my $rcfile = 'testrc'; # sets TESTEX to "test!"

if(open(CHILD_TO_READ, ". $rcfile; env | sort |"))
  {
    while (<CHILD_TO_READ>)
      {
        my ($key, $val) = split '=';
        $ENV{$key} = $val;
      };
  }

print $ENV{TESTEX};