#!/usr/bin/perl

# http://perlmonks.org/?node_id=1133207

use strict;
$| = 1;

my $file1 = <<END;
name1 ABCD
name2 BCD
name3 ASCDA
name4 AAAAA
END

my $file2 = <<END;
name1 0.2
name5 0.3
name4 0.0002
name7 0.222
END

open my $one, '<', \$file1 or die "$! opening file1";
my %hash1 = split ' ', do{ local $/; <$one> };
close $one;

#use YAML; print Dump \%hash1;

open my $two, '<', \$file2 or die "$! opengin file2";
while(<$two>)
  {
  my ($key) = split;
  exists $hash1{$key} and print "$key $hash1{$key}\n";
  }
close $two;