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 <stdio.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24 #include <unistd.h>
  25 #include <mntent.h>
  26 #include <sys/vfs.h>
  27 #include "busybox.h"
  28
  29 #ifndef CONFIG_FEATURE_HUMAN_READABLE
  30 static long kscale(long b, long bs)
  31 {
  32         return ( b * (long long) bs + KILOBYTE/2 ) / KILOBYTE;
  33 }
  34 #endif
  35
  36 int df_main(int argc, char **argv)
  37 {
  38         long blocks_used;
  39         long blocks_percent_used;
  40 #ifdef CONFIG_FEATURE_HUMAN_READABLE
  41         unsigned long df_disp_hr = KILOBYTE;
  42 #endif
  43         int status = EXIT_SUCCESS;
  44         unsigned opt;
  45         FILE *mount_table;
  46         struct mntent *mount_entry;
  47         struct statfs s;
  48         static const char hdr_1k[] = "1k-blocks"; /* default display is kilobytes */
  49         const char *disp_units_hdr = hdr_1k;
  50
  51 #ifdef CONFIG_FEATURE_HUMAN_READABLE
  52         opt_complementary = "h-km:k-hm:m-hk";
  53         opt = getopt32(argc, argv, "hmk");
  54         if(opt & 1) {
  55                                 df_disp_hr = 0;
  56                                 disp_units_hdr = "     Size";
  57         }
  58         if(opt & 2) {
  59                                 df_disp_hr = MEGABYTE;
  60                                 disp_units_hdr = "1M-blocks";
  61         }
  62 #else
  63         opt = getopt32(argc, argv, "k");
  64 #endif
  65
  66         bb_printf("Filesystem%11s%-15sUsed Available Use%% Mounted on\n",
  67                           "", disp_units_hdr);
  68
  69         mount_table = NULL;
  70         argv += optind;
  71         if (optind >= argc) {
  72                 if (!(mount_table = setmntent(bb_path_mtab_file, "r"))) {
  73                         bb_perror_msg_and_die(bb_path_mtab_file);
  74                 }
  75         }
  76
  77         do {
  78                 const char *device;
  79                 const char *mount_point;
  80
  81                 if (mount_table) {
  82                         if (!(mount_entry = getmntent(mount_table))) {
  83                                 endmntent(mount_table);
  84                                 break;
  85                         }
  86                 } else {
  87                         if (!(mount_point = *argv++)) {
  88                                 break;
  89                         }
  90                         if (!(mount_entry = find_mount_point(mount_point, bb_path_mtab_file))) {
  91                                 bb_error_msg("%s: can't find mount point.", mount_point);
  92                         SET_ERROR:
  93                                 status = EXIT_FAILURE;
  94                                 continue;
  95                         }
  96                 }
  97
  98                 device = mount_entry->mnt_fsname;
  99                 mount_point = mount_entry->mnt_dir;
 100
 101                 if (statfs(mount_point, &s) != 0) {
 102                         bb_perror_msg("%s", mount_point);
 103                         goto SET_ERROR;
 104                 }
 105
 106                 if ((s.f_blocks > 0) || !mount_table){
 107                         blocks_used = s.f_blocks - s.f_bfree;
 108                         blocks_percent_used = 0;
 109                         if (blocks_used + s.f_bavail) {
 110                                 blocks_percent_used = (((long long) blocks_used) * 100
 111                                                                            + (blocks_used + s.f_bavail)/2
 112                                                                            ) / (blocks_used + s.f_bavail);
 113                         }
 114
 115                         if (strcmp(device, "rootfs") == 0) {
 116                                 continue;
 117                         } else if (strcmp(device, "/dev/root") == 0) {
 118                                 /* Adjusts device to be the real root device,
 119                                 * or leaves device alone if it can't find it */
 120                                 if ((device = find_block_device("/")) == NULL) {
 121                                         goto SET_ERROR;
 122                                 }
 123                         }
 124
 125 #ifdef CONFIG_FEATURE_HUMAN_READABLE
 126                         bb_printf("%-20s %9s ", device,
 127                                           make_human_readable_str(s.f_blocks, s.f_bsize, df_disp_hr));
 128
 129                         bb_printf("%9s ",
 130                                           make_human_readable_str( (s.f_blocks - s.f_bfree),
 131                                                                                           s.f_bsize, df_disp_hr));
 132
 133                         bb_printf("%9s %3ld%% %s\n",
 134                                           make_human_readable_str(s.f_bavail, s.f_bsize, df_disp_hr),
 135                                           blocks_percent_used, mount_point);
 136 #else
 137                         bb_printf("%-20s %9ld %9ld %9ld %3ld%% %s\n",
 138                                           device,
 139                                           kscale(s.f_blocks, s.f_bsize),
 140                                           kscale(s.f_blocks-s.f_bfree, s.f_bsize),
 141                                           kscale(s.f_bavail, s.f_bsize),
 142                                           blocks_percent_used, mount_point);
 143 #endif
 144                 }
 145
 146         } while (1);
 147
 148         bb_fflush_stdout_and_exit(status);
 149 }