Linux Composer安装，配置国内镜像

• 安装 Composer

wget https://dl.laravel-china.org/composer.phar -O /usr/local/bin/composer
chmod a+x /usr/local/bin/composer

• Composer 镜像加速

• 一、全局配置

composer config -g repo.packagist composer https://packagist.laravel-china.org

• 二、局部配置(仅限当前工程使用镜像，去掉 -g 即可)

composer config repo.packagist composer https://packagist.laravel-china.org

• 全局配置信息(查看[repositories.packagist.org.url]表示当前镜像地址)

composer config -gl

• 取消镜像

composer config -g --unset repos.packagist

• 查看当前版本

composer -v

• 升级 composer 版本

composer selfupdate