in reply to Re: Comparing lines of multiple files
in thread Comparing lines of multiple files

After much head-scratching (I originally wrote a "what are you asking here?" response, too), I decided that what the OP meant was:

If an ID occurs in only one file, print the corresponding line.

If an ID occurs in multiple files, and all the corresponding lines have the exact same text, print the line.

This does correspond to the sample output. (I'm still puzzled by 'unless one of the IDS was blank.')

  • Comment on Re^2: Comparing lines of multiple files

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Re^3: Comparing lines of multiple files
by oomwrtu (Novice) on Oct 09, 2005 at 23:06 UTC
    Thank you to everyone for your patience. I stumbled on this site and was so excited about the possibility of solving this problem that I didn't take as much time rereading what I posted (I know that's not a good thing). One thing I would like to clear up is that I am using this on a webpage, so many of the errors that you guys might be seeing aren't shown (unless I check the logs, which I should do). graff's code and Zed_Lopez's rewording had it almost entirely correct for two files. I actually have 3 files that I would like to combine, but I reduced it to 2 when I was working on it to try and simplify it.

    -:-:- I deleted the rest of what I said because GrandFather posted code that I was able to use and adapt for three files. I am pretty sure it works as I want it to. It isn't nearly as efficient as graff's code, but it works. :D Again, thank you to everyone for your help. -:-:-
      Here's a first pass at cleaning up the main loop of your code. It's not tested, so don't trust it, but it ought to do exactly the same thing, faster.

      The code is easier to read this way. So easy that I can see a BUG! (I left it in with a comment).

      The program could be made even clearer and further optimized, but this is a start. For example you can replace all the print DAT $c; with $all .= $c; and, wait till the end to open the file for append, print DAT $all;, and close.

      By the way, if you can, you should test this in a standalone program on your computer, not just on the web.

      # 1. Only open/close the file once to append, instead of $maxid times. # 2. Use temporary values. # 3. Delete stuff you don't need immediately, not next time around loo +p. # 4. In this case, ($c) is same as (defined $c) (cosmetic). open(DAT,">>data/parsed-all.txt"); for(my $i = 1; $i <= $maxid; $i++) { my $currid = changeID($i); my ($c1,$c2,$c3) = ($compare1{$currid}, $compare2{$currid}, $compare +3{$currid}); delete $compare1{$currid}, $compare2{$currid}, $compare3{$currid}; next if( $c1 && $c2 && $c3 && $c1 ne $c2 && $c1 ne $c3 && $c2 ne $c3 + ); if( $c1 && !$c2 && !$c2 ) { print DAT $c1; next; } if( $c2 && !$c1 && !$c3 ) { print DAT $c2; next; } if( $c3 && !$c1 && !$c2 ) { print DAT $c2; # <-- BUG HERE! next; } if( $c1 && $c2 ) { if( $c1 eq $c2 ) { print DAT $c1; next; } } if( $c1 && $c3 ) { if( $c1 eq $c3 ) { print DAT $c1; next; } } if( $c2 && $c3 ) { if( $c2 eq $c3 ) { print DAT $c2; next; } } } close(DAT);