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. 

RESTRICTIONS

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.