 skip certain mounts, try to be compatible.  */
 159                         if (index_in_strings(device, ignored_mounts) != -1)
 160                                 continue;
 161
 162 #ifdef WHY_WE_DO_IT_FOR_DEV_ROOT_ONLY
 163 /* ... and also this is the only user of find_block_device */
 164                         if (strcmp(device, "/dev/root") == 0) {
 165                                 /* Adjusts device to be the real root device,
 166                                 * or leaves device alone if it can't find it */
 167                                 device = find_block_device("/");
 168                                 if (!device) {
 169                                         goto SET_ERROR;
 170                                 }
 171                         }
 172 #endif
 173
 174                         if (printf("\n%-20s" + 1, device) > 20)
 175                                     printf("\n%-20s", "");
 176 #if ENABLE_FEATURE_HUMAN_READABLE
 177                         printf(" %9s ",
 178                                 make_human_readable_str(s.f_blocks, s.f_bsize, df_disp_hr));
 179
 180                         printf(" %9s " + 1,
 181                                 make_human_readable_str((s.f_blocks - s.f_bfree),
 182                                                 s.f_bsize, df_disp_hr));
 183
 184                         printf("%9s %3u%% %s\n",
 185                                         make_human_readable_str(s.f_bavail, s.f_bsize, df_disp_hr),
 186                                         blocks_percent_used, mount_point);
 187 #else
 188                         printf(" %9lu %9lu %9lu %3u%% %s\n",
 189                                         kscale(s.f_blocks, s.f_bsize),
 190                                         kscale(s.f_blocks - s.f_bfree, s.f_bsize),
 191                                         kscale(s.f_bavail, s.f_bsize),
 192                                         blocks_percent_used, mount_point);
 193 #endif
 194                 }
 195         }
 196
 197         return status;
 198 }