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 + 1024/2 ) / 1024;
  33 }
  34 #endif
  35
  36 int df_main(int argc, char **argv);
  37 int df_main(int argc, char **argv)
  38 {
  39         long blocks_used;
  40         long blocks_percent_used;
  41 #ifdef CONFIG_FEATURE_HUMAN_READABLE
  42         unsigned long df_disp_hr = 1024;
  43 #endif
  44         int status = EXIT_SUCCESS;
  45         unsigned opt;
  46         FILE *mount_table;
  47         struct mntent *mount_entry;
  48         struct statfs s;
  49         static const char hdr_1k[] = "1k-blocks"; /* default display is kilobytes */
  50         const char *disp_units_hdr = hdr_1k;
  51
  52 #ifdef CONFIG_FEATURE_HUMAN_READABLE
  53         opt_complementary = "h-km:k-hm:m-hk";
  54         opt = getopt32(argc, argv, "hmk");
  55         if (opt & 1) {
  56                 df_disp_hr = 0;
  57                 disp_units_hdr = "     Size";
  58         }
  59         if (opt & 2) {
  60                 df_disp_hr = 1024*1024;
  61                 disp_units_hdr = "1M-blocks";
  62         }
  63 #else
  64         opt = getopt32(argc, argv, "k");
  65 #endif
  66
  67         printf("Filesystem%11s%-15sUsed Available Use%% Mounted on\n",
  68                           "", disp_units_hdr);
  69
  70         mount_table = NULL;
  71         argv += optind;
  72         if (optind >= argc) {
  73                 mount_table = setmntent(bb_path_mtab_file, "r");
  74                 if (!mount_table) {
  75                         bb_perror_msg_and_die(bb_path_mtab_file);
  76                 }
  77         }
  78
  79         do {
  80                 const char *device;
  81                 const char *mount_point;
  82
  83                 if (mount_table) {
  84                         mount_entry = getmntent(mount_table);
  85                         if (!mount_entry) {
  86                                 endmntent(mount_table);
  87                                 break;
  88                         }
  89                 } else {
  90                         mount_point = *argv++;
  91                         if (!mount_point) {
  92                                 break;
  93                         }
  94                         mount_entry = find_mount_point(mount_point, bb_path_mtab_file);
  95                         if (!mount_entry) {
  96                                 bb_error_msg("%s: can't find mount point", mount_point);
  97  SET_ERROR:
  98                                 status = EXIT_FAILURE;
  99                                 continue;
 100                         }
 101                 }
 102
 103                 device = mount_entry->mnt_fsname;
 104                 mount_point = mount_entry->mnt_dir;
 105
 106                 if (statfs(mount_point, &s) != 0) {
 107                         bb_perror_msg("%s", mount_point);
 108                         goto SET_ERROR;
 109                 }
 110
 111                 if ((s.f_blocks > 0) || !mount_table){
 112                         blocks_used = s.f_blocks - s.f_bfree;
 113                         blocks_percent_used = 0;
 114                         if (blocks_used + s.f_bavail) {
 115                                 blocks_percent_used = (((long long) blocks_used) * 100
 116                                                 + (blocks_used + s.f_bavail)/2
 117                                                 ) / (blocks_used + s.f_bavail);
 118                         }
 119
 120                         if (strcmp(device, "rootfs") == 0) {
 121                                 continue;
 122                         } else if (strcmp(device, "/dev/root") == 0) {
 123                                 /* Adjusts device to be the real root device,
 124                                 * or leaves device alone if it can't find it */
 125                                 device = find_block_device("/");
 126                                 if (!device) {
 127                                         goto SET_ERROR;
 128                                 }
 129                         }
 130
 131 #ifdef CONFIG_FEATURE_HUMAN_READABLE
 132                         printf("%-20s %9s ", device,
 133                                 make_human_readable_str(s.f_blocks, s.f_bsize, df_disp_hr));
 134
 135                         printf("%9s ",
 136                                 make_human_readable_str( (s.f_blocks - s.f_bfree),
 137                                                 s.f_bsize, df_disp_hr));
 138
 139                         printf("%9s %3ld%% %s\n",
 140                                           make_human_readable_str(s.f_bavail, s.f_bsize, df_disp_hr),
 141                                           blocks_percent_used, mount_point);
 142 #else
 143                         printf("%-20s %9ld %9ld %9ld %3ld%% %s\n",
 144                                           device,
 145                                           kscale(s.f_blocks, s.f_bsize),
 146                                           kscale(s.f_blocks-s.f_bfree, s.f_bsize),
 147                                           kscale(s.f_bavail, s.f_bsize),
 148                                           blocks_percent_used, mount_point);
 149 #endif
 150                 }
 151
 152         } while (1);
 153
 154         fflush_stdout_and_exit(status);
 155 }