fetch ip info parallelly, used for analyzing user data

iplookup.php

<?php
//install dependancy: composer require guzzlehttp/guzzle
include 'vendor/autoload.php';
use GuzzleHttp\Client;
use GuzzleHttp\Promise\each_limit;

$client = new Client();
function getIps(){
    while(!feof(STDIN)){
      $ip = trim(fgets(STDIN));
      if($ip !== ''){
        yield $ip;
      }   
    }   
}
$requests = function () use ($client) {
    foreach ( getIps() as $ip) {
        yield $client->getAsync("http://int.dpool.sina.com.cn/iplookup/iplookup.php?ip=$ip")//新浪ip api
            ->then(function ($response) use ($ip) {
                echo "$ip\t" . $response->getBody() . "\n";
            });
    }   
};

$promise = GuzzleHttp\Promise\each_limit(
    $requests(),
    10  
);

$promise->wait();