coreutils/df.c

   1 #include "internal.h"
   2 #include <stdio.h>
   3 #include <mntent.h>
   4 #include <sys/stat.h>
   5 #include <sys/vfs.h>
   6
   7 const char      df_usage[] = "df [filesystem ...]\n"
   8 "\n"
   9 "\tPrint the filesystem space used and space available.\n";
  10
  11
  12 static int
  13 df(const char * device, const char * mountPoint)
  14 {
  15         struct statfs   s;
  16         long            blocks_used;
  17         long            blocks_percent_used;
  18
  19         if ( statfs(mountPoint, &s) != 0 ) {
  20                 perror(mountPoint);
  21                 return 1;
  22         }
  23
  24         if ( s.f_blocks > 0 ) {
  25                 blocks_used = s.f_blocks - s.f_bfree;
  26                 blocks_percent_used = (long)
  27                  (blocks_used * 100.0 / (blocks_used + s.f_bavail) + 0.5);
  28
  29 /*
  30                 printf(
  31                  "%-20s %7ld %7ld  %7ld  %5ld%%   %s\n"
  32                 ,device
  33                 ,s.f_blocks
  34                 ,s.f_blocks - s.f_bfree
  35                 ,s.f_bavail
  36                 ,blocks_percent_used
  37                 ,mountPoint);
  38 */
  39
  40                 printf(
  41                        "%-20s %7.0f %7.0f  %7.0f  %5ld%%   %s\n"
  42                        ,device
  43                        ,s.f_blocks * (s.f_bsize / 1024.0)
  44                        ,(s.f_blocks - s.f_bfree)  * (s.f_bsize / 1024.0)
  45                        ,s.f_bavail * (s.f_bsize / 1024.0)
  46                        ,blocks_percent_used
  47                        ,mountPoint);
  48
  49         }
  50
  51         return 0;
  52 }
  53
  54 extern int
  55 df_main(int argc, char * * argv)
  56 {
  57         static const char header[] =
  58          "Filesystem         1024-blocks  Used Available Capacity Mounted on\n";
  59         printf(header);
  60
  61         if ( argc > 1 ) {
  62                 struct mntent * mountEntry;
  63                 int                             status;
  64
  65                 while ( argc > 1 ) {
  66                         if ( (mountEntry = findMountPoint(argv[1], "/proc/mounts")) == 0 )
  67                         {
  68                                 fprintf(stderr, "%s: can't find mount point.\n" ,argv[1]);
  69                                 return 1;
  70                         }
  71                         status = df(mountEntry->mnt_fsname, mountEntry->mnt_dir);
  72                         if ( status != 0 )
  73                                 return status;
  74                         argc--;
  75                         argv++;
  76                 }
  77                 return 0;
  78         }
  79         else {
  80                 FILE *          mountTable;
  81                 struct mntent * mountEntry;
  82
  83                 if ( (mountTable = setmntent("/proc/mounts", "r")) == 0) {
  84                         perror("/proc/mounts");
  85                         return 1;
  86                 }
  87
  88                 while ( (mountEntry = getmntent(mountTable)) != 0 ) {
  89                         int status = df(
  90                          mountEntry->mnt_fsname
  91                         ,mountEntry->mnt_dir);
  92                         if ( status != 0 )
  93                                 return status;
  94                 }
  95                 endmntent(mountTable);
  96         }
  97
  98         return 0;
  99 }
 100
 101
 102
 103
 104 /*
 105  * Given a block device, find the mount table entry if that block device
 106  * is mounted.
 107  *
 108  * Given any other file (or directory), find the mount table entry for its
 109  * filesystem.
 110  */
 111 extern struct mntent *
 112 findMountPoint(const char * name, const char * table)
 113 {
 114         struct stat     s;
 115         dev_t                   mountDevice;
 116         FILE *                  mountTable;
 117         struct mntent * mountEntry;
 118
 119         if ( stat(name, &s) != 0 )
 120                 return 0;
 121
 122         if ( (s.st_mode & S_IFMT) == S_IFBLK )
 123                 mountDevice = s.st_rdev;
 124         else
 125                 mountDevice = s.st_dev;
 126
 127
 128         if ( (mountTable = setmntent(table, "r")) == 0 )
 129                 return 0;
 130
 131         while ( (mountEntry = getmntent(mountTable)) != 0 ) {
 132                 if ( strcmp(name, mountEntry->mnt_dir) == 0
 133                  || strcmp(name, mountEntry->mnt_fsname) == 0 ) /* String match. */
 134                         break;
 135                 if ( stat(mountEntry->mnt_fsname, &s) == 0
 136                  && s.st_rdev == mountDevice )  /* Match the device. */
 137                                 break;
 138                 if ( stat(mountEntry->mnt_dir, &s) == 0
 139                  && s.st_dev == mountDevice )   /* Match the directory's mount point. */
 140                         break;
 141         }
 142         endmntent(mountTable);
 143         return mountEntry;
 144 }