php代码麻烦帮忙解释下用C#代码实现

[又醒着到清晨]

第一段：

include dirname(__FILE__) . DIRECTORY_SEPARATOR . '_cookie_name.php';
$cookie_name = evercookie_get_cookie_name(__FILE__);

// 	
if (empty($_COOKIE[$cookie_name])) {
    // read our etag and pass back
    if (!function_exists('apache_request_headers')) {
        function apache_request_headers() {
            // Source: http://www.php.net/manual/en/function.apache-request-headers.php#70810
            $arh = array();
            $rx_http = '/\AHTTP_/';
            foreach ($_SERVER as $key => $val) {
                if (preg_match($rx_http, $key)) {
                    $arh_key = preg_replace($rx_http, '', $key);
                    $rx_matches = array();
                    // do some nasty string manipulations to restore the original letter case
                    // this should work in most cases
                    $rx_matches = explode('_', $arh_key);
                    if (count($rx_matches) > 0 and strlen($arh_key) > 2) {
                        foreach ($rx_matches as $ak_key => $ak_val) {
                            $rx_matches[$ak_key] = ucfirst(strtolower($ak_val));
                        }
                        $arh_key = implode('-', $rx_matches);
                    }
                    $arh[$arh_key] = $val;
                }
            }
            return ($arh);
        }
    }

    // Headers might have different letter case depending on the web server.
    // So, change all headers to uppercase and compare it.
    $headers = array_change_key_case(apache_request_headers(), CASE_UPPER);
    if(isset($headers['IF-NONE-MATCH'])) {
        // extracting value from ETag presented format (which may be prepended by Weak validator modifier)
        $etag_value = preg_replace('|^(W/)?"(.+)"$|', '$2', $headers['IF-NONE-MATCH']);
        header('HTTP/1.1 304 Not Modified');
        header('ETag: "' . $etag_value . '"');
        echo $etag_value;
    }
    exit;
}

// set our etag
header('ETag: "' . $_COOKIE[$cookie_name] . '"');
echo $_COOKIE[$cookie_name];

第二段：

// we get cookie name from current file name so remember about it when rename of this file will be required 
include dirname(__FILE__) . DIRECTORY_SEPARATOR . '_cookie_name.php';
$cookie_name = evercookie_get_cookie_name(__FILE__);

// we don't have a cookie, user probably deleted it, force cache
if (empty($_COOKIE[$cookie_name])) {
    header('HTTP/1.1 304 Not Modified');
    exit;
}

header('Content-Type: text/html');
header('Last-Modified: Wed, 30 Jun 2010 21:36:48 GMT');
header('Expires: Tue, 31 Dec 2030 23:30:45 GMT');
header('Cache-Control: private, max-age=630720000');

echo $_COOKIE[$cookie_name];

第三段：

// we get cookie name from current file name so remember about it when rename of this file will be required
include dirname(__FILE__) . DIRECTORY_SEPARATOR . '_cookie_name.php';
$cookie_name = evercookie_get_cookie_name(__FILE__);

// we don't have a cookie, user probably deleted it, force cache
if (empty($_COOKIE[$cookie_name])) {
    if(!headers_sent()) {
        header('HTTP/1.1 304 Not Modified');
    }
    exit;
}

// width of 200 means 600 bytes (3 RGB bytes per pixel)
$x = 200;
$y = 1;

$gd = imagecreatetruecolor($x, $y);

$data_arr = str_split($_COOKIE[$cookie_name]);

$x = 0;
$y = 0;
for ($i = 0, $i_count = count($data_arr); $i < $i_count; $i += 3) {
    $red   = isset($data_arr[$i])   ? ord($data_arr[$i])   : 0;
    $green = isset($data_arr[$i+1]) ? ord($data_arr[$i+1]) : 0;
    $blue  = isset($data_arr[$i+2]) ? ord($data_arr[$i+2]) : 0;
    $color = imagecolorallocate($gd, $red, $green, $blue);
    imagesetpixel($gd, $x++, $y, $color);
}

if(!headers_sent()) {
    header('Content-Type: image/png');
    header('Last-Modified: Wed, 30 Jun 2010 21:36:48 GMT');
    header('Expires: Tue, 31 Dec 2030 23:30:45 GMT');
    header('Cache-Control: private, max-age=630720000');
}

// boom. headshot.
imagepng($gd);

[又醒着到清晨]

引用 1 楼 xuzuning 的回复:

缺少 evercookie_get_cookie_name 函数定义！

是我代码不全吗？

[xuzuning]

缺少 evercookie_get_cookie_name 函数定义！

[又醒着到清晨]

https://github.com/samyk/evercookie/tree/master/php

[又醒着到清晨]

引用 1 楼 xuzuning 的回复:

缺少 evercookie_get_cookie_name 函数定义！

不好意思是漏写了：

function evercookie_get_cookie_name($file_name) {
    if (!empty($_GET['cookie'])) {
        return $_GET['cookie'];
    }
    return basename($file_name, '.php');
}

[丑肥宅]

引用 3 楼 又醒着到清晨 的回复:

https://github.com/samyk/evercookie/tree/master/php

楼主现在还在菲律宾吗