新版本的macos 取消了内置的telnet命令，下面介绍一下如何安装：
telnet安装
安装 homebrew
/usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"
这一步，输入密码之后一直回车就可以了
查看homebrew 是否安装成功
shifeiyandeMacBook-Pro:~ shifeiyan$ brew help
Example usage:
brew search [TEXT|/REGEX/]
brew info [FORMULA...]
brew install FORMULA...
brew update
brew upgrade [FORMULA...]
brew uninstall FORMULA...
brew list [FORMULA...]
Troubleshooting:
brew config
brew doctor
brew install --verbose --debug FORMULA
Contributing:
brew create [URL [--no-fetch]]
brew edit [FORMULA...]
Further help:
brew commands
brew help [COMMAND]
man brew
https://docs.brew.sh
shifeiyandeMacBook-Pro:~ shifeiyan$
使用 homebrew 安装telnet
brew install telnet
查看是否安装成功
shifeiyandeMacBook-Pro:~ shifeiyan$ telnet
telnet>
到这一步就安装完成了
telnet使用
shifeiyandeMacBook-Pro:~ shifeiyan$ telnet www.baidu.com 80
Trying 115.239.210.27...
Connected to www.a.shifen.com.
Escape character is '^]'.
之后就可以开心的使用telnet命令了
