.\"-
.\" Copyright (c) 1989, 1990, 1993
.\"	The Regents of the University of California.  All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\" 4. Neither the name of the University nor the names of its contributors
.\"    may be used to endorse or promote products derived from this software
.\"    without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\"     @(#)df.1	8.3 (Berkeley) 5/8/95
.\" $FreeBSD$
.\"
.Dd March 3, 2012
.Dt DF 1
.Os
.Sh NAME
.Nm df
.Nd display free disk space
.Sh SYNOPSIS
.Nm
.Op Fl b | g | H | h | k | m | P
.Op Fl acilnT
.Op Fl t Ar type
.Op Ar file | filesystem ...
.Sh DESCRIPTION
The
.Nm
utility
displays statistics about the amount of free disk space on the specified
.Ar file system
or on the file system of which
.Ar file
is a part.
Values are displayed in 512-byte per block counts.
If neither a file or a file system operand is specified,
statistics for all mounted file systems are displayed
(subject to the
.Fl t
option below).
.Pp
The following options are available:
.Bl -tag -width indent
.It Fl a
Show all mount points, including those that were mounted with the
.Dv MNT_IGNORE
flag.
This is implied for file systems specified on the command line.
.It Fl b
Use 512-byte blocks rather than the default.
Note that
this overrides the
.Ev BLOCKSIZE
specification from the environment.
.It Fl c
Display a grand total.
.It Fl g
Use 1073741824-byte (1-Gbyte) blocks rather than the default.
Note that
this overrides the
.Ev BLOCKSIZE
specification from the environment.
.It Fl H
.Dq Human-readable
output.
Use unit suffixes: Byte, Kilobyte, Megabyte,
Gigabyte, Terabyte and Petabyte in order to reduce the number of
digits to four or fewer using base 10 for sizes.
.It Fl h
.Dq Human-readable
output.
Use unit suffixes: Byte, Kilobyte, Megabyte,
Gigabyte, Terabyte and Petabyte in order to reduce the number of
digits to four or fewer using base 2 for sizes.
Inodes statistics, if enabled with
.Fl i ,
are always printed in base 10.
.It Fl i
Include statistics on the number of free inodes.
.It Fl k
Use 1024-byte (1-Kbyte) blocks rather than the default.
Note that
this overrides the
.Ev BLOCKSIZE
specification from the environment.
.It Fl l
Only display information about locally-mounted file systems.
.It Fl m
Use 1048576-byte (1-Mbyte) blocks rather than the default.
Note that
this overrides the
.Ev BLOCKSIZE
specification from the environment.
.It Fl 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,
.Nm
will not request new statistics from the file systems, but will respond
with the possibly stale statistics that were previously obtained.
.It Fl P
Use POSIX compliant output of 512-byte blocks rather than the default.
Note that this overrides the
.Ev BLOCKSIZE
specification from the environment.
.It Fl t
Only print out statistics for file systems of the specified types.
More than one type may be specified in a comma separated list.
The list of file system types can be prefixed with
.Dq no
to specify the file system types for which action should
.Em not
be taken.
For example, the
.Nm
command:
.Bd -literal -offset indent
df -t nonfs,nullfs
.Ed
.Pp
lists all file systems except those of type
.Tn NFS
and
.Tn NULLFS .
The
.Xr lsvfs 1
command can be used to find out the types of file systems
that are available on the system.
.It Fl T
Include file system type.
.El
.Sh ENVIRONMENT
.Bl -tag -width BLOCKSIZE
.It Ev BLOCKSIZE
If the environment variable
.Ev BLOCKSIZE
is set, the block counts will be displayed in units of that size block.
.El
.Sh SEE ALSO
.Xr lsvfs 1 ,
.Xr pstat 1 ,
.Xr quota 1 ,
.Xr swapinfo 1 ,
.Xr fstatfs 2 ,
.Xr getfsstat 2 ,
.Xr statfs 2 ,
.Xr getmntinfo 3 ,
.Xr fstab 5 ,
.Xr mount 8 ,
.Xr quot 8
.Sh HISTORY
A
.Nm
command appeared in
.At v1 .
.Sh BUGS
The
.Fl n
flag is ignored if a file or file system is specified.
Also, if a mount
point is not accessible by the user, it is possible that the file system
information could be stale.