PHP：$ _SERVER ['REDIRECT_URL'] vs $ _SERVER ['REQUEST_URI']

Question

I printed $_SERVER, and I found out that $ _SERVER['REDIRECT_URL'] vs $_SERVER['REQUEST_URI'] both have same values. What's the difference between the two?

Answer 1

REQUEST_URI is the requested URI path and query as used in the HTTP request line . REDIRECT_URL is created by Apache when an internal redirect happens:

REDIRECT_ environment variables are created from the environment variables which existed prior to the redirect. They are renamed with a REDIRECT_ prefix, ie, HTTP_USER_AGENT becomes REDIRECT_HTTP_USER_AGENT .

REDIRECT_URL , REDIRECT_STATUS , and REDIRECT_QUERY_STRING are guaranteed to be set, and the other headers will be set only if they existed prior to the error condition.

Note that REDIRECT_URL does only contain the URI path.

Answer 2

$_SERVER['REDIRECT_URL'] is only available on some servers in some cases. Use $_SERVER['REQUEST_URI'] instead.

Answer 3

REQUEST_URI还将空格等特殊字符更改为“％20”等。