Command:   du - print disk usage
Syntax:    du [-as] [-l n] dir ...
Flags:     -a  Give usage for all files
           -l  List up to n levels of subdirectories
           -s  Summary only
Examples:  du dir                   # List disk space used by  files  in
                                      dir
           du -s dir1 dir2          # Give summaries only

     Du examines one or more directories and prints the amount of  space
occupied by the files in those directories and their subdirectories.