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

Excellent suggestions have been given. Here's another option:

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 $!;
say for map { chomp; $hash{$_} } grep /\S/, <$fhB>;
close $fhB;
[download]

Output:

zzzzz
bbbbb
xxxxx
[download]

The first map uses a regex to grab the key/value pairs from FileA for placement into %hash. The second map uses the single entry from FileB to show that entry's associated value from FileA. Since there were blank lines in the files (from your data set), grep /\S/ was used to filter those.

Hope this helps!

Comment on Re: compare two files by column and return second (matching) column Select or Download Code

Replies are listed 'Best First'.
Re^2: compare two files by column and return second (matching) column by ejbiers (Initiate) on Aug 07, 2012 at 13:45 UTC
This is perfect! Thanks! However, is there a way to print the results into an output file?	[reply]
Re^3: compare two files by column and return second (matching) column by Kenosis (Priest) on Aug 07, 2012 at 15:28 UTC
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;` [download]	[reply] [d/l]