Re^5: Compare three columns of one file with three columns of another file in perl

Hi Thanks.Below is the code i tried but it does not print anything to the STDOUT.

    #!usr/bin/perl
      use strict;
      use warnings;

      my ($infile1,$infile2) = @ARGV;
      open (IFILE1, "<", $infile1) || die "Cannot open        $infile1
+:$!\n";
      open (IFILE2, "<", $infile2) || die "Cannot open $infile2:$!\n";

     my @array1;
     my %hash1;
     my $str;
     while (<IFILE1>) {
         @array1 = split (" ", $_);
         $str = $array1[0]."\t".$array1[1]."\t".$array1[2];
     $hash1{$str} = 1;
    }
    close IFILE1;
     my @array2;
     my $string;
    while (<IFILE2>) {
        @array2 = split (" ", $_);
        $string =  $array2[0]."\t".$array2[3]."\t".$array2[4];
        #print "$string\n";
        if (exists($hash1{$string})) {
          print "$string\n";
        }
    }
    close IFILE2;
[download]

Comment on Re^5: Compare three columns of one file with three columns of another file in perl Download Code

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Re^6: Compare three columns of one file with three columns of another file in perl by anonym (Acolyte) on May 26, 2015 at 05:04 UTC
Hey thanks.The code i sent works with the other pair of input files. I guess there is no line common between file1.txt and file2.txt that is why it does not print anything.	[reply]
Re^7: Compare three columns of one file with three columns of another file in perl by aaron_baugher (Curate) on May 26, 2015 at 17:19 UTC
You're welcome, you did a good job of turning my pseudo-code into working code! One suggestion: don't create variables outside a loop if they're only used within the loop. So your `@array1` can be instantiated inside your first loop, like this: `my @array1 = split (" ", $_);` [download] Same thing with `@array2, $str, and $string`. The way you're doing it will work, but it may introduce bugs in more complicated code, because those variables will continue to exist after those loops are finished, and could conflict with other uses elsewhere. It's best to keep variables inside as small a context as possible, so only create them outside a loop if you need them to continue to exist after the loop is finished. Aaron B. Available for small or large Perl jobs and *nix system administration; see my home node.	[reply] [d/l] [select]
Re^8: Compare three columns of one file with three columns of another file in perl by anonym (Acolyte) on May 27, 2015 at 16:28 UTC
Thanks Aaron for your suggestions and help. Thanks so much.	[reply]