官网：https://brew.sh/index_zh-cn.html
一、旧版安装brew
打开终端输入：/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install.sh)"

二、新版安装brew
新版Xcode没有自带安装Xcode-selected

要先安装对应Xcode的Xcode-selected

1.安装Xcode-selected：Xcode -open develop tools-more develop tools-下载安装Xcode对应版本的command line developer tools
2.安装完
3.打开终端输入：/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install.sh)"