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 -- options -P and -t missing.  Also blocksize. */
  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
  21 #include <mntent.h>
  22 #include <sys/vfs.h>
  23 #include "libbb.h"
  24
  25 #if !ENABLE_FEATURE_HUMAN_READABLE
  26 static unsigned long kscale(unsigned long b, unsigned long bs)
  27 {
  28         return (b * (unsigned long long) bs + 1024/2) / 1024;
  29 }
  30 #endif
  31
  32 int df_main(int argc, char **argv);
  33 int df_main(int argc, char **argv)
  34 {
  35         unsigned long blocks_used;
  36         unsigned blocks_percent_used;
  37 #if ENABLE_FEATURE_HUMAN_READABLE
  38         unsigned df_disp_hr = 1024;
  39 #endif
  40         int status = EXIT_SUCCESS;
  41         unsigned opt;
  42         FILE *mount_table;
  43         struct mntent *mount_entry;
  44         struct statfs s;
  45         /* default display is kilobytes */
  46         const char *disp_units_hdr = "1k-blocks";
  47
  48 #if ENABLE_FEATURE_HUMAN_READABLE
  49         opt_complementary = "h-km:k-hm:m-hk";
  50         opt = getopt32(argc, argv, "hmk");
  51         if (opt & 1) {
  52                 df_disp_hr = 0;
  53                 disp_units_hdr = "     Size";
  54         }
  55         if (opt & 2) {
  56                 df_disp_hr = 1024*1024;
  57                 disp_units_hdr = "1M-blocks";
  58         }
  59 #else
  60         opt = getopt32(argc, argv, "k");
  61 #endif
  62
  63         printf("Filesystem%11s%-15sUsed Available Use%% Mounted on\n",
  64                           "", disp_units_hdr);
  65
  66         mount_table = NULL;
  67         argv += optind;
  68         if (optind >= argc) {
  69                 mount_table = setmntent(bb_path_mtab_file, "r");
  70                 if (!mount_table) {
  71                         bb_perror_msg_and_die(bb_path_mtab_file);
  72                 }
  73         }
  74
  75         while (1) {
  76                 const char *device;
  77                 const char *mount_point;
  78
  79                 if (mount_table) {
  80                         mount_entry = getmntent(mount_table);
  81                         if (!mount_entry) {
  82                                 endmntent(mount_table);
  83                                 break;
  84                         }
  85                 } else {
  86                         mount_point = *argv++;
  87                         if (!mount_point) {
  88                                 break;
  89                         }
  90                         mount_entry = find_mount_point(mount_point, bb_path_mtab_file);
  91                         if (!mount_entry) {
  92                                 bb_error_msg("%s: can't find mount point", mount_point);
  93  SET_ERROR:
  94                                 status = EXIT_FAILURE;
  95                                 continue;
  96                         }
  97                 }
  98
  99                 device = mount_entry->mnt_fsname;
 100                 mount_point = mount_entry->mnt_dir;
 101
 102                 if (statfs(mount_point, &s) != 0) {
 103                         bb_perror_msg("%s", mount_point);
 104                         goto SET_ERROR;
 105                 }
 106
 107                 if ((s.f_blocks > 0) || !mount_table){
 108                         blocks_used = s.f_blocks - s.f_bfree;
 109                         blocks_percent_used = 0;
 110                         if (blocks_used + s.f_bavail) {
 111                                 blocks_percent_used = (blocks_used * 100ULL
 112                                                 + (blocks_used + s.f_bavail)/2
 113                                                 ) / (blocks_used + s.f_bavail);
 114                         }
 115
 116                         if (strcmp(device, "rootfs") == 0) {
 117                                 continue;
 118                         } else if (strcmp(device, "/dev/root") == 0) {
 119                                 /* Adjusts device to be the real root device,
 120                                 * or leaves device alone if it can't find it */
 121                                 device = find_block_device("/");
 122                                 if (!device) {
 123                                         goto SET_ERROR;
 124                                 }
 125                         }
 126
 127                         if (printf("\n%-20s" + 1, device) > 20)
 128                                     printf("\n%-20s", "");
 129 #if ENABLE_FEATURE_HUMAN_READABLE
 130                         printf(" %9s ",
 131                                 make_human_readable_str(s.f_blocks, s.f_bsize, df_disp_hr));
 132
 133                         printf(" %9s " + 1,
 134                                 make_human_readable_str((s.f_blocks - s.f_bfree),
 135                                                 s.f_bsize, df_disp_hr));
 136
 137                         printf("%9s %3u%% %s\n",
 138                                         make_human_readable_str(s.f_bavail, s.f_bsize, df_disp_hr),
 139                                         blocks_percent_used, mount_point);
 140 #else
 141                         printf(" %9lu %9lu %9lu %3u%% %s\n",
 142                                         kscale(s.f_blocks, s.f_bsize),
 143                                         kscale(s.f_blocks-s.f_bfree, s.f_bsize),
 144                                         kscale(s.f_bavail, s.f_bsize),
 145                                         blocks_percent_used, mount_point);
 146 #endif
 147                 }
 148         }
 149
 150         fflush_stdout_and_exit(status);
 151 }