NAME

df — display free disk space

SYNOPSIS

DESCRIPTION

The 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 -l and -t options, below).

The options are as follows:

-h

"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 -P option.

-i

Include statistics on the number of free inodes. This option is incompatible with the -P option.

-k

By default, all sizes are reported in 512-byte block counts. The -k option causes the numbers to be reported in kilobyte counts.

-l

Display statistics only about mounted file systems with the MNT_LOCAL flag 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.

-n

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, df will not request new statistics from the file systems, but will respond with the possibly stale statistics that were previously obtained.

-P

Print out information in a stricter format designed to be parsed by portable scripts. The BLOCKSIZE environment variable is ignored when this option is specified.

-t type

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 exclusive options -h and -k. Where more than one of these options is specified, the last option given overrides the others.

ENVIRONMENT

BLOCKSIZE

Display block counts in units of size BLOCKSIZE. Ignored if any of the -h, -k or -P options are specified.

EXIT STATUS

The df utility exits 0 on success, and >0 if an error occurs.

EXAMPLES

Output, in a strict format suitable for portable scripts, disk space statistics for the /usr file system using kilobyte block sizes:

SEE ALSO

quota(1), getfsstat(2), statfs(2), getmntinfo(3), fstab(5), mount(8), quot(8)

STANDARDS

The df utility is compliant with the IEEE Std 1003.1-2008 (“POSIX.1”) specification.

The flags [-hiln], as well as the BLOCKSIZE environment variable, are extensions to that specification.

This implementation provides the traditional BSD -t behaviour, which differs from the X/Open System Interfaces option specification.

HISTORY

A df utility appeared in Version 1 AT&T UNIX.