Seeking a search engine to route judgment code to jump to solve the method

Ask a search engine to route the code to jump
Ask the hero to write a search engine routing judgment code to jump
If it's Baidu, jump to http://aaaa.com.
If it's Google, it's going to http://bbbb.com.
If it's a sogou, jump to http://cccc.com.
Direct input will not jump
Thank you.

------Solution--------------------
I don't know what you're doing, or maybe it's just an industry, here's a case. I don't think you're going to get a link from baidu.com. Haha, so to use the actual war should be replaced by the way of the comparison. These are all self-improvement.

PHP Code

$RURL = $_server [' Http_referer '];if (! empty ($RURL)) {    $UArray = Parse_url ($RURL);    $UHost = $UArray [' host '];    Switch ($UHost) {case        ' www.baidu.com ':            header ("location:http://aaa.com");            break;        Case ' www.google.com ':            header ("location:http://bbb.com");            break;        Case ' www.sogou.com ':            header ("location:http://ccc.com");            break;        Default:            echo $UHost;            break;    }} echo ' direct input ';
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