The example in this paper describes how PHP realizes whether the access route is a search engine robot. Share to everyone for your reference. The specific analysis is as follows: 
 
Many times we need to identify the site visitors, for real users and search engines for different actions to achieve, then the first need to determine whether it is a search engine.
 
PHP Judgment method is very simple, by filtering $_server[' http_user_agent ' parameters can be identified, the following is an excerpt from an open source program related source code:
 
 
Private Function Getrobot () {if (Empty ($_server[' http_user_agent ')) {  return false;} $searchEngineBot = Array (  ' googlebot ' = ' Google ',  ' mediapartners-google ' and ' Google ', ' baiduspider ' and '  Baidu ',  ' MSNBot ' + ' MSN ',  ' yodaobot ' = ' Yodao ',  ' Youdaobot ' and ' Yodao ',  ' Yahoo! slurp ' and ' Yahoo ',  ' Yahoo! slurp china ' = ' yahoo ',  ' iaskspider ' = ' iask ',  ' Sogou web spider ' = ' sogou ',  ' Sogou push spider ' = ' sogou ',  ' sosospider ' = ' Soso ',  ' spider ' = ' other ',  ' crawler ' and ' = ' Other ',); $spider = Strtolower ($_server[' http_user_agent '); foreach ($searchEngineBot as $key = + $value) {   if (Strpos ($spider, $key)!== false)  {   return $value; c18/>}} return false;} Public Function Isrobot () {if ($this->getrobot ()!==false) {  return true;} return false;}
 
 
I hope this article is helpful to everyone's PHP programming.