安装
# php -r "copy('https://install.phpcomposer.com/installer', 'composer-setup.php');"
# php composer-setup.php
All settings correct for using Composer
Downloading...
Composer (version 1.6.5) successfully installed to: /root/composer.phar
Use it: php composer.phar
移动 composer.phar，这样 composer 就可以进行全局调用：
单文件请运行：
composer require 包名
或者
php composer require 包名然后在php文件中引入自动导入
require ‘vendor/autoload.php’;
然后命名空间，例如ipip/db
use itbdw\Ip\IpLocation;