How to easily Install Autocomplete for Bash on MAC 

By partially typing commands or arguments and then clicking the [Tab] key, you can use the bash completion tool to automatically complete them. You can use this to write the bash command in the terminal.

Installation

brew install bash-completion

Bash completion will be installed in /usr/local/etc/bash_completion.d.

For it to work, add this to your ~/.bash_profile:

[ -f /usr/local/etc/bash_completion ] && . /usr/local/etc/bash_completion

Or simply type:

echo "[ -f /usr/local/etc/bash_completion ] && . /usr/local/etc/bash_completion" >> ~/.bash_profile

To re-read your bash profile: 

source ~/.bash_profile