Install Bash Completion for Mac OS-X

One of the nicest features of the modern shell is built in “completion” support. This allows you to complete commands and their arguments easily without memorizing.

Unfortunately, Mac OS-X bash shell doesn’t have completion feature by default unlike Ubuntu(Debian based Linux OS).
But the good thing is you can easily install the auto-completion by using Homebrew or Macports.

Homebrew is my favorite packaging tool for OS-X, I will be explaining the installation using this tool.

Bash Completion Installation

1. Install bash-completion package using brew

brew install bash-completion

2. Edit the ~/.bash_profile

vi ~/.bash_profile

And add the following code:

if [ -f $(brew --prefix)/etc/bash_completion ]; then
    . $(brew --prefix)/etc/bash_completion
fi

3. Reload the bash shell

source ~/.bash_profile

Now try to type few letters of command and press [TAB], you will see the auto-completed command or auto-suggested commands(for more than one matches). For example:
nets[TAB] ->

netstat

net[TAB] ->

net-server               net-server5.18           net-snmp-config
net-server5.16           net-snmp-cert            net-snmp-create-v3-user

Bonus

You can also install additional completions from Homebrew-Completions
All you have to do is:

brew tap homebrew/completions
brew install <formula>

If you know how to create bash completions, you can create your own file and drop in the folder:

/usr/local/etc/bash_completion.d

After sourcing(loading), your custom completion is ready to take into account.

Please do share/comment on your favorite bash-completion.