php常用代码片段

1,获取用户真实ip

public function get_client_ip( $type = 0, $adv = true ) {
$type= $type ? 1 : 0;
static $ip = NULL;
if ($ip !== NULL) return $ip[$type];
if($adv){
if (isset($_SERVER['HTTP_X_FORWARDED_FOR'])) {
$arr = explode(',', $_SERVER['HTTP_X_FORWARDED_FOR']);
$pos = array_search('unknown',$arr);
if(false !== $pos) unset($arr[$pos]);
$ip = trim($arr[0]);
}elseif (isset($_SERVER['HTTP_CLIENT_IP'])) {
$ip = $_SERVER['HTTP_CLIENT_IP'];
}elseif (isset($_SERVER['REMOTE_ADDR'])) {
$ip = $_SERVER['REMOTE_ADDR'];
}
}elseif (isset($_SERVER['REMOTE_ADDR'])) {
$ip = $_SERVER['REMOTE_ADDR'];
}
// IP地址合法验证
$long = sprintf("%u",ip2long($ip));
$ip = $long ? array($ip, $long) : array('0.0.0.0', 0);
return $ip[$type];
}