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