$re = '/https:\/\/us[0-9]+\.zopim\.com\/s\/w\/spm\/[0-9a-zA-Z]+\/c\/[0-9]+/m';
$str = 'https://us24.zopim.com/s/w/spm/2mwsw010ht6a3jdk/c/1507617726879
https://us34.zopim.com/s/w/spm/rtyortahxceczngb/c/1507618624653
https://us24.zopim.com/s/w/spm/2mwsw010ht6a3jdk/c/1507617726879';
preg_match_all($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