Question

Could anyone explain the following line please?

RewriteRule ^(.*)$ /index.php/$1 [L]

Answer 1

The parts of the rewrite rule break down as follows:

1. RewriteRule
   Indicates this line will be a rewrite rule, as opposed to a rewrite condition or one of the other rewrite engine directives

2. ^(.*)$
   Matches all characters (.*) from the beggining ^ to the end $ of the request

3. /index.php/$1
   The request will be re-written with the data matched by (.*) in the previous example being substituted for $1.

4. [L]
   This tells mod_rewrite that if the pattern in step 2 matches, apply this rule as the “Last” rule, and don’t apply anymore.

The mod_rewrite documentation is really comprehensive, but admittedly a lot to wade through to decode such a simple example.

The net effect is that all requests will be routed through index.php, a pattern seen in many model-view-controller implementations for PHP. index.php can examine the requested URL segments (and potentially whether the request was made via GET or POST) and use this information to dynamically invoke a certain script, without the location of that script having to match the directory structure implied by the request URI.

For example, /users/john/files/index might invoke the function index('john') in a file called user_files.php stored in a scripts directory. Without mod_rewrite, the more traditional URL would probably use an arguably less readable query string and invoke the file directly: /user_files.php?action=index&user=john.