Mac切换zsh

$ which zsh
# /usr/bin/zsh 说明是系统自带zsh
$ brew install zsh
# 安装zsh...
$ which zsh
# /usr/local/bin/zsh 可以看到软连接是brew安装的zsh
$ sudo vi /etc/shells
# 把 /usr/local/bin/zsh 写入文件
$ chsh -s /usr/local/bin/zsh
$ which zsh
# /usr/local/bin/zsh
$ echo $SHELL
# /usr/local/bin/zsh
$ zsh --version
# 查看zsh版本