How to do URL re-writing in PHP?

Question

I am trying to implement URL rewriting in my PHP application. Can someone share a step by step procedure of implementing URL rewriting in PHP and MySQL?

In my application I want to implement following URL rewriting, I want to redirect

1. http://example.com/videos/play/google-io-2009-wave-intro
2. http://example.com/videos/play/203/google-io-2009-wave-intro

to

1. http://example.com/videos/play.php?title=google-io-2009-wave-intro
2. http://example.com/videos/play.php?id=203

Please tell me how to implement both URL rewriting in any of the above way.

One more thing which URL will be best according to SEO, management, application point-of-view out of the following two types.

1. http://example.com/videos/play/google-io-2009-wave-intro
2. http://example.com/videos/play/203/google-io-2009-wave-intro

Answer 1

A Beginner's Guide to mod_rewrite.

Typically this will be nothing more than enabling the mod_rewrite module (you likely already have it enabled with your host), and then adding a .htaccess file into your web-directory. Once you've done that, you are only a few lines away from being done. The tutorial linked above will take care of you.

Just for fun, here's a Kohana .htaccess file for rewriting:

# Turn on URL rewriting
RewriteEngine On

# Installation directory
RewriteBase /rootDir/

# Protect application and system files from being viewed
RewriteRule ^(application|modules|system) - [F,L]

# Allow any files or directories that exist to be displayed directly
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d

# Rewrite all other URLs to index.php/
RewriteRule .* index.php/$0 [PT,L]

What this will do is take all requests and channel them through the index.php file. So if you visited www.examplesite.com/subjects/php, you may actually be visiting www.examplesite.com/index.php?a=subjects&b=php.

If you find these URLs attractive, I would encourage you to go one step further and check out the MVC Framework (Model, View, Controller). It essentially allows you to treat your website like a group of functions:

www.mysite.com/jokes

public function jokes ($page = 1) {
  # Show Joke Page (Defaults to page 1)
}

Or, www.mysite.com/jokes/2

public function jokes ($page = 1) {
  # Show Page 2 of Jokes (Page 2 because of our different URL)
}

Notice how the first forward slash calls a function, and all that follow fill up the parameters of that function. It's really very nice, and make web-development much more fun!

Answer 2

Keep in mind that redirecting is not the same as rewriting.

A redirect is when the server receives the request and the response is sent as a redirect. For instance, you request a page www.example.com/page. When the server receives this, either the page or the server self issues a redirect command to the browser. The redirect command basically says "go here: new page". In PHP, this is in the form of header('Location: newpage.html');

A rewrite is when the server receives the request from the browser then looks in a list of matching regular expressions for that site. If a match is found, the URL is rewritten into that form and is responded to accordingly. For instance, the requested URL www.example.com/specificpage could be rewritten (on the server end) as www.example.com/?loadpage=specificpage. The browser never receives header information stating that it must go somewhere else.

Answer 3

After reading comments and question once again, I've realized that my previous answer is not completely the thing your are looking for. So here some additions, if you want rewrite/redirect/proxy the URL addresses so for example then user types www.f1.com he will actually see www.f2.com, but domain will remain the same, you probably need to setup a reverse proxy using Apache for that. It act's similar to mod_rewrite.

Regarding the second part, since modern crawler also performing the URL link analyses I think your first option is better performance wise.

Previous answer:
And using PHP you can achieve redirection like:

<?php
// Here you can parse the current location
// and decide whenever you want to go
// if $_SERVER[ 'PHP_SELF'] some conditions then....
header('Location: http://www.example.com/');
?>

From php.net. Here more examples.

Answer 4

Unfortunately, it's really up to the web server, not PHP. Depending on if you use Apache or something else, it has to do this before your script is executed. I use mod_rewrite, and an example rewrite rule looks like this:

<Directory "/home/www/html">
    RewriteEngine On
    RewriteBase /
        RewriteCond %{REQUEST_FILENAME} !-f
        RewriteCond %{REQUEST_FILENAME} !-d
        RewriteRule ^(.*)$ /index.php/%{REQUEST_URI} [PT,L]
</Directory>

The above rule basically says if the URL is a valid path to a real file or directory, load it. Otherwise, run it through index.php.

Answer 5

You cannot do this with PHP alone. You'll need to look into mod_rewrite (assuming you are using apache).

Answer 6

You could approach this slightly differently from the suggestions above by using a Front Controller, it's a common solution for making custom URLs and is used in all languages, not just PHP. Here's a guide: http://www.oreillynet.com/pub/a/php/2004/07/08/front_controller.html

Essentially you would create an index.php file that is called for every URL, its job is to parse the URL and determine which code to run based on the URL's contents. So, for example a user would use a URL such as http://example.com/index.php/videos/play/203/google-io-2009-wave-intro and index.php would extract the remaining elements from the URL (/videos/play/203/google-io-2009-wave-intro) take the first part, load a php file with that name (videos.php or you can make it use play.php) and pass through the parameters 203 and google-io.

It's effectively doing the same thing as rewriting the code in mod_rewrite but does have a few benefits:

1. Doesn't require too much mod_rewrite code if you are new to that.
2. Allows you to put all security code in one place - in index.php
3. It's easy to change URLs and handle 404s etc.

You can remove index.php from the URL using mod_rewrite, see here: http://www.wil-linssen.com/expressionengine-removing-indexphp/