PHP, remove string using "pattern"

I have the following url which will always have a color variable attached:

http://www.example.com/?new=yes&color=red&shape=square

How would I, using PHP, remove everything at the end; starting at &color, so I开发者_如何学运维 am left with the following:

http://www.example.com/?new=yes

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The literal answer to your question is:

$url = substr($url, 0, strpos($url, '&color='));

However, this is good only for the specific case -- it would probably be a good idea to do something a little more robust. For example, splitting the URL, getting the key/value pairs into an array, removing those you don't want (or removing everything except those you want) and recreating the URL.

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$url = "http://www.example.com/?new=yes&color=red&shape=square";

$url_parts = explode("&", $url);

$thePartYouWant = $url_parts[0];

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I would recommend the combination of parse_url & parse_str. You can also use http_build_url & http_build_str, though these require pecl_http.