[获取远程文件大小] https://blog.cooldev.cn/3042595489.html #remote-filesize #PHP #远程文件大小

getRemoteFileSize.php

<?php

/**
 * 获取远程文件大小
 * @param $url
 * @return int|null
 */
function getRemoteFileSize($url)
{
    $size = null;
    $timeout = 5;
    // 尝试使用HEAD方式请求
    $opts = ['http' => ['method' => 'HEAD', 'header' => ['Connection: close'], 'timeout' => $timeout]];
    $headers = @get_headers($url, 1, stream_context_create($opts));
    // 访问不通直接返回;
    if ($headers === false) return $size;
    // 寻找 Content-Length (绝大多数到这里都会出结果)
    if (isset($headers['Content-Length'])) {
        $cl = $headers['Content-Length'];
        return (int)(is_array($cl) ? array_pop($cl) : $cl);
    }
    // 没有Content-Length,看是否支持提交 Range请求头,寻找 Content-Range
    if (isset($headers['Accept-Ranges']) && $headers['Accept-Ranges'] == 'bytes') {
        $opts = ['http' => ['method' => 'GET', 'header' => ['Range: bytes=0-1', 'Connection: close'], 'timeout' => $timeout]];
        $headers = @get_headers($url, 1, stream_context_create($opts));
        if (isset($headers['Content-Range'])) {
            list(, $size) = explode('/', $headers['Content-Range'], 2);
            return (int)$size;
        }
    }
    // fallback
    // 上面都行不通使用curl,相当于下载但是不写入文件,不会出现file_get_contents的内存超出
    // 但如果远程文件很大,会执行很长时间,通过浏览器请求会触发超时
    $ch = curl_init();
    curl_setopt_array($ch, array(
        CURLOPT_URL => $url,
        CURLOPT_HEADER => false,
        CURLOPT_RETURNTRANSFER => true,
        CURLOPT_FOLLOWLOCATION => true,
        CURLOPT_NOPROGRESS => false
    ));
    curl_setopt($ch, CURLOPT_PROGRESSFUNCTION, function ($curl, $dltotal, $dlnow, $ultotal, $ulnow) use (&$size) {
        $size = $dlnow;
    });
    curl_setopt($ch, CURLOPT_WRITEFUNCTION, function ($curl, $data) {
        return strlen($data);
    });
    curl_exec($ch);
    curl_close($ch);

    return (int)$size;
}