32v 1m du
DU(1) UNIX Programmer's Manual DU(1)
du - summarize disk usage
du [ -s ] [ -a ] [ name ... ]
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.
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.