php caching

cache.php

https://davidwalsh.name/php-cache-function

/* gets the contents of a file if it exists, otherwise grabs and caches */
function get_content($file,$url,$hours = 24,$fn = '',$fn_args = '') {
	//vars
	$current_time = time(); $expire_time = $hours * 60 * 60; $file_time = filemtime($file);
	//decisions, decisions
	if(file_exists($file) && ($current_time - $expire_time < $file_time)) {
		//echo 'returning from cached file';
		return file_get_contents($file);
	}
	else {
		$content = get_url($url);
		if($fn) { $content = $fn($content,$fn_args); }
		$content.= '<!-- cached:  '.time().'-->';
		file_put_contents($file,$content);
		//echo 'retrieved fresh from '.$url.':: '.$content;
		return $content;
	}
}

/* gets content from a URL via curl */
function get_url($url) {
	$ch = curl_init();
	curl_setopt($ch,CURLOPT_URL,$url);
	curl_setopt($ch,CURLOPT_RETURNTRANSFER,1); 
	curl_setopt($ch,CURLOPT_CONNECTTIMEOUT,5);
	$content = curl_exec($ch);
	curl_close($ch);
	return $content;
}