PHP可靠地设置Etag

发布于 2024-09-14 04:34:29 字数 792 浏览 10 评论 0原文

我无法在用户浏览器上可靠地设置 Etag。当用户单击我的外部链接之一时，我想将文章 id 设置到他们的 Etag 中（我也使用 cookie，但 id 喜欢专门尝试 Etag 以测试其可靠性）。

当同一用户在几个小时/几天后返回我的网站时，我希望能够读取 Etag 值并将其用于其他用途。

我可以在初始点击时设置 Etag，但是当用户返回时，Etag 值就消失了。我猜它已经过期了或者什么的。这是我一直在尝试的代码：

<?

$time = 1280951171;
$lastmod = gmdate('D, d M Y H:i:s \G\M\T', $time);
$etag = '123';


$ifmod = isset($_SERVER['HTTP_IF_MODIFIED_SINCE']) ? $_SERVER['HTTP_IF_MODIFIED_SINCE'] == $lastmod : null; 
$iftag = isset($_SERVER['HTTP_IF_NONE_MATCH']) ? $_SERVER['HTTP_IF_NONE_MATCH'] == $etag : null; 

if (($ifmod || $iftag) && ($ifmod !== false && $iftag !== false)) { 
    header('HTTP/1.0 304 Not Modified'); 
} else {
    header("Last-Modified: $lastmod"); 
    header("ETag: $etag");
}

print_r($_SERVER);

?>

原文

im having trouble setting the Etag on a user's browser reliably. When a user clicks on one of my external links, i would like to set the article id into their Etag (i use cookies too, but id like to experiment with Etag specifically to test its reliability).

When the same user returns to my site a few hours/days later, i would like to be able to read the Etag value and use it for stuff.

I can set an Etag on the initial click, but when the user returns the Etag value is gone. I assume its expired or something. Here is the code i have been trying:

<?

$time = 1280951171;
$lastmod = gmdate('D, d M Y H:i:s \G\M\T', $time);
$etag = '123';


$ifmod = isset($_SERVER['HTTP_IF_MODIFIED_SINCE']) ? $_SERVER['HTTP_IF_MODIFIED_SINCE'] == $lastmod : null; 
$iftag = isset($_SERVER['HTTP_IF_NONE_MATCH']) ? $_SERVER['HTTP_IF_NONE_MATCH'] == $etag : null; 

if (($ifmod || $iftag) && ($ifmod !== false && $iftag !== false)) { 
    header('HTTP/1.0 304 Not Modified'); 
} else {
    header("Last-Modified: $lastmod"); 
    header("ETag: $etag");
}

print_r($_SERVER);

?>

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凡间太子 2024-09-21 04:34:29

您应该将您的 etag 用双引号括起来（如 Codler 提到的链接所示）：

'"' . $etag . '"'

我认为这不太可能解决您的问题，但您可能希望

header('Not Modified',true,304);

从

header('HTTP/1.0 304 Not Modified');

PHP 5.4 开始，有一种更好的方法可以使用 http_response_code：

http_response_code(304);

另外，您检查过吗对于常见的嫌疑人停止标头？ Unicode 字节顺序标记对此非常烦人。（如果您可以看到您自己设置的其他标题，请忽略）

You should be wrapping your etag in double quotes (as the link Codler mentioned shows):

'"' . $etag . '"'

I don't think it's likely to solve your problem, but you probably want

header('Not Modified',true,304);

instead of

header('HTTP/1.0 304 Not Modified');

As of PHP 5.4 there's a better way to do this with http_response_code:

http_response_code(304);

Also, have you checked for the usual suspects stopping headers? Unicode Byte-Order Markers are very annoying with this. (Disregard if you can see other headers you're setting yourself)

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