php/html - http_referer
我正在创建一个网站，在一个特定页面上，我想将用户返回到上一页。 我对 PHP/HTML 相当陌生，并且一直在使用一些现有代码来获取想法和帮助。
现有代码使用以下方法：
if (! empty($HTTP_REFERER))
{
header("Location: $HTTP_REFERER");
} else
{
header("Location: $CFG->wwwroot");
}
但是，当我使用此代码时，HTTP_referer 始终被视为空，并且用户重定向到根页面。 这段代码有什么明显的缺陷吗？
I am creating a website and on one particular page, am wanting to send the user back to the previous page. I am fairly new to PHP/HTML and have been using some existing code for ideas and help.
The existing code uses the following method:
if (! empty($HTTP_REFERER))
{
header("Location: $HTTP_REFERER");
} else
{
header("Location: $CFG->wwwroot");
}
However, when I use this code the HTTP_referer is always treated as empty and the user redirected to the root page. Any obvious flaws in this code?
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不要依赖 HTTP Referrer 为有效字段甚至非空字段。 人们可以选择不设置此设置，从而将该变量的任何检查保留到 IF-ELSE 子句的空侧。
您可以通过在 URL 或 POST 参数中发送一个参数来防止这种情况，该参数将包含一个可用于将用户重定向回的值。
Don't rely on the HTTP Referrer being a valid or even non-empty field. People can choose to not have this set leaving any checks for that variable going to the empty side of the IF-ELSE clause.
You can guard against this by sending along a parameter in either the URL or POST parameters that would hold a value that you can use to redirect the user back to.
您需要使用：
You need to use:
isset($_SERVER['HTTP_REFERER']) ？ $_SERVER['HTTP_REFERER'] : '';
isset($_SERVER['HTTP_REFERER']) ? $_SERVER['HTTP_REFERER'] : '';
如果您想将用户发送回上一页并使其正常工作，而不管引荐来源是否设置正确，您可以将 GET 参数附加到 URL（或 POST）..您将需要对 URL 进行编码..类似
http://www.domain.com.au/script.php?return=http%3a%2f%2fwww.domain.com.au%2fthis-is-where-i-was%2f< /a>
您可以使用 PHP 的 urlencode() 函数。
If you wanted to send the person back to the previous page and have it work regardless of the referrer being set correctly, you can append a GET parameter to the URL (or POST).. you will need to encode the URL.. Something like
http://www.domain.com.au/script.php?return=http%3a%2f%2fwww.domain.com.au%2fthis-is-where-i-was%2f
You can use PHP's
urlencode()function.另请注意，引用标头可能为空或丢失，因此您根本不应该依赖它。
Also note that the referer header might be empty or missing anyway, so you shouldn't rely on it at all..
你应该使用
但是查看php.ini中的register_globals配置，由于安全原因应该将其关闭。 您可以在PHP 手册网站上阅读更多信息。
You should use
However look at the register_globals configuration in php.ini, it should be turned off due to security reasons. You can read more on PHP Manual site.