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.htaccessmod-rewrite

Mod_rewrite only working with certain folder names

Context

I'm using mod_rewrite to make my links better for SEO. I made the following rule for my page expanded_debate.php:

Options -MultiViews

RewriteEngine on

RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME}\.php -f
RewriteRule ^poll/([0-9a-zA-Z_-]+)/([0-9]+) expanded_debate.php?poll_title=$1&pollid=$2 [NC,QSA,L]

When I input this format in the URL (poll/filename/10, for example) I get a 404 error:

Object not found!
The requested URL was not found on this server. If you entered the URL manually please check your spelling and try again.

If you think this is a server error, please contact the webmaster.

Error 404
localhost
Apache/2.4.46 (Unix) OpenSSL/1.1.1h PHP/7.4.12 mod_perl/2.0.11 Perl/v5.32.0

However, when I change the first folder name to certain words, such as "debate" and "expanded_debate" (but not "expandedebate"), the file loads after page refresh. For example:

RewriteRule ^debate/([0-9a-zA-Z_-]+)/([0-9]+) expanded_debate.php?poll_title=$1&pollid=$2 [NC,QSA,L]

works fine.

I have an older .htaccess file, titled ".htaccess11", with the following info, in case it's of any use:

#forbids users from going to forbidden pages
IndexIgnore *

Options -Indexes
RewriteEngine On
RewriteCond %{SERVER_PORT} !^443$
RewriteCond %{REQUEST_URI} !^/\.well-known/acme-challenge/[0-9a-zA-Z_-]+$
RewriteCond %{REQUEST_URI} !^/\.well-known/cpanel-dcv/[0-9a-zA-Z_-]+$
RewriteCond %{REQUEST_URI} !^/\.well-known/pki-validation/(?:\ Ballot169)?
RewriteCond %{REQUEST_URI} !^/\.well-known/pki-validation/[A-F0-9]{32}\.txt(?:\ Comodo\ DCV)?$
RewriteRule ^(.*)$ https://%{SERVER_NAME}%{REQUEST_URI} [R=301,L]

#404 error directions
ErrorDocument 404 /404.php

Question

Any idea why only certain terms in the first folder position ("^debate" in example above) work when using mod_rewrite?

There are no "poll" folders in my project, if that's of any interest.

Let me know if there are any questions.

Solution

  • The line

    RewriteCond %{REQUEST_FILENAME}\.php -f

    Means "Take the requested URL, map it to a full local path in the normal way, append .php to the resulting path, and then process the following rewrite rule only if there is an existing regular file at the modified path".

    For example, the URL "poll/filename/10" will be rewritten only if there is a file called "poll/filename/10.php" in the relevant location.

    Since the value of the AcceptPathInfo directive is evidently set to On, this condition will also be met if there is an existing file called "poll.php" or "poll/filename.php". That is why the rewrite rule works when you change "poll" to "debate" or "expanded_debate" – there are existing files called "debate.php" and "expanded_debate.php".

    In any case, it sounds like this behavior is not what was intended. Removing the -f condition should give the desired result. Or, to prevent the rewrite rule from making existing files inaccessible, you could replace it with:

    RewriteCond %{REQUEST_FILENAME} !-f

    • The exclamation point negates the -f test: "continue only if this file does not exist"

    • If you are using the %{REQUEST_FILENAME} server variable (anywhere), you should be aware of how the AcceptPathInfo directive will affect this, and consider setting that directive explicitly in the same .htaccess file.

    • If Options +MultiViews is in effect, then %{REQUEST_FILENAME} will match existing files whether or not the extension is included in the request (GET /foo will match an existing file "foo.php", "foo.html", etc.). And GET /foo.php will match in any case. So, omit the string "\.php" from the original rule.

    • Other configuration may also have an effect, too. The important point is that, unlike %{REQUEST_URI}, %{REQUEST_FILENAME} invokes all the processing that Apache would otherwise do to translate a URL into a local path.

    (source)

    NB: although I don't think it was the intention here, you actually might want to test for the existence of a local file as part of this rule. You could use a RewriteCond to check whether the back-end data file for a given poll has been manually created, and return 404 by default if it has not. That would be a simple way to prevent users from making up their own poll URLs at will.