Recently, I am working on the system log function, and I need to get the ip of the logged in user, and the system is the function $request->ip() that TP5 already has to get the ip. Then I analyzed the function step by step in the interest and added a comment
/**
* Get client IP address
* @param integer $type Return type 0 Return IP address 1 Return IPV4 address number
* @param boolean $adv whether to obtain advanced mode (may be disguised)
* @return mixed
*/
public function ip($type = 0, $adv = false)
{
$type = $type ? 1 : 0; //Regularly judge whether to pass in the type=1 parameter, and then find the ipv4 address number
static $ip = null; //Define as a static variable to prevent repeated calls
if (null !== $ip) {
return $ip[$type];
}
/*
* There are several ways to get the client ip. When the user uses a proxy server, through $_SERVER['HTTP_X_FORWARDED_FOR'] or
* $_SERVER['HTTP_CLIENT_IP'] to get, of course, the way to get ip not only includes these, but also getnv('REMOTE_ADDR'), etc.
* */
if ($adv) {
/ / Determine whether the user passes parameters to determine how to obtain the ip
if (isset($_SERVER['HTTP_X_FORWARDED_FOR'])) {
$arr = explode(',', $_SERVER['HTTP_X_FORWARDED_FOR']); //Wait until proxy ip and user's local ip
$pos = array_search('unknown', $arr); //Filter and judge the obtained value
if (false !== $pos) {
unset($arr[$pos]);
}
$ip = trim(current($arr));
} 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 address legal verification
$long = sprintf("%u", ip2long($ip));
$ip = $long ? [$ip, $long] : ['0.0.0.0', 0];
return $ip[$type];
}