Originální popis anglicky:
df - report filesystem disk space usage
Návod, kniha: General Commands Manual
df [options] [file...]
POSIX options:
[-kP] [--]
GNU options (shortest form):
[-ahHiklmPv] [-t
fstype] [-x fstype]
[--block-size=size] [--print-type]
[--no-sync] [--sync] [--help] [--version] [--]
df reports the amount of disk space used and available on filesystems.
With no arguments,
df reports the space used and available on all
currently mounted filesystems (of all types). Otherwise,
df reports on
the filesystem containing each argument
file.
The output is in 512-byte units by default, but in 1024-byte units when the -k
option is given. The output format is undefined, unless the -P option is
given. If
file is not a regular file, a directory or a FIFO, the result
is unspecified.
The output is in 1024-byte units (when no units are specified by options),
unless the environment variable
POSIXLY_CORRECT is set, in which case
POSIX is followed.
If an argument
file is a disk device file containing a mounted
filesystem,
df shows the space available on that filesystem rather than
on the filesystem containing the device node.
- -k
- Use 1024-byte units instead of the default 512-byte
units.
- -P
- Output in six columns, with heading `Filesystem N-blocks
Used Available Capacity Mounted on' (with N=512, but N=1024 when the -k
option is given).
- --
- Terminate option list.
- -a, --all
- Include in the listing filesystems that have a size of 0
blocks, which are omitted by default. Such filesystems are typically
special-purpose pseudo-filesystems, such as automounter entries. Also,
filesystems of type "ignore" or "auto", supported by
some operating systems, are only included if this option is
specified.
- --block-size=size
- Print sizes in blocks of size bytes. (New but broken
in fileutils-4.0.)
- -h, --human-readable
- Append a size letter such as M for binary megabytes
(`mebibytes') to each size.
- -H, --si
- Do the same as for -h, but use the official SI units
(with powers of 1000 instead of 1024, so that M stands for 1000000 instead
of 1048576). (New in fileutils-4.0.)
- -i, --inodes
- List inode usage information instead of block usage. An
inode (short for index node) contains information about a file such as its
owner, permissions, timestamps, and location on the disk.
- -k, --kilobytes
- Print sizes in 1024-byte blocks.
- -l, --local
- Limit the output to local filesystems only. (New in
fileutils-4.0.)
- -m, --megabytes
- Print sizes in binary megabyte (that's 1048576 bytes)
blocks. Note that the four options -h, -H, -k, -m are mutually exclusive
and only the last one is effective; for example, it is not the case that
giving both the --si and -m options would result in output in (actual,
1000000-byte) megabytes. [The interpretation of blocksizes is also
influenced by the environment variable BLOCK_SIZE, but this does not work
in the fileutils-4.0 version.]
- --no-sync
- Do not invoke the sync system call before getting
any usage data. This may make df run significantly faster, but on
some systems (notably SunOS) the results may be slightly out of date. This
is the default.
- -P, --portability
- Use the POSIX output format. This is like
the default format except that the information about each filesystem is
always printed on exactly one line; a mount device is never put on a line
by itself. This means that if the mount device name is more than 20
characters long (e.g., for some network mounts), the columns are
misaligned.
- --sync
- Invoke the sync system call before getting any usage
data. On some systems (notably SunOS), doing this yields more up to date
results, but in general this option makes df much slower,
especially when there are many or very busy filesystems.
- -t fstype, --type=fstype
- Limit the listing to filesystems of type fstype.
Multiple filesystem types can be specified by giving multiple -t
options. By default, nothing is omitted.
- -T, --print-type
- Print each filesystem's type. The types given are those
reported by the system (and are found in a system-dependent way, for
example by reading /etc/mtab). See also mount(8).
- -x fstype,
--exclude-type=fstype
- Limit the listing to filesystems not of type fstype.
Multiple filesystem types can be eliminated by giving multiple -x
options. By default, no filesystem types are omitted.
- -v
- Ignored; for compatibility with System V versions of
df.
- --help
- Print a usage message on standard output and exit
successfully.
- --version
- Print version information on standard output, then exit
successfully.
- --
- Terminate option list.
The variable POSIXLY_CORRECT determines the choice of unit. If it is not set,
and the variable BLOCKSIZE has a value starting with `HUMAN', then behaviour
is as for the -h option, unless overridden by -k or -m options. The variables
LANG, LC_ALL, LC_CTYPE and LC_MESSAGES have the usual meaning.
POSIX 1003.2
mount(8)
This page describes
df as found in the fileutils-4.0 package; other
versions may differ slightly.
