您还可以使用php-curl扩展名设置range标头参数。
$ch = curl_init();curl_setopt($ch, CURLOPT_URL, 'http://www.spiegel.de/');curl_setopt($ch, CURLOPT_RANGE, '0-500');curl_setopt($ch, CURLOPT_BINARYTRANSFER, 1);curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);$result = curl_exec($ch);curl_close($ch);echo $result;
但是如前所述，如果服务器不遵循该标头而是发送整个文件，则curl将下载所有文件。例如，http:
//www.php.net忽略标题。但是，您可以（另外）设置一个写函数回调，并在收到更多数据时中止请求，例如
// php 5.3+ only// use function writefn($ch, $chunk) { ... } for earlier versions$writefn = function($ch, $chunk) { static $data=''; static $limit = 500; // 500 bytes, it's only a test $len = strlen($data) + strlen($chunk); if ($len >= $limit ) { $data .= substr($chunk, 0, $limit-strlen($data)); echo strlen($data) , ' ', $data; return -1; } $data .= $chunk; return strlen($chunk);};$ch = curl_init();curl_setopt($ch, CURLOPT_URL, 'http://www.php.net/');curl_setopt($ch, CURLOPT_RANGE, '0-500');curl_setopt($ch, CURLOPT_BINARYTRANSFER, 1);curl_setopt($ch, CURLOPT_WRITEFUNCTION, $writefn);$result = curl_exec($ch);curl_close($ch);
