php根据ip地址获取地理位置

目前我测试过的有三种方法可以根据ip地址获取地理位置，第一种是通过新浪IP查询接口获取，第二种是通过腾讯IP查询接口获取，第三种是通过ip138查询。

一、新浪IP查询接口地址：http://int.dpool.sina.com.cn/iplookup/iplookup.php

后面带有两个参数：ip=你要查询的ip地址，format=返回的查询结果格式，现在使用json

	function getAddressFromIp_sina($ip) {
		$url = "http://int.dpool.sina.com.cn/iplookup/iplookup.php?format=json&ip=".$ip;
		$ch = curl_init();
		curl_setopt($ch, CURLOPT_URL, $url);
		curl_setopt($ch, CURLOPT_TIMEOUT, 10);
		curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
		$addr = curl_exec($ch);
		$data = json_decode($addr);
		curl_close($ch);

		if($data->ret == "1") {
			$result = $data->province.",".$data->city.",".$data->isp;
		} else {
			$result = "未能定位成功";
		}

		return $result;
	}

二、腾讯IP查询接口地址：http://ip.qq.com/cgi-bin/searchip

后面带有一个参数：searchip1=你要查询的ip地址

	function getAddressFromIp_tencent($ip) {
		$url = "http://ip.qq.com/cgi-bin/searchip?searchip1=".$ip;
		$ch = curl_init();
		curl_setopt($ch, CURLOPT_URL, $url);
		curl_setopt($ch, CURLOPT_ENCODING, 'GB2312');
		curl_setopt($ch, CURLOPT_TIMEOUT, 10);
		curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
		$data = curl_exec($ch);
		$data = mb_convert_encoding($data, "UTF-8", "GB2312");
		curl_close($ch);
		print_r($data);
	}

这种方式刚开始是成功的，后来一直返回空，原因还在寻找...

三、IP138 IP查询接口地址：http://www.ip138.com/ips138.asp

后面带有一个参数：ip=你要查询的ip地址

	function getAddressFromIp_ips($ip) {
		$url = "http://www.ip138.com/ips138.asp?ip=".$ip;
		$ch = curl_init($url);
		curl_setopt($ch, CURLOPT_ENCODING, "GB2312");
		curl_setopt($ch, CURLOPT_TIMEOUT, 10);
		curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
		$data = curl_exec($ch);
		$data = mb_convert_encoding($data, "UTF-8", "GB2312");
		curl_close($ch);
		preg_match("/本站主数据：.*<\/li>
/", $data, $result);
		print_r($result);
	}