DF
NAME
df - report filesystem disk space usage
SYNOPSIS
df [options] [file...]
POSIX options:
[-kP]
GNU options (shortest form):
[-ahikmPv]
[-t fstype]
[-x fstype]
[--print-type]
[--no-sync]
[--sync]
[--help] [--version] [--]
DESCRIPTION
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) as listed in /configure/mtab.
Otherwise,
df
reports on the filesystem containing each argument
file.
POSIX DETAILS
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.
GNU DETAILS
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.
POSIX OPTIONS
- -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).
GNU OPTIONS
- -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.
- -h, --human-readable
-
Append a size letter such as
M
for megabytes to each size.
- -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.
- -m, --megabytes
-
Print sizes in megabyte (that's 1,048,576 bytes) blocks.
- --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the results may be slightly out of date.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.
## the default behavior appears to be to perform a sync in cLIeNUX.
- -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.
GNU STANDARD OPTIONS
- --help
-
Print a usage message on standard output and exit successfully.
- --version
-
Print version information on standard output, then exit successfully.
- --
-
Terminate option list.
ENVIRONMENT
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.
CONFORMING TO
POSIX 1003.2
SEE ALSO
mount(8)
NOTES
This page describes
df
as found in the fileutils-3.16 package;
other versions may differ slightly. Mail corrections and additions to
aeb@cwi.nl and aw@mail1.bet1.puv.fi and ragnar@lightside.ddns.org .
Report bugs in the program to fileutils-bugs@gnu.ai.mit.edu.