PHP code to grab and cache Twitter

twitter.php

<?php

function twitter ( $username, $file = 'twitter.xml', $interval = 600 ) {
  
	$url = 'https://api.twitter.com/1/statuses/user_timeline/' . $username . '.xml?count=3';
	if ( ( is_file ( $file ) && ( time () - filemtime ( $file ) ) > $interval ) || filesize ( $file ) == 0 ) {
	
		$curl = curl_init();
		curl_setopt ( $curl, CURLOPT_RETURNTRANSFER, 1 );
		curl_setopt ( $curl, CURLOPT_URL, $url );
		$xml = curl_exec ($curl);
		curl_close ( $curl );
        
		if ( strlen ( $xml ) > 200 ) {
			file_put_contents ( $file, $xml );
		}
		
	} 
	
	if ( filesize ( $file ) > 0 ) {
		return simplexml_load_file ( $file )->status;
	}
	
	return false;
	
}