Linux安装composer

全局安装composer方法

1. 下载 composer.phar
   curl -sS https://getcomposer.org/installer | php
2. 将composer.phar文件移动到bin目录以便全局使用composer命令
   mv composer.phar /usr/local/bin/composer
3. 切换国内源composer config -g repo.packagist composer https://mirrors.aliyun.com/composer/
4. composer -v  查看版本
5. composer update 更新
6. composer self-update 自我更新
7. composer clear-cache  清除composer 缓存
8. 清理包 composer remove twbs/bootstrap