<?php    class keyword{       public function getKeyword($referer){          if(strpos($referer,"http://www.baidu.com")> -1 ){              $keyword = $this->getbaidukeyword($referer);          }else if(strpos($referer,"http://www.google.com")> -1 ){              $keyword = $this->getgooglekeyword($referer);          }else if(strpos($referer,"http://www.soso.com")> -1 ){              $keyword = $this->getsosokeyword($referer);          }else if(strpos($referer,"http://www.sogou.com")> -1 ){              $keyword = $this->getsogoukeyword($referer);          }                    return $keyword;      }           //由来路取得百度关键词      private function getbaidukeyword($str){          $s = strpos($str,‘wd=‘);          if($s>-1){              $str = substr($str,$s+3);              $e = strpos($str,‘&‘);              if($e>-1){                  $str = substr($str,0,$e);              }              $str = rawurldecode($str);          }          return $str;      }      //获得谷歌关键词      private function getgooglekeyword($str){          $s = strpos($str,‘&q=‘);          if($s>-1){              $str = substr($str,$s+3);              $e = strpos($str,‘&‘);              if($e>-1){                  $str = substr($str,0,$e);              }              $str = rawurldecode($str);          }          return $str;      }      //获得SOSO关键词      private function getsosokeyword($str){          $s = strpos($str,‘?w=‘);          if($s>-1){              $str = substr($str,$s+3);              $e = strpos($str,‘&‘);              if($e>-1){                  $str = substr($str,0,$e);              }              $str = rawurldecode($str);          }else{              $s = strpos($str,‘&w=‘);              if($s>-1){                  $str = substr($str,$s+3);                  $e = strpos($str,‘&‘);                  if($e>-1){                      $str = substr($str,0,$e);                  }                  $str = rawurldecode($str);              }          }          return $str;      }      //获得sogou关键词      private function getsogoukeyword($str){          $s = strpos($str,‘query=‘);          if($s>-1){              $str = substr($str,$s+6);              $e = strpos($str,‘&‘);              if($e>-1){                  $str = substr($str,0,$e);              }              $str = rawurldecode($str);          }          return $str;      }  }?>