» PHP cURL: Vermeide CURLOPT_RETURNTRANSFER wenn möglich!

$curl = curl_init();
curl_setopt($curl, CURLOPT_URL, 'http://example.com/');
curl_setopt($curl, CURLOPT_HEADER, false);
curl_exec($curl);
curl_close($curl);

$fp = fopen('filename.ext', 'w');
$curl = curl_init();
curl_setopt($curl, CURLOPT_URL, 'http://example.com/');
curl_setopt($curl, CURLOPT_FILE, $fp);
curl_setopt($curl, CURLOPT_HEADER, false);
curl_exec($curl);
curl_close($curl);

// write to variable
$curl = curl_init();
curl_setopt($curl, CURLOPT_URL, 'http://example.com/');
curl_setopt($curl, CURLOPT_HEADER, false);
curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
$result = curl_exec($curl);
curl_close($curl);

// write to variable
$curl = curl_init();
curl_setopt($curl, CURLOPT_URL, 'http://example.com/');
curl_setopt($curl, CURLOPT_HEADER, false);
curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
curl_setopt($curl, CURLOPT_RANGE, '0-51200');
$result = curl_exec($curl);
curl_close($curl);

$result = '';
$limit = 51200;
$curl = curl_init();
curl_setopt($curl, CURLOPT_URL, 'http://example.com/');
curl_setopt($curl, CURLOPT_RANGE, '0-' . $limit);//not all servers support range
curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
curl_setopt($curl, CURLOPT_BINARYTRANSFER, 1);
curl_setopt($curl, CURLOPT_WRITEFUNCTION, function($curl, $chunk) {
	global $result, $limit;
	$len = strlen($result) + strlen($chunk);
	if ($len >= $limit) {
		// if you need corrupt files as well
		//$result .= substr($chunk, 0, $limit - strlen($result));
		// if you need only complete files respecting $limit
		$result = '';
		return -1;
	}
	$result .= $chunk;
	return strlen($chunk);
});
curl_exec($curl);
echo $result;
curl_close($curl);

Mach mit!