$re = '/^\d+[.,]?\d*$|^[.,]\d*$/m';
$str = '
111.
11.
11,
1111,
.123
,.123
11.,
,123.
11.,
,.
,
.1
asdf
,12312
.12,
1231.
1231,.
';
preg_match_all($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