Mac OS 10.13.1 以后无法使用telnet命令

Mac OS 10.13.1后删除了telnet命令，telnet是明文密码所以为了安全起见，苹果就取消这个了。
好了我们来解决这个问题：

首先我们直接安装telnet

//在终端输入
brew install telnet

然而我却安装失败了， 提示“No available formula with the name "telnet" ”

C0199BD4-F5A3-4872-8498-88D4CFE2CC79.png

这是没有安装Homebrew造成的

Homebrew — OS X 不可或缺的套件管理器

我们也可以终端输入

/usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"

进行安装，但是安装过程中又出现了问题

196101AF-E2A0-44CD-98BC-9CC4FB1875BE.png

/usr/local/Cellar is not writable. You should change the ownership and permissions of /usr/local/Cellar back to your user account 这时候按照它的的提示做就OK，终端输入

sudo chown -R $(whoami) /usr/local/Cellar

本以为OK了又报错：

7E930F98-621B-4FB9-8BC5-DA7EE5F32DA3.png

Already up-to-date.
Error: Could not link:
/usr/local/share/man/man1/brew.1

Please delete these paths and run `brew update`.
Error: Could not link:
/usr/local/share/doc/homebrew

那我们就终端删除这几个文件：

jiangs:~ liangc$ rm /usr/local/share/man/man1/brew.1
override rw-rw-r--  root/wheel for /usr/local/share/man/man1/brew.1? y
jiangs:~ liangc$ rm -rf /usr/local/share/doc/homebrew

报错Permission denied无权限删除homebrew文件夹，我们来提权

8FDA1E13-E30F-4DAD-BF90-EDFB97FD822C.png

终端输入

sudo chmod -R 777 /usr/local/share/doc/homebrew

然后终端执行

jiangs:homebrew liangc$ rm -rf /usr/local/share/doc/homebrew
jiangs:homebrew liangc$ ruby -e "$(curl -fsSL --insecure https://raw.githubusercontent.com/Homebrew/install/master/install)"

OK成了，我们来安装吧

brew install telnet

爆爆爆爆错啦

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快去更新XCode吧！