HP-UX：bdf - report number of free disk blocks (Berkeley version)

The bdf command displays the amount of free disk space available either on the specified filesystem (/dev/dsk/c0d0s0, for example) or on the file system in which the specified file (such as $HOME), is contained. If no file system is specified, the free space on all of the normally mounted file systems is printed. The reported numbers are in kilobytes.