命令
composer下载
查看当前版本
composer --version
升级composer
composer self-update
清空缓存
composer clear-cache
配置阿里云镜像
composer config -g repo.packagist composer https://mirrors.aliyun.com/composer/
composer --version
composer self-update
composer clear-cache
composer config -g repo.packagist composer https://mirrors.aliyun.com/composer/