display free disk space
df utility displays statistics about
the amount of free disk space on the specified
file_system or on the file system of which
file is a part. By default, values are displayed as
512-byte block counts. If no operands are specified, statistics for all
mounted file systems are displayed (subject to the
The options are as follows:
- "Human-readable" output. Use unit suffixes: Byte, Kilobyte,
Megabyte, Gigabyte, Terabyte, Petabyte, Exabyte in order to reduce the
number of digits to four or less. This option is incompatible with the
- Include statistics on the number of free inodes. This option is
incompatible with the
- By default, all sizes are reported in 512-byte block counts. The
-koption causes the numbers to be reported in kilobyte counts.
- Display statistics only about mounted file systems with the
MNT_LOCALflag set. If a non-local file system is given as an argument, a warning is issued and no information is given on that file system.
- Print out the previously obtained statistics from the file systems. This
option should be used if it is possible that one or more file systems are
in a state such that they will not be able to provide statistics without a
long delay. When this option is specified,
dfwill not request new statistics from the file systems, but will respond with the possibly stale statistics that were previously obtained.
- Print out information in a stricter format designed to be parsed by portable scripts.
- Indicate the actions should only be taken on file systems of the specified type. More than one type may be specified in a comma-separated list. The list of file system types can be prefixed with “no” to specify the file system types for which action should not be taken. If a file system is given on the command line that is not of the specified type, a warning is issued and no information is given on that file system.
It is not an error to specify more than one of the mutually
Where more than one of these options is specified, the last option given
overrides the others.
- If the environment variable
BLOCKSIZEis set, and the
-koptions are not specified, the block counts will be displayed in units of that size block.
df utility exits 0 on success,
and >0 if an error occurs.
Output, in a strict format suitable for portable scripts, disk space statistics for the /usr file system using kilobyte block sizes:
$ df -kP /usr
quota(1), getfsstat(2), statfs(2), getmntinfo(3), fstab(5), mount(8), quot(8)
df utility is compliant with the
IEEE Std 1003.1-2008 (“POSIX.1”)
The flags [
-hiln], as well as the
BLOCKSIZE environment variable, are extensions to
This implementation provides the traditional
-t behaviour, which
differs from the X/Open System Interfaces option specification.
df utility appeared in
Version 3 AT&T UNIX.