composer

sudo su
curl -sS https://getcomposer.org/installer | php
mv composer.phar /usr/local/bin/composer
composer -V

# 127.0.0.1 根目录，创建rr文件夹，进入，执行
composer require noahbuscher/macaw:dev-master

# rr文件夹下 创建index.php

<?php
// Autoload 自动载入
require './vendor/autoload.php';

use NoahBuscherMacawMacaw;

Macaw::get('/rr/index.php', function() {
  echo 'Hello world!';
});

Macaw::dispatch();

# 运行
http://127.0.0.1/rr/index.php

# 127.0.0.1 根目录 执行安装 访问
composer create-project laravel/laravel laravelapp
http://127.0.0.1/laravelapp/public/index.php

/usr/local/php7/bin/php /usr/local/bin/composer create-project codeigniter4/appstarter -s beta

更新  composer update 
指定更新  composer update monolog/monolog