I have had a similar problem and solved it using an array of hashes approach.

I would solve your issue using three array of hashes.

Write functions that get your two delimited files into an array of hashes. Something like:

# Function that gets passwordLogins from a text file
sub get_loginPasswords {
  my $filename = shift;
  my @loginPasswords;
  open F, "< $filename" or die "Cannot open logins file: $filename \n"
+;
  while (<F>) {
  chomp;            
  if ($_ =~ /\w+@\w+\.\w+,\w+/) {
    my ($login, $password);                 
    ( $login, $password ) = split( ',' );
    my $Login = {
                login         => $login,
                password     => $password
            };
    push @loginPasswords, $Login;        
  } else {
    die "Error in  login file format: $filename ";
  }
}
close F;
return \@loginPasswords;
}
[download]

Then do something like follows

for (%fileAArrayOfHashes)
  for (%fileBArrayOfHashes)
    if (file A column A matches file b column A) {
      add the columns you want to %hashC
      push (@fileCarrayOfHashes,\%hashC)
[download]

Sorry, the above syntax may be wrong even where it's not pseudocode, but the general idea should work.

Hope that helps!

thomas.