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Accepted
Jeff
Asked: 2021-11-28 04:25:42 +0800 CST

What does %{REQUEST_FILENAME}.ext mean? Why the extra .ext ending?

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The %{REQUEST_FILENAME} contains a string like this:

/web/webroot/index.php

I see a lot of people recommend testing if a file exists and has a .php extension like this:

RewriteCond %{REQUEST_FILENAME}.php -f

Isn't the .php after %{REQUEST_FILENAME} redundant? The variable should already contain the .php, right?

Seems like adding .php after %{REQUEST_FILENAME} would make the TestString check add an extra .php, like this:

/web/webroot/index.php.php

I'm missing something simple, I'm sure of it, but I just don't know what it is.

The context is this:

RewriteCond %{THE_REQUEST} ^.*?\.php [NC]
RewriteRule ^ - [R=404,NE,L]

RewriteCond %{REQUEST_FILENAME}.php -f
RewriteRule ^ %{REQUEST_FILENAME}.php [L]
mod-rewrite apache-2.4

1 Answers

  1. Best Answer

    Isn't the .php after %{REQUEST_FILENAME} redundant? The variable should already contain the .php, right?

    Well, yes and no, it depends what you are trying to do.

    RewriteCond %{REQUEST_FILENAME}.php -f
RewriteRule ^ %{REQUEST_FILENAME}.php [L]

    This rule allows you to request extensionless URLs. eg. /index or /foo and this internally rewrites the request to /index.php and /foo.php respectively.

    In this instance, REQUEST_FILENAME is a string of the form /web/webroot/index. So, it's testing that /web/webroot/index.php exists before rewriting to the same. If you were to request /index.php then the condition fails and no rewrite occurs (which is correct).

    However, this rule isn't strictly correct and could cause a rewrite-loop under certain conditions. See the following related question:

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