$re = '/\b([^0]....)\b/m';
$str = '21678 - 00000|00000|21678|64826
64826 - 00000|00000|21678|64826
45245 - 45106|45245|00000|00000
45106 - 45106|45245|00000|00000';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php