$re = '/^(?!\d*000)\d+$/m';
$str = '001234567502344001233400122300
0123456750023440012334012230
000123456750234400123340012230
001234567502344000123340012230
0012345675023440012334001223000
00123456750234400012334001223000
001002003004005006
000';
preg_match_all($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