Difference of two list files.

subr01 has asked for the wisdom of the Perl Monks concerning the following question:

If I have two list files A and B which has a number of lines. I want C to have all that in B that is not in A. And how shall I store the result? In an array?

A: 1,3,4
   2,3
   2.4/2

B: 1,3,4
   2.4/2
   5,6
[download]

Then C should contain


C: 5,6
[download]

Comment on Difference of two list files. Select or Download Code

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Re: Difference of two list files. by Discipulus (Canon) on Jun 01, 2015 at 10:42 UTC
Hello subr01 you can find How can I find the union/difference/intersection of two arrays? an interesting read. L* There are no rules, there are no thumbs.. Reinvent the wheel, then learn The Wheel; may be one day you reinvent one of THE WHEELS.	[reply] [d/l]
Re^2: Difference of two list files. by subr01 (Novice) on Jun 01, 2015 at 11:35 UTC
Thank you monk. Got it.	[reply]
Re: Difference of two list files. by Corion (Patriarch) on Jun 01, 2015 at 10:43 UTC
This is a FAQ. See perlfaq4 about How do I compute the difference of two arrays? Also see List::Compare.	[reply]
Re: Difference of two list files. by Anonymous Monk on Jun 01, 2015 at 20:07 UTC
Can be accomplished with the unix comm utility: $ comm -13 fileA fileB > fileC (A requirement is that the lists be sorted.)	[reply]