composer
查看当前版本
composer --version or composer -v更新版本（慎用）
composer selfupdate 或者 composer self-update回退composer 版本
composer self-update --rollback清理缓存
composer clearcache查看Composer配置中的镜像地址：
composer config -gl修改镜像地址为中国镜像：
composer config -g repo.packagist composer Packagist / Composer其它镜像
#阿里云
composer config -g repo.packagist composer https://mirrors.aliyun.com/composer/
#腾讯云
composer config -g repo.packagist composer PHP Composer
如果在gitm命令里面别git-bash 不识别 composer.bat 文件，就把composer.phar文件复制了一份，重命名为composer（正常是对应的php版本目录里面）
