I need a little jumpstart here - kind of stuck at the moment. Maybe there are a couple modules you can suggest? I'm familiar with List::Compare and Array::Compare.

Problem:
File 1 format: 9-digit-number year string
File 2 format: 9-digit-number year

So, file 1 may look like:

123456789 1900 foobar
123456789 1901 fooba
123456788 2000 foob
(notice the possible repetition of the 9-digit-number) file 2 looks similar, minus the string.

What I need is to compare the 9 digit number+year combination between the two files by running through file 1 and comparing against file 2. If file 2 does not have a match for the line in file 1, spit out the line grabbed from file 1 (INCLUDING the string) into a separate file.

Maybe I'm making this too hard for myself, but so far I figure something like:

open all files
grab all lines from file 1 - split each line into 3 strings( $number, 
+$year, $string)
concatenate $number.$year into one $searchvalue
make hash with keys of $searchvalue and values of $string 
populate array1 with these $searchvalues
grab all lines from file 2 into array2
compare array1 to array2
where value from array1 doesn't find a match in file2, print hash valu
+e with the key of $searchvalue to file results

[download]
this close? any tips, suggestions? Thanks!

In reply to pseudocode needed - comparing multiple columns of two files by Anonymous Monk

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