$re = '/facebook.*cpc/m';
$str = 'free.facebook.com
web.facebook.com
facebook/social/listing
facebook/referral/[facebook][marketplace][house][rent]
facebook/referral/[facebook][marketplace][townhouse][rent]
facebook/cpc/leadgen
facebook/cpc/[facebook][cpc][house][sale]
facebook/cpc/[facebook][cpc][condo][sale]
facebook/cpc/Aus + NZ, Men Over 50s, int Thailand/New Luxury Retirement Village in Southern Thailand
facebook/cpc/[facebook][cpc][townhouse][sale]
facebook/cpc/[facebook][cpc][condo][rent]
facebook/cpc/client->-developer->-leadgen
facebook/cpc/event/
facebook/cpc/[facebook][cpc][land][sale]';
preg_match_all($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