.htaccess

Options -Indexes
Options +FollowSymlinks
RewriteEngine on
#index is /

RewriteRule ^articles.html$ articles.php
RewriteRule ^articles/page-([0-9]{1,}).html$ articles.php?p=$1
RewriteRule ^articles/([a-zA-Z0-9-]{2,})/page-([0-9]{1,}).html$ articles.php?p=$2&cat=$1
RewriteRule ^articles/([a-zA-Z0-9-]{2,}).html$ articles.php?cat=$1

RewriteRule ^article-[a-zA-Z0-9-]{1,}-([0-9]{1,}).html$ article.php?id=$1

RewriteRule ^session.html$ session.php
RewriteRule ^cart.html$ cart.php
RewriteRule ^transaction.html$ transaction.php
RewriteRule ^sale.html$ sale.php

RewriteRule ^action/add.html/id=([0-9]{1,})$ action.php?a=a&id=$1
RewriteRule ^action/buy.html/id=([0-9]{1,})$ action.php?a=b&id=$1
RewriteRule ^action/delete.html/id=([0-9]{1,})$ action.php?a=r&id=$1