1. composer 版本更新文档
版本号:https://getcomposer.org/download
中文网:https://docs.phpcomposer.com/03-cli.html#self-update
英文网:https://getcomposer.org/doc/03-cli.md#self-update-selfupdate-
2. 版本更新
查看当前composr版本(大写的V)
composer -V
当前composer更新为最新版
composer self-update
更新到指定版本
composer self-update 1.10.1
3. 版本回滚
回滚到安装的上一个版本
composer self-update -r
或者
composer self-update --rollback
4. 版本更新并删除旧版本的备份
composer self-update --clean-backups