php - $_SERVER ['HTTP_REFERER'] 丢失

Question

我想在我的站点中使用 $_SERVER['HTTP_REFERER'] 但我得到以下信息:

Notice: Undefined index: HTTP_REFERER 

我试过打印 $_SERVER。这将输出以下内容:

Array
(
    [HTTP_HOST] => 192.168.1.10
    [HTTP_USER_AGENT] => Mozilla/5.0 (X11; Ubuntu; Linux i686; rv:15.0) Gecko/20100101 Firefox/15.0
    [HTTP_ACCEPT] => text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
    [HTTP_ACCEPT_LANGUAGE] => en-us,en;q=0.5
    [HTTP_ACCEPT_ENCODING] => gzip, deflate
    [HTTP_CONNECTION] => keep-alive
    [PATH] => /sbin:/usr/sbin:/bin:/usr/bin
    [SERVER_SIGNATURE] => Apache/2.2.3 (CentOS) Server at 192.168.1.10 Port 80
    [SERVER_SOFTWARE] => Apache/2.2.3 (CentOS)
    [SERVER_NAME] => 192.168.1.10
    [SERVER_ADDR] => 192.168.1.10
    [SERVER_PORT] => 80
    [REMOTE_ADDR] => 192.168.1.77
    [DOCUMENT_ROOT] => /var/www/html
    [SERVER_ADMIN] => root@localhost
    [SCRIPT_FILENAME] => /var/www/html/sandeep/test/hash.php
    [REMOTE_PORT] => 53851
    [GATEWAY_INTERFACE] => CGI/1.1
    [SERVER_PROTOCOL] => HTTP/1.1
    [REQUEST_METHOD] => GET
    [QUERY_STRING] => 
    [REQUEST_URI] => /sandeep/test/hash.php
    [SCRIPT_NAME] => /sandeep/test/hash.php
    [PHP_SELF] => /sandeep/test/hash.php
    [REQUEST_TIME] => 1347365919
)

任何人都可以帮我找到 HTTP_REFERER 或建议替代 HTTP_REFERER 吗？

Answer 1

来自文档:

The address of the page (if any) which referred the user agent to the current page. This is set by the user agent. Not all user agents will set this, and some provide the ability to modify HTTP_REFERER as a feature. In short, it cannot really be trusted.

http://php.net/manual/en/reserved.variables.server.php