Another approach would be to use a hash for first file and use exists operator to check for the existance of each key in second. Example : 
#!/usr/bin/perl -w

use strict;

my %fets;
print "\n\n";

open IHF, "<File1" || die "Could not open  File1".$!;
while( <IHF> ) {
   my ($k, $v) = split;
   $fets{$k} = $v if defined ($k) and defined ($v);
}
close IHF ;

open JHF, "<File2" || die "Could not open  File2".$!;
while(<JHF>) {
   my ($key, $val) = split;
   print  $key."  ".$fets{$key}."  ".$val."\n" if exists $fets{$key} ;
}
close JHF ;

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Thanks..

In reply to Re: Perl Code Runs Extremely Slow by Mandrake
in thread Perl Code Runs Extremely Slow by garbage777

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