/**
 *$ip  string  必传
 *获取ip归属地 
 *demo 四川省成都市 电信 
 */
function get_ip_city($ip)
{
    $ch = curl_init();
    $url = 'https://whois.pconline.com.cn/ipJson.jsp?ip=' . $ip;
    //用curl发送接收数据
    curl_setopt($ch, CURLOPT_URL, $url);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    //请求为https
    curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
    curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, false);
    $location = curl_exec($ch);
    curl_close($ch);
    //转码
    $location = mb_convert_encoding($location, 'utf-8', 'GB2312');
    //var_dump($location);
    //截取{}中的字符串
    $location = substr($location, strlen('({') + strpos($location, '({'), (strlen($location) - strpos($location, '})')) * (-1));
    //将截取的字符串$location中的‘，’替换成‘&’   将字符串中的‘：‘替换成‘=’
    $location = str_replace('"', "", str_replace(":", "=", str_replace(",", "&", $location)));
    //php内置函数，将处理成类似于url参数的格式的字符串  转换成数组
    parse_str($location, $ip_location);
    return $ip_location['addr'];
}