From: Meino Christian Cramer <Meino.Cramer@...>
Date: 2003-09-06T16:59:21+09:00
Subject: Hash-ish and Arrays and Duplicates

Hi,

 How would you do this the ruby-way ?

 I want to program a little tool with ruby, which find duplicate files
 on filesystems.

 Currently I have a hash, which key is the fully qualified
 pathname/file and its value is the md5sum (by the way: Is there a
 md5sum-generator inside Ruby ?) of that file.

 It is possible, that a certain md5sum is stored multiple times as
 hash value.

 To find, whether there are duplicated files at all I did (fphash is
 the hash mentioned above):

 ifphash=fphash.invert
 if( ifphash.length != fphash.length )
	 p "Duplicates indicated!"
 end

 This is quite simple, a little brute force and fast.

 But now the tricky part, for which I do not have a solution beside
 the step by step method, which works with nearly every programming
 language. 

 WHICH files are duplicated ?

 The "invert" deletes the information except of one file, since all
 now duplicated keys are deleted.

 fparr=fphash.values
 fparr.uniq!

 did quite the same thing.

 Methods like has_value? and has_key? only returns a boolean value but
 not the corresponding item(s).

 Is there a method or ruby-"trick" to solve the problem ?
  
 Thank you very much in advance for any help and/or hint ! :)

 Have a nice weekend!
 Meino Cramer


	   Dont worry, be ruby!

	   I like rubymental programming !