v7 man page for du

DU(1)							      General Commands Manual							     DU(1)

NAME
       du  -  summarize disk usage

SYNOPSIS
       du [ -s ] [ -a ] [ name ... ]

DESCRIPTION
       Du  gives  the number of blocks contained in all files and (recursively) directories within each specified directory or file name.  If name
       is missing, `.'	is used.

       The optional argument -s causes only the grand total to be given.  The optional argument -a causes an entry to be generated for each  file.
       Absence of either causes an entry to be generated for each directory only.

       A file which has two links to it is only counted once.

BUGS
       Non-directories given as arguments (not under -a option) are not listed.
       If there are too many distinct linked files, du counts the excess files multiply.

																	     DU(1)