PHP IP地址与整型互相转换详解

$ip = '210.110.11.49';

echo ip2long($ip);

输出：

-764540111

$ip = '210.110.11.49';

$ip_int = ip2long($ip);

echo $ip."<br />";

echo $ip_int."<br />";

echo long2ip($ip_int);

输出：

210.110.11.49
-764540111
210.110.11.49

$ip = '210.110.011.49';

$ip_int = ip2long($ip);

echo $ip."<br />";

echo $ip_int."<br />";

echo long2ip($ip_int);

输出：

210.110.011.49
-764540623
210.110.9.49

$ip = '021.110.11.49';

$ip_int = ip2long($ip);

echo $ip."<br />";

echo $ip_int."<br />";

echo long2ip($ip_int);

输出：

021.110.11.49
292424497
17.110.11.49

$ip = '0210.110.11.49';

function ipToInt($ip){

$iparr = explode('.',$ip);

$num = 0;

for($i=0;$i<count($iparr);$i++){

$num += intval($iparr[$i]) * pow(256,count($iparr)-($i+1));

}

return $num;

}

echo $ip.'<br />';

$ip_int = ipToInt($ip);

echo $ip_int.'<br />';

echo long2ip($ip_int);

输出：

0210.110.11.49
3530427185
210.110.11.49

$ip = '0210.110.11.49';

function ipToInt($ip){

$iparr = explode('.',$ip);

return (intval($iparr[0]<<24))|(intval($iparr[1])<<16)|(intval($iparr[2])<<8)| (intval($iparr[3]));

}

echo $ip.'<br />';

$ip_int = ipToInt($ip);

echo $ip_int.'<br />';

echo long2ip($ip_int);

输出：

0210.110.11.49
-764540111
210.110.11.49

function check_ip($ip){

$iparr = explode('.',$ip);

foreach($iparr as $v){ if($v>255) return false; }

return true;

}

echo '210.285.11.49,';

var_dump(check_ip('210.285.11.49'));

echo '<br />';

echo '210.205.11.49,';

var_dump(check_ip('210.205.11.49'));

输出：

210.285.11.49,bool(false)
210.205.11.49,bool(true)

function check_ip($ip){

if(ip2long($ip)) return true;

return false;

}

echo '210.285.11.49,';

var_dump(check_ip('210.285.11.49'));

echo '<br />';

echo '210.205.11.49,';

var_dump(check_ip('210.205.11.49'));

输出：

210.285.11.49,bool(false)
210.205.11.49,bool(true)

{"code":0,"data":{"country":"u7f8eu56fd","country_id":"US","area":"","area_id":"","region":"","region_id":"","city":"","city_id":"","county":"","county_id":"","isp":"","isp_id":"","ip":"8.8.8.8"}}

/**
 * 获取 IP  地理位置
 * 淘宝IP接口
 * @Return: array
 */
function getCity($ip)
{
$url="http://ip.taobao.com/service/getIpInfo.php?ip=".$ip;
$ip=json_decode(file_get_contents($url));
if((string)$ip->code=='1'){
  return false;
  }
  $data = (array)$ip->data;
return $data;
}

function getIP()
{
    static $realip;
    if (isset($_SERVER)){
        if (isset($_SERVER["HTTP_X_FORWARDED_FOR"])){
            $realip = $_SERVER["HTTP_X_FORWARDED_FOR"];
        } else if (isset($_SERVER["HTTP_CLIENT_IP"])) {
            $realip = $_SERVER["HTTP_CLIENT_IP"];
        } else {
            $realip = $_SERVER["REMOTE_ADDR"];
        }
    } else {
        if (getenv("HTTP_X_FORWARDED_FOR")){
            $realip = getenv("HTTP_X_FORWARDED_FOR");
        } else if (getenv("HTTP_CLIENT_IP")) {
            $realip = getenv("HTTP_CLIENT_IP");
        } else {
            $realip = getenv("REMOTE_ADDR");
        }
    }
 
 
    return $realip;
}

<?php
$a = 1;
$b = 2;

function Sum()
{
    global $a, $b; //在里面声明为全局变量

    $b = $a + $b;
}

Sum();
echo $b;
?>

 <?PHP
      $w3sky = 1;
      $w3sky2 = 2;

function Sum()
       {
       global $w3sky, $w3sky2;$w3sky2 = $w3sky + $w3sky2;
       }Sum();
       echo $w3sky2;
       ?>

