实用工具：PHP 异步 HTTP 下载多个文件的开发工具推荐

<?php

require 'vendor/autoload.php';

$urls = [
    'http://example.com/file1.txt',
    'http://example.com/file2.txt',
    'http://example.com/file3.txt',
];

$httpClient = new GuzzleHttpClient();

$promises = [];

foreach ($urls as $url) {
    $promises[] = $httpClient->getAsync($url);
}

$results = GuzzleHttpPromisell($promises)->wait();

foreach ($results as $response) {
    // 处理下载的文件数据
    $data = $response->getBody()->getContents();
    // ...
}

<?php

require 'vendor/autoload.php';

$urls = [
    'http://example.com/file1.txt',
    'http://example.com/file2.txt',
    'http://example.com/file3.txt',
];

$loop = ReactEventLoopFactory::create();
$httpClient = new ReactHttpClientClient($loop);

$requests = [];

foreach ($urls as $url) {
    $request = $httpClient->request('GET', $url);
    $requests[$url] = '';

    $request->on('response', function (ReactHttpClientResponse $response) use ($url, &$requests) {
        $response->on('data', function ($data) use ($url, &$requests) {
            $requests[$url] .= $data;
        });

        $response->on('end', function () use ($url, &$requests) {
            // 处理下载的文件数据
            $data = $requests[$url];
            // ...

            unset($requests[$url]);
        });
    });

    $request->end();
}

$loop->run();