[NAME]df \- report filesystem disk space usage[DESCRIPTION]This manual pagedocuments the GNU version of.BR df ..B dfdisplays the amount of disk space available on the filesystemcontaining each file name argument.  If no file name is given, thespace available on all currently mounted filesystems is shown.  Diskspace is shown in 1K blocks by default, unless the environmentvariable POSIXLY_CORRECT is set, in which case 512-byte blocks areused..PPIf an argument is the absolute file name of a disk device node containing amounted filesystem,.B dfshows the space available on that filesystem rather than on thefilesystem containing the device node (which is always the rootfilesystem).  This version of.B dfcannot show the space available on unmounted filesystems, because onmost kinds of systems doing so requires very nonportable intimateknowledge of filesystem structures..SH OPTIONS