Hi,

As suggested by LanX please find the below code

use strict;
use warnings;
use Data::Dumper;

my %file1hash;

my $fin1="./dataset1.txt";
my $fin2="./dataset2.txt";

my ($fh1,$fh2);

open ($fh2, "<", "$fin2") or die $!;


%file1hash = map{ chomp; split / /; } <$fh2>;

print Dumper \%file1hash;

close $fh2;

open ($fh1, "<", "$fin1") or die $!;

while(<$fh1>){
        chomp;
        my ($id, $x1, $x2) = split / /;


        if (exists $file1hash{$id}) {
                printf ("%1s %5s %7s %10s\n", $id, $x1, $x2, $file1has
+h{$id});
        }

}

close $fh1;

exit;
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