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 #ifndef CONFIG_FEATURE_HUMAN_READABLE
  26 static long kscale(long b, long bs)
  27 {
  28         return ( b * (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         long blocks_used;
  36         long blocks_percent_used;
  37 #ifdef CONFIG_FEATURE_HUMAN_READABLE
  38         unsigned long 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         static const char hdr_1k[] ALIGN1 = "1k-blocks";
  47         const char *disp_units_hdr = hdr_1k;
  48
  49 #ifdef CONFIG_FEATURE_HUMAN_READABLE
  50         opt_complementary = "h-km:k-hm:m-hk";
  51         opt = getopt32(argc, argv, "hmk");
  52         if (opt & 1) {
  53                 df_disp_hr = 0;
  54                 disp_units_hdr = "     Size";
  55         }
  56         if (opt & 2) {
  57                 df_disp_hr = 1024*1024;
  58                 disp_units_hdr = "1M-blocks";
  59         }
  60 #else
  61         opt = getopt32(argc, argv, "k");
  62 #endif
  63
  64         printf("Filesystem%11s%-15sUsed Available Use%% Mounted on\n",
  65                           "", disp_units_hdr);
  66
  67         mount_table = NULL;
  68         argv += optind;
  69         if (optind >= argc) {
  70                 mount_table = setmntent(bb_path_mtab_file, "r");
  71                 if (!mount_table) {
  72                         bb_perror_msg_and_die(bb_path_mtab_file);
  73                 }
  74         }
  75
  76         do {
  77                 const char *device;
  78                 const char *mount_point;
  79
  80                 if (mount_table) {
  81                         mount_entry = getmntent(mount_table);
  82                         if (!mount_entry) {
  83                                 endmntent(mount_table);
  84                                 break;
  85                         }
  86                 } else {
  87                         mount_point = *argv++;
  88                         if (!mount_point) {
  89                                 break;
  90                         }
  91                         mount_entry = find_mount_point(mount_point, bb_path_mtab_file);
  92                         if (!mount_entry) {
  93                                 bb_error_msg("%s: can't find mount point", mount_point);
  94  SET_ERROR:
  95                                 status = EXIT_FAILURE;
  96                                 continue;
  97                         }
  98                 }
  99
 100                 device = mount_entry->mnt_fsname;
 101                 mount_point = mount_entry->mnt_dir;
 102
 103                 if (statfs(mount_point, &s) != 0) {
 104                         bb_perror_msg("%s", mount_point);
 105                         goto SET_ERROR;
 106                 }
 107
 108                 if ((s.f_blocks > 0) || !mount_table){
 109                         blocks_used = s.f_blocks - s.f_bfree;
 110                         blocks_percent_used = 0;
 111                         if (blocks_used + s.f_bavail) {
 112                                 blocks_percent_used = (((long long) blocks_used) * 100
 113                                                 + (blocks_used + s.f_bavail)/2
 114                                                 ) / (blocks_used + s.f_bavail);
 115                         }
 116
 117                         if (strcmp(device, "rootfs") == 0) {
 118                                 continue;
 119                         } else if (strcmp(device, "/dev/root") == 0) {
 120                                 /* Adjusts device to be the real root device,
 121                                 * or leaves device alone if it can't find it */
 122                                 device = find_block_device("/");
 123                                 if (!device) {
 124                                         goto SET_ERROR;
 125                                 }
 126                         }
 127
 128 #ifdef CONFIG_FEATURE_HUMAN_READABLE
 129                         printf("%-20s %9s ", device,
 130                                 make_human_readable_str(s.f_blocks, s.f_bsize, df_disp_hr));
 131
 132                         printf("%9s ",
 133                                 make_human_readable_str( (s.f_blocks - s.f_bfree),
 134                                                 s.f_bsize, df_disp_hr));
 135
 136                         printf("%9s %3ld%% %s\n",
 137                                           make_human_readable_str(s.f_bavail, s.f_bsize, df_disp_hr),
 138                                           blocks_percent_used, mount_point);
 139 #else
 140                         printf("%-20s %9ld %9ld %9ld %3ld%% %s\n",
 141                                           device,
 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         } while (1);
 150
 151         fflush_stdout_and_exit(status);
 152 }