How PHP obtains the IP of the client and the province

How PHP obtains the client's IP and the local province
For specific implementation code. Thank you..

------Solution--------------------

Provides several IP address APIs

Sina's IP address query interface: HTTP://INT.DPOOL.SINA.COM.CN/IPLOOKUP/IPLOOKUP.PHP?FORMAT=JS
Sina another IP address query interface: HTTP://COUNTER.SINA.COM.CN/IP
Sina Multi-Region test method: http://int.dpool.sina.com.cn/iplookup/iplookup.php?format=js&ip=218.192.3.42
Sohu IP Address Query interface (default GBK): Http://pv.sohu.com/cityjson
Sohu IP Address Query interface (can be set code): Http://pv.sohu.com/cityjson?ie=utf-8
Sohu additional IP Address query interface: HTTP://TXT.GO.SOHU.COM/IP/SOIP
------Solution--------------------
1. You can build your own IP library, data can be extracted from a packet like innocence

2. Get the IP code online a whole bunch of copies here one

function GetIP ()
{
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);
}

3. The IP can be passed to some of the currently available online interface to obtain the data returned to parse it

For example
http://int.dpool.sina.com.cn/iplookup/iplookup.php?format=js&ip=219.136.252.33

Note the IP address of the visitor is automatically obtained if the IP is not delivered.

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