$re = '/^([-+*\/\(]?[\(]?([1-9]{1}[0-9]+)[.]?[0-9]+[\)]?[\)]?)([-+*\/\(]?[\(]?[\(]?([1-9]{1})([0-9]+)?[.]?([0-9]+)?[\)]?[\)]?)?([-+*\/\(]?[\(]?[\(]?([1-9]{1})([0-9]+)?[.]?([0-9]+)?[\)]?[\)]?)?([-+*\/\(]?[\(]?[\(]?([1-9]{1})([0-9]+)?[.]?([0-9]+)?[\)]?[\)]?)?([-+*\/\(]?[\(]?[\(]?([1-9]{1})([0-9]+)?[.]?([0-9]+)?[\)]?[\)]?)?([-+*\/\(]?[\(]?[\(]?([1-9]{1})([0-9]+)?[.]?([0-9]+)?[\)]?[\)]?)?$/mx';
$str = '+690.91+1-2-1-3-4
+690.91+1-2-1-3-4-1
+690.91+1-2-1';
preg_match_all($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