du(1)
NAME
du − summarize disk usage
SYNTAX
du [ −s ] [ −a ] [ name ... ]
DESCRIPTION
The du command gives the number of kilobytes contained in all files and, recursively, directories within each specified directory or file name. If name is missing, ‘.’ is used.
The argument −s causes only the grand total to be given. The 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.