$re = '/(?=.*[a-fA-F]+)(?=.*[0-9]+)[a-zA-Z0-9]{10}/m';
$str = '111111111a
7777dddddd
9999999999
88888888A
88888888AAA
88888A
AAAAAAAAA
asdfasddad
bnmmnbamnb
8adfl9542a
ammmmmmmmm
mammmmmmmm
0mmmmmmmmm
m0ammmmmmm
on5pn0nmon
qqqq55511s
11111a1111
11111111111';
preg_match_all($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