rm -rf /usr/local/etc/bash_completion.d/brew
rm -rf /usr/local/share/zsh/site-functions/_brew
rm -rf /usr/local/share/man/man1/brew.1
rm -rf /usr/local/share/doc/homebrew
brew update



ymdeMacBook-Pro:~ ym$ brew update
Already up-to-date.

brew update          # 更新 Homebrew 的信息
brew outdated        # 看一下哪些软件可以升级
brew upgrade <xxx>   # 如果不是所有的都要升级，那就这样升级指定的

brew upgrade; brew cleanup    # 如果都要升级，直接升级完然后清理干净