man1/df.1

   1 .\" Copyright Andries Brouwer, Ragnar Hojland Espinosa and A. Wik, 1998.
   2 .\"
   3 .\" This file may be copied under the conditions described
   4 .\" in the LDP GENERAL PUBLIC LICENSE, Version 1, September 1998
   5 .\" that should have been distributed together with this file.
   6 .\"
   7 .TH DF 1 1998-11 "GNU fileutils 4.0"
   8 .SH NAME
   9 df \- report filesystem disk space usage
  10 .SH SYNOPSIS
  11 .BI "df [" options "] [" file... ]
  12 .sp
  13 POSIX options:
  14 .B "[\-kP] [\-\-]"
  15 .sp
  16 GNU options (shortest form):
  17 .B [\-ahHiklmPv]
  18 .BI "[\-t " fstype ]
  19 .BI "[\-x " fstype ]
  20 .BI "[\-\-block\-size=" size ]
  21 .B [\-\-print\-type]
  22 .B [\-\-no\-sync]
  23 .B [\-\-sync]
  24 .B "[\-\-help] [\-\-version] [\-\-]"
  25 .SH DESCRIPTION
  26 .B df
  27 reports the amount of disk space used and available on
  28 filesystems.
  29 .PP
  30 With no arguments,
  31 .B df
  32 reports the space used and available on all
  33 currently mounted filesystems (of all types).
  34 Otherwise,
  35 .B df
  36 reports on the filesystem containing each argument
  37 .IR file .
  38 .SH "POSIX DETAILS"
  39 The output is in 512-byte units by default, but in
  40 1024-byte units when the \-k option is given.
  41 The output format is undefined, unless the \-P option is given.
  42 If
  43 .I file
  44 is not a regular file, a directory or a FIFO, the result
  45 is unspecified.
  46 .SH "GNU DETAILS"
  47 The output is in 1024-byte units (when no units are
  48 specified by options), unless the environment variable
  49 .B POSIXLY_CORRECT
  50 is set, in which case POSIX is followed.
  51 .PP
  52 If an argument
  53 .I file
  54 is a disk device file containing a mounted filesystem,
  55 .B df
  56 shows the space available on that filesystem rather
  57 than on the filesystem containing the device node.
  58 .SH "POSIX OPTIONS"
  59 .TP
  60 .B "\-k"
  61 Use 1024-byte units instead of the default 512-byte units.
  62 .TP
  63 .B "\-P"
  64 Output in six columns, with heading `Filesystem N-blocks
  65 Used Available Capacity Mounted on' (with N=512, but N=1024
  66 when the \-k option is given).
  67 .TP
  68 .B "\-\-"
  69 Terminate option list.
  70 .SH "GNU OPTIONS"
  71 .TP
  72 .B "\-a, \-\-all"
  73 Include in the listing filesystems that have a size of 0 blocks,
  74 which are omitted by default.  Such filesystems are typically
  75 special-purpose pseudo-filesystems, such as automounter entries.
  76 Also, filesystems of type "ignore" or "auto", supported by some
  77 operating systems, are only included if this option is specified.
  78 .TP
  79 .BI "\-\-block\-size=" size
  80 Print sizes in blocks of
  81 .I size
  82 bytes. (New but broken in fileutils-4.0.)
  83 .TP
  84 .B "\-h, \-\-human\-readable"
  85 Append a size letter such as
  86 .B M
  87 for binary megabytes (`mebibytes') to each size.
  88 .TP
  89 .B "\-H, \-\-si"
  90 Do the same as for
  91 .BR \-h ,
  92 but use the official SI units (with powers of 1000 instead of 1024,
  93 so that M stands for 1000000 instead of 1048576).
  94 (New in fileutils-4.0.)
  95 .TP
  96 .B "\-i, \-\-inodes"
  97 List inode usage information instead of block usage.  An inode
  98 (short for index node) contains information about a file such
  99 as its owner, permissions, timestamps, and location on the disk.
 100 .TP
 101 .B "\-k, \-\-kilobytes"
 102 Print sizes in 1024-byte blocks.
 103 .TP
 104 .B "\-l, \-\-local"
 105 Limit the output to local filesystems only.
 106 (New in fileutils-4.0.)
 107 .TP
 108 .B "\-m, \-\-megabytes"
 109 Print sizes in binary megabyte (that's 1048576 bytes) blocks.
 110 Note that the four options \-h, \-H, \-k, \-m are mutually exclusive
 111 and only the last one is effective; for example, it is not the case
 112 that giving both the \-\-si and \-m options would result in output
 113 in (actual, 1000000-byte) megabytes. [The interpretation of blocksizes
 114 is also influenced by the environment variable BLOCK_SIZE, but this
 115 does not work in the fileutils-4.0 version.]
 116 .TP
 117 .B "\-\-no\-sync"
 118 Do not invoke the
 119 .B sync
 120 system call before getting any usage data.
 121 This may make
 122 .B df
 123 run significantly faster, but on some systems (notably SunOS)
 124 the results may be slightly out of date.  This is the default.
 125 .TP
 126 .B "\-P, \-\-portability"
 127 Use the
 128 .SM POSIX
 129 output format.  This is like the default format
 130 except that the information about each filesystem is always
 131 printed on exactly one line; a mount device is never put on a line
 132 by itself.  This means that if the mount device name is more than
 133 20 characters long (e.g., for some network mounts), the columns
 134 are misaligned.
 135 .TP
 136 .B "\-\-sync"
 137 Invoke the
 138 .B sync
 139 system call before getting any usage data.  On some systems
 140 (notably SunOS), doing this yields more up to date results,
 141 but in general this option makes
 142 .B df
 143 much slower, especially when there are many or very busy filesystems.
 144 .TP
 145 .BI "\-t " "fstype, " "\-\-type=" "fstype"
 146 Limit the listing to filesystems of type
 147 .IR fstype .
 148 Multiple filesystem types can be specified by giving multiple
 149 .B \-t
 150 options. By default, nothing is omitted.
 151 .TP
 152 .B "\-T, \-\-print\-type"
 153 Print each filesystem's type.
 154 The types given are those reported by the system
 155 (and are found in a system-dependent way, for example by reading
 156 .IR /etc/mtab ).
 157 See also
 158 .BR mount (8).
 159 .TP
 160 .BI "\-x " "fstype, " "\-\-exclude\-type=" "fstype"
 161 Limit the listing to filesystems not of type
 162 .I fstype.
 163 Multiple filesystem types can be eliminated by giving multiple
 164 .B "\-x"
 165 options.  By default, no filesystem types are omitted.
 166 .TP
 167 .B "\-v"
 168 Ignored; for compatibility with System V versions of
 169 .B df.
 170 .SH "GNU STANDARD OPTIONS"
 171 .TP
 172 .B "\-\-help"
 173 Print a usage message on standard output and exit successfully.
 174 .TP
 175 .B "\-\-version"
 176 Print version information on standard output, then exit successfully.
 177 .TP
 178 .B "\-\-"
 179 Terminate option list.
 180 .SH ENVIRONMENT
 181 The variable POSIXLY_CORRECT determines the choice of unit.
 182 If it is not set, and the variable BLOCKSIZE has a value starting
 183 with `HUMAN', then behaviour is as for the \-h option,
 184 unless overridden by \-k or \-m options.
 185 The variables LANG, LC_ALL, LC_CTYPE and LC_MESSAGES have the
 186 usual meaning.
 187 .SH "CONFORMING TO"
 188 POSIX 1003.2
 189 .SH "SEE ALSO"
 190 .BR mount (8)
 191 .SH NOTES
 192 This page describes
 193 .B df
 194 as found in the fileutils-4.0 package;
 195 other versions may differ slightly.