1'\" Copyright (C) 1998-1999, 2004, 2009-2010 Free Software Foundation, Inc. 2'\" 3'\" This is free software. You may redistribute copies of it under the terms 4'\" of the GNU General Public License <http://www.gnu.org/licenses/gpl.html>. 5'\" There is NO WARRANTY, to the extent permitted by law. 6[NAME] 7df \- report file system disk space usage 8[DESCRIPTION] 9This manual page 10documents the GNU version of 11.BR df . 12.B df 13displays the amount of disk space available on the file system 14containing each file name argument. If no file name is given, the 15space available on all currently mounted file systems is shown. Disk 16space is shown in 1K blocks by default, unless the environment 17variable POSIXLY_CORRECT is set, in which case 512-byte blocks are 18used. 19.PP 20If an argument is the absolute file name of a disk device node containing a 21mounted file system, 22.B df 23shows the space available on that file system rather than on the 24file system containing the device node (which is always the root 25file system). This version of 26.B df 27cannot show the space available on unmounted file systems, because on 28most kinds of systems doing so requires very nonportable intimate 29knowledge of file system structures. 30.SH OPTIONS 31