brewed-bash.sh

#!/usr/bin/env bash

# Install command-line tools using Homebrew.

# Ask for the administrator password upfront.
sudo -v

# Keep-alive: update existing `sudo` time stamp until the script has finished.
while true; do sudo -n true; sleep 60; kill -0 "$$" || exit; done 2>/dev/null &

# Install Homebrew.
if [[ ! "$(type -P brew)" ]]; then
  true | ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"
fi

# Exit if, for some reason, Homebrew is not installed.
[[ ! "$(type -P brew)" ]] && e_error "Homebrew failed to install." && return 1

brew tap homebrew/versions
brew install bash

# Switