1)Linux
  gcc tree.c -o tree
  ./tree  /tmp
  ./tree  /etc

2)Windows
  Compile in PellesC (http://www.pellesc.de)

  then
    c:\> tree.exe  d:\\temp
  
3)Output
/etc
	/etc/firebird
		/etc/firebird/2.5
			firebird.conf
	/etc/dictionaries-common
		ispell-default
		words
	/etc/console-setup
		compose.GEORGIAN-PS.inc
		vtrgb
		compose.ISO-8859-9.inc
		compose.CP1256.inc
		Uni2-Fixed16.psf.gz
		compose.ISO-8859-5.inc
		compose.ISIRI-3342.inc
        ...