function getFile($url, $save_dir = '', $filename = '', $type = 0) {

if (trim($url) == '') {

return false;

}

if (trim($save_dir) == '') {

$save_dir = './';

}

if (0 !== strrpos($save_dir, '/')) {

$save_dir.= '/';

}

//创建保存目录

if (!file_exists($save_dir) && !mkdir($save_dir, 0777, true)) {

return false;

}

//获取远程文件所采用的方法

if ($type) {

$ch = curl_init();

$timeout = 5;

curl_setopt($ch, CURLOPT_URL, $url);

curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);

curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, $timeout);

$content = curl_exec($ch);

curl_close($ch);

} else {

ob_start();

readfile($url);

$content = ob_get_contents();

ob_end_clean();

}

$size = strlen($content);

//文件大小

$fp2 = @fopen($save_dir . $filename, 'a');

fwrite($fp2, $content);

fclose($fp2);

unset($content, $url);

return true;

}

$url = '下载文件的路径url';

$save_dir ="保存的文件路径";

$filename="文件名.zip";

getFile（$url,$save_dir,$filename）