获取访问者IP（PHP代码函数）

//获取访问者IP（PHP代码函数）//代码来源：Monxin ./config/functions.phpfunction get_ip(){if(getenv("HTTP_CLIENT_IP") && strcasecmp(getenv("HTTP_CLIENT_IP"),"unknown")){  $ip=getenv("HTTP_CLIENT_IP");}else if (getenv("HTTP_X_FORWARDED_FOR") && strcasecmp(getenv("HTTP_X_FORWARDED_FOR"),"unknown")){  $ip=getenv("HTTP_X_FORWARDED_FOR");}else if (getenv("REMOTE_ADDR") && strcasecmp(getenv("REMOTE_ADDR"),"unknown")){  $ip=getenv("REMOTE_ADDR");}else if (isset($_SERVER['REMOTE_ADDR']) && $_SERVER['REMOTE_ADDR'] && strcasecmp($_SERVER['REMOTE_ADDR'],"unknown")){  $ip=$_SERVER['REMOTE_ADDR'];}else{  $ip="unknown" ;  }return $ip;  }