How can PHP developers effectively handle domain redirections and directory structures in .htaccess files to ensure seamless functionality across multiple URLs?

When dealing with domain redirections and directory structures in .htaccess files for PHP applications, developers can use RewriteRule directives to easily manage the routing of URLs. By specifying the desired redirection rules and directory structures in the .htaccess file, developers can ensure that requests are properly redirected and handled across multiple URLs. ```apache RewriteEngine On # Redirect all requests to index.php for processing RewriteCond %{REQUEST_FILENAME} !-f RewriteCond %{REQUEST_FILENAME} !-d RewriteRule ^(.*)$ index.php?url=$1 [L] ```