来自$ _SERVER ['HTTP_REFERER']的结果，当referer标头未发送到服务器时 [英] Result from $_SERVER['HTTP_REFERER'], when referer header is not sent to server

问题描述

当浏览器向服务器发送标题信息时， $ _ SERVER ['HTTP_REFERER'] 应该为我们提供上一页网址吗？

When the browser sends header info to the server, $_SERVER['HTTP_REFERER'] should give us the previous page URL right?

当头信息没有发送到服务器时，从 $ _ SERVER ['HTTP_REFERER'] 返回什么？空字符串？假？空值？或者？？

What returns from $_SERVER['HTTP_REFERER'], when header info is not sent to server? empty string? false? null? or... ?

推荐答案

如果没有发送HTTP referer请求标头，那么 $ _ SERVER [ 'HTTP_REFERER'] 可能未设置，尽管它可能是一个空字符串。在这种情况下是否设置可能取决于服务器。

If the HTTP referer request header is not sent then the $_SERVER['HTTP_REFERER'] is probably not set, although it could be an empty string. Whether it is set or not in this case could depend on the server.

与所有HTTP请求标头一样，在阅读时检查它是否存在：

As with all HTTP request headers, check for its existence when reading:

$httpReferer = isset($_SERVER['HTTP_REFERER']) ? $_SERVER['HTTP_REFERER'] : null;

这篇关于来自$ _SERVER ['HTTP_REFERER']的结果，当referer标头未发送到服务器时的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！