function getContentLength($strURL)
{
???$resURL = curl_init();
???curl_setopt($resURL, CURLOPT_URL, $strURL);
???curl_setopt($resURL, CURLOPT_PROGRESSFUNCTION, ‘progressCallback‘);
???curl_setopt($resURL, CURLOPT_NOPROGRESS, false);
???curl_setopt($resURL, CURLOPT_RETURNTRANSFER, true);
???$res = curl_exec ($resURL);
???curl_close ($resURL);
}
function progressCallback($resource, $download_size = 0, $downloaded = 0, $upload_size = 0, $uploaded = 0)
{
???global $lens;
???if ($download_size > 0) {
???????$res = curl_getinfo($resource);
???????$url = $res[‘url‘];
???????$pkg = strstr($url,‘?id=‘);
???????$pkg = str_replace(‘?id=‘,‘‘,$pkg);
???????$lens[$pkg] = $download_size;
???????return $res;
???}
}
php 异步获取文件下载文件大小（不用下载）
原文地址：https://www.cnblogs.com/leescre/p/8778384.html