dirname /x/y/z/
removing extension from file
$ basename /this/is/a/file.txt .txt
List subdirectores sorted by size
du -k | sort -n
List file sorted by size
ls -l | sort +4n
only in linux :
file size in K,M : ls -lh
files sorted by size : ls -lS
symbols along with file type
ls -F
List just the directory
ls -ld dirname
