问题：
-bash: telnet: command not found
-bash: brew: command not found
解决：
/usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"
brew install telnet
参考：
brew: command not found
转：https://blog.csdn.net/u012251305/article/details/80499271
