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.\" Copyright (c) 2003 Gunnar Ritter
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.\" Sccsid @(#)df.1	1.23 (gritter) 2/5/03
.TH DF 1B "12/9/04" "Heirloom Toolchest" "BSD System Compatibility
.SH NAME
df \- (BSD) disk free
.SH SYNOPSIS
\fB/usr/ucb/df\fR [\fB\-aihkP\fR] [\fB\-M\fI mtab\fR]
[\fB\-t\fI fstype\fR | \fIfile\fR ...]
.SH DESCRIPTION
Df prints file system statistics.
A file system is selected
by a file it contains,
or by its device file,
as specified by the
.I file
argument.
If no
.I file
argument is given,
statistics are printed for all mounted file systems.
.PP
The
.B df
command accepts the following options:
.TP
.B \-a
Print statistics for all mounted file systems.
Normally, file systems with zero block count are omitted.
.TP
.B \-i
Print i-node statistics.
.TP
.BI \-t \ fstype
Restrict output to filesystems of type
.I fstype.
.PP
The following options have been introduced by POSIX.2:
.TP
.B \-P
Select the portable 
.SM (POSIX)
output format.
Changes the default size unit
to a block consisting of 512 bytes.
.TP
.B \-k
If combined with the \-P option,
the size unit is changed from blocks to kbytes.
.PP
The following options are extensions:
.TP
.B \-h
Prints the sizes in human-readable powers of 1024,
i.\|e. `K' for kilobyte,
`M' for megabyte,
`G' for gigabyte,
`T' for terabyte,
`P' for petabyte,
and `E' for exabyte.
.TP
.BI \-M \ mtab
Use the specified
.I mtab
file to get a list of mounted filesystems.
.SH FILES
.TP
.B /etc/mtab
default mount table
.SH "SEE ALSO"
find(1),
statvfs(2),
mtab(5),
mount(8)
.SH NOTES
.PP
This
.I df
implementation cannot handle unmounted file systems.
.PP
Some advanced file system designs allocate i-nodes dynamically.
.I Df
then tries to estimate free and total counts of available files.
This is currently done for the
.I reiserfs
file system.