HTTP/1.1 200 OK
Date: Tue, 03 Mar 2009 04:58:40 GMT
Content-Type: image/jpeg
Content-Length: 83185
Last-Modified: Tue, 24 Feb 2009 08:01:04 GMT
Cache-Control: max-age=2592000
Expires: Thu, 02 Apr 2009 05:14:08 GMT
Etag: “5d8c72a5edda8d6a:3239″

HTTP/1.x 304 Not Modified
Date: Tue, 03 Mar 2009 05:03:56 GMT
Content-Type: image/jpeg
Content-Length: 83185
Last-Modified: Tue, 24 Feb 2009 08:01:04 GMT
Cache-Control: max-age=2592000
Expires: Thu, 02 Apr 2009 05:14:08 GMT
Etag: “5d8c72a5edda8d6a:3239″

header(’Cache-Control: max-age=86400,must-revalidate’);
header(’Last-Modified: ‘ .gmdate(’D, d M Y H:i:s’) . ‘ GMT’ );
header(”Expires: ” .gmdate (’D, d M Y H:i:s’, time() + ‘86400′ ). ‘ GMT’);

cache();
echo date(”Y-m-d H:i:s”);
function cache()
{
       $etag = “http://longrujun.name”;
       if (isset($_SERVER['HTTP_IF_NONE_MATCH'])  &&
$_SERVER['HTTP_IF_NONE_MATCH'] == $etag)
       {
              header(’Etag:’.$etag,true,304);
              exit;
       }
       else header(’Etag:’.$etag);
}

$imagePath = "path/to/some/image";
 
$eTag = $imagePath;
$eTag .= fileMTime($imagePath);
$eTag = md5($eTag);
 
if((isset($_SERVER['HTTP_IF_NONE_MATCH'])) &&
(stripslashes($_SERVER['HTTP_IF_NONE_MATCH']) == $eTag)) {
    header("HTTP/1.1 304 Not Modified", TRUE, 304);
    exit();
}
 
header("ETag: ".$eTag);
header("Content-Type: image/png");
readFile($imagePath);
exit();

$fullpath = '/www/images/' . basename($_GET['img']); //假定文件都在/www/images/下
if (!is_file($fullpath)) {
    header("HTTP/1.0 404 Not Found");
    exit();
}
 
$info = getImageSize($fullpath); //获取图片信息
if (!$info) {                    //如果不是图片
    header("HTTP/1.0 404 Not Found");
    exit();
}
 
// 以下凡是header函数都是在输出头部信息。较多。
header('Content-type: '. $info['mime']);          //类似于image/png
header('Content-Length: '. filesize($fullpath));  //文件长度
 
header('Pragma: ');             //没用，但要设置，防止服务器生成no-cache的可怕字眼
 
//手动设置过期时间，单位都是秒
$validtime = 48* 60 * 60;    // 48小时
 
//缓存相对请求的时间，
header('Cache-Control: ' . 'max-age='. $validtime);
 
//也很重要的Expires头，功能类似于max-age
//time()+$validtime: 设置期限，到期后才会向服务器提交请求
//gmdate，生成Sun, 01 Mar 2009 04:05:49 +0000  的字符串，而且是GMT标准时区
//preg_replace,  生成Sun, 01 Mar 2009 04:05:49 GMT， 注意：可能与服务器设置有关，
//但我都用默认设置
header('Expires:'. preg_replace('/.{5}$/', 'GMT', gmdate('r', time()+ $validtime)));
 
//文件最后修改时间
$lasttime = filemtime($fullpath);
 
//最后修改时间，设置了，点击刷新时，浏览器再次请求图片才会发出'IF_MODIFIED_SINCE'头，
//从而被php程序读取
header('Last-Modified: ' . preg_replace('/.{5}$/', 'GMT', gmdate('r', $lasttime) ));
 
//重要，如果请求中的时间和 文件生成时间戳相等，则文件未修改，客户端可用缓存
if (strtotime($_SERVER['HTTP_IF_MODIFIED_SINCE']) == $lasttime) {
    header("HTTP/1.1 304 Not Modified"); //服务器发出文件不曾修改的指令
    exit();
}
 
//如果文件被修改了，只好重新发出数据
echo file_get_contents($fullpath);