(fileutils.info)du invocation

`du': Estimate file space usage
===============================

   `du' reports the amount of disk space used by the specified files
and for each subdirectory (of directory arguments).  Synopsis:

     du [OPTION]... [FILE]...

   With no arguments, `du' reports the disk space for the current
directory.  The output is in 1024-byte units by default, unless the
environment variable `POSIXLY_CORRECT' is set, in which case 512-byte
blocks are used (unless `-k' is specified).

   The program accepts the following options.  Also see Note: Common
options.

`-a'
`--all'
     Show counts for all files, not just directories.

`-b'
`--bytes'
     Print sizes in bytes, instead of kilobytes.

`-c'
`--total'
     Print a grand total of all arguments after all arguments have been
     processed.  This can be used to find out the total disk usage of a
     given set of files or directories.

`-D'
`--dereference-args'
     Dereference symbolic links that are command line arguments.  Does
     not affect other symbolic links.  This is helpful for finding out
     the disk usage of directories, such as `/usr/tmp', which are often
     symbolic links.

`-h'
`--human-readable'
     Append a size letter, such as `M' for megabytes, to each size.

`-k'
`--kilobytes'
     Print sizes in kilobytes.  This overrides the environment variable
     `POSIXLY_CORRECT'.

`-l'
`--count-links'
     Count the size of all files, even if they have appeared already
     (as a hard link).

`-L'
`--dereference'
     Dereference symbolic links (show the disk space used by the file
     or directory that the link points to instead of the space used by
     the link).

`-m'
`--megabytes'
     Print sizes in megabyte (that 1,048,576 bytes) blocks.

`-s'
`--summarize'
     Display only a total for each argument.

`-S'
`--separate-dirs'
     Report the size of each directory separately, not including the
     sizes of subdirectories.

`-x'
`--one-file-system'
     Skip directories that are on different filesystems from the one
     that the argument being processed is on.

   On BSD systems, `du' reports sizes that are half the correct values
for files that are NFS-mounted from HP-UX systems.  On HP-UX systems,
it reports sizes that are twice the correct values for files that are
NFS-mounted from BSD systems.  This is due to a flaw in HP-UX; it also
affects the HP-UX `du' program.