$re = '/amazon\.com/dp/(\w{10})/';
$str = 'u\'http://www.amazon.com/dp/B003T0G9GM/ref=wl_it_dp_v_nS_ttl/177-5611794-0982247?_encoding=UTF8&colid=SBGZJRGMR8TA&coliid=I205LCXDIRSLL3\'';
preg_match($re, $str, $matches, PREG_OFFSET_CAPTURE, 0);
// Print the entire match result
var_dump($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