in reply to Command Line Hash to print things in common between two files

Perhaps something like this:
Detect common lines between two files, one liner from shell
  • Comment on Re: Command Line Hash to print things in common between two files

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Re^2: Command Line Hash to print things in common between two files
by ZWcarp (Beadle) on Jan 10, 2012 at 20:41 UTC
    This is on the right track but I need to be able to tell it which columns to check because the whole lines are never going to be in common?
      You will get more useful answers if you show a few lines of the file(s) to be analysed.

      CountZero

      A program should be light and agile, its subroutines connected like a string of pearls. The spirit and intent of the program should be retained throughout. There should be neither too little or too much, neither needless loops nor useless variables, neither lack of structure nor overwhelming rigidity." - The Tao of Programming, 4.1 - Geoffrey James

      Despite your requirement that this be "on the command line," you might solve this yourself by understanding and then extending the example offered or an answer which can be found in one of the many other SOPW's asking about essentially the same chore.

      And, yes, it's more likely the latter, since you want to test the content of a specific column (you didn't say which one) in each line in file against the content of a specific column in any line in a second file...

      ... or is that not what you meant? The phrase "where the column from file 1 matches somewhere in file 2" makes me wonder if you're looking for any column in a given (same line number) line in file 2 that matches the content of the specified column in a particular line in file 1. Your reply to the first answer would appear to rule that out were it not for the terminal punctuation -- a question mark!

      The first step to solving your problem is probably re-stating it to yourself, in a clear, precise and unambiguous manner.

      Update: Upon posting this reply, discovered that ZWcarp had made major, un-acknowledged revisions to the OP. meh!
      Added: (and his code doesn't compile under strict. At line 15, Global symbol "@file2" requires explicit package name

      Re-updated. (Yech): OP's first update (prior to adding the reference to "a gene identifier number or a CG number. These are always numbers and letter delimited somehow.") left the requirement ambiguous (at least to me) so I prepped this, seeking clarification. Clearly, it's not characteristic of the new spec, but, FTR:

      File 1 File2 Col 1 Col2 Col3 Col4 Col 1 Col2 Col3 Col4 1 2 3 4 4 3 2 1 4 3 2 1 a b c d 10 11 12 13 12 11 13 10 a1 b c d a4 b4 c d4 Line 1: no matches Line 2: # F1, L2 matches F2, L1 Line 3: # F1, L3,Col2 matches F2, L3, Col2 Line 4: # F1, L4,Cols 2, 3 & 4 match F2, L2, Cols 2, 3 & 4 # and also matches contents of F2, L4, Col3 # Do both satisfy your criteria?

      Where "F1" (in the data sample) means File1, "L2" means Line 2 and "Col" and "Cols" are -- I hope -- self explanatory.

        I apologize my question is confusing and that I haven't followed proper update protocol. Please do not interpret my mistakes as a lack of care to post things the proper way on this forum. I changed around the question multiple times in order to attempt to make it more clear, and to try and address the previous answers. The script I posted doesn't compile because I edited all the variable names to try to make them generic and thus clear, and I left one unchanged by mistake.

        All I want to do is learn how to use perl to accomplish the same thing done with the unix join command in a bash environment because it would make my life much easier if I didn't have to write a script every time I need to analyze a particular unison between two files. Join works great but I would like to have finer control than it allows.