- var_dump: documentation ( source)
- preg_match: documentation ( source)
- parse_url: documentation ( source)
<?php
$string = "http://www.google.co.in/#hl=en&gs_rn=12&gs_ri=psy-ab&pq=bus%20online%20booking&cp=8&gs_id=20&xhr=t&q=redbus+offer+code&es_nrs=true&pf=p&sclient=psy-ab&oq=redbus+o&gs_l=&pbx=1&bav=on.2,or.r_qf.&bvm=bv.45960087,d.bmk&fp=e8cb228a72cb543b&biw=1280&bih=685";
$string = "http://www.google.co.in/#hl=en&gs_rn=12&gs_ri=psy-ab&pq=bus%20online%20booking&cp=8&gs_id=20&xhr=t&q=redbus+offer+code&es_nrs=true&pf=p&sclient=psy-ab&oq=redbus+o&gs_l=&pbx=1&bav=on.2,or.r_qf.&bvm=bv.45960087,d.bmk&fp=e8cb228a72cb543b&biw=1280&bih=685";
var_dump(parse_url($string));
$regex = "/q=(.*?)&/";
preg_match($regex, $string, $matches);
var_dump($matches);