Question

I’ve found a few keyword extractors for query strings, but they all seem to be outdated (use deprecated code or simply don’t work).

Does anyone know of a php query string extractor. Or how would I build a function that takes a “host” like “amazon.com” and the names of multiple query parameters and returns the values of those parameters?

For instance, http://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Daps&field-keywords=a+tale+of+two+cities&x=0&y=0

If I provided “amazon.com” and “field-keywords” how can I get the array: ['a','tale','of','two','cities'] ?

Thanks in advance!!

Clarification

Jose’s answer covers my example for Amazon but doesn’t seem to work for any other URL:

http://www.bing.com/search?q=Christmas+Around+The+World&form=QBLH&qs=PN&sk=HS1PN4&pq=&sp=6&sc=8-0

http://search.yahoo.com/search;_ylt=AnQN0c997QR5SIYcYt.h2YCbvZx4?p=golf&toggle=1&cop=mss&ei=UTF-8&fr=yfp-t-701

Answer 1

You (I) could write one.

function getValueFromDomain($urls, $domain, $key) {
    foreach ($urls as $url) {
        if (preg_match('/https?:\/\/[^\/]*?' . preg_quote($domain) . '\//', $url)) {
            parse_str(substr($url, strpos($url, '?') + 1), $output);
            if (isset($output[$key])) {
                $array = explode(' ', $output[$key]);
                return $array;
            }
        }
    }
    return array();
}

Just a tad of code stolen from @Jose’s answer 🙂

Update: tested, didn’t work, fixed, works.

Update 2: didn’t work after all, tested, fixed, works.

Update 3: added support for HTTPS