uri 定义

function path(){
   $path=explode("/",$_SERVER['REQUEST_URI']);
   unset($path[(count($path)-1)]);
   $path=implode("/",$path);
   return $path;
}

function r($targe=null){
   if(is_null($targe)){
      if(isset($_SERVER['HTTP_REFERER'])){
         return $_SERVER['HTTP_REFERER'];
      }else{
         $targe=path();
      }
   }else{
      if(substr($targe,0,4)!='http'){
         if(substr($targe,0,1)!='/'){
            $targe=path().'/'.$targe;
         }else{
            $targe=path().$targe;
         }

      }else{
         return $targe;
      }
   }
   if(in_array('https',$_SERVER)&&$_SERVER['HTTPS']=='ON'){
      return 'https://'.$_SERVER['HTTP_HOST'].$targe;
   }else{
      return 'http://'.$_SERVER['HTTP_HOST'].$targe;
   }

}
echo  r("aaa");