Meino Christian Cramer <Meino.Cramer / gmx.de> writes:
> 
>  I want to program a little tool with ruby, which find duplicate files
>  on filesystems.
> 

How about this ?

    $ find some_dir -type f -print0 | xargs -0 md5sum | sort | uniq -D -w32


Quite short, but not Ruby as you requested ;-)

/Johan Holmberg