$re = '/^([0-8]\d{4}|97[0-6]\d{2}|98[06-9]\d{2}|9[0-69]\d{3})$/m';
$str = '01001
11010
23034
34567
2343
45678
56786
67896
7856
8990
89999
999999
9741
9751
9761
9771
9781
9791
9811
9821
9831
9841
9851
9861
98l1
1000
29098
78999
98899
98900';
preg_match_all($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