Mac安装brew

1.安装命令

curl -LsSf http://github.com/mxcl/homebrew/tarball/master | sudo tar xvz -C/usr/local --strip 1

2.更新brew：brew update

出现错误提示：/usr/local must be writable!

解决：给电脑用户加权限

https://www.jianshu.com/p/36250f81e28b

3.重新update时报错

（1）Error: Could not link:

        /usr/local/share/doc/homebrew

        Please delete these paths and run `brew update`.

        删除rm -r -f /usr/local/share/doc/homebrew

4.检查是否正常：brew doctor

正常：Your system is ready to brew.