code website in php with sef url's

How can I make the custom core php code website to show sef url. I mean to say how the coding technique should be altered in-order to make the site to have sef URL's.

I will elaborate...

suppose my php calls only the index.php file with some parameters to redirect to the page

/index.php?tas开发者_高级运维k=show_page2

I want this to make

/page2

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Use Apache's mod_rewrite module. It allows you to specify rules which map arbitrary request URIs to the real files and parameters you want to handle them.

For example, in a .htaccess file or Apache's httpd.conf:

RewriteEngine On
RewriteRule page2 index.php?task=show_page2 [L]

You do not have to change any of your PHP code as this happens at the web server level, before PHP is invoked.