Re^2: compare two files by column and return second (matching) column

[ejbiers]

This is perfect! Thanks! However, is there a way to print the results into an output file?

[Kenosis]

You're most welcome, ejbiers! Yes, the script below includes printing the results to a file:

use Modern::Perl;

open my $fhA, '<', 'FileA.txt' or die $!;
my %hash = map { /(.+)\t(.+)/; $1 => $2 } grep /\S/, <$fhA>;
close $fhA;

open my $fhB, '<', 'FileB.txt' or die $!;
my @output = map { chomp; $hash{$_} } grep /\S/, <$fhB>;
close $fhB;

open my $fhO, '>', 'Output.txt' or die $!;
say $fhO $_ for @output;
close $fhO;