$fh = @fopen("csv_file_name", "r");
if($fh) {
   if(flock($fh, lock_ex)) {
      while(!feof($fh)) {
         $line = fgets($fh);
         if(strstr($line, $target_email_address) !== false) {
            $data = split(",", $line); // $data *is* an array
         }
      }
      flock($fh, lock_un);
   }

   fclose($fh);
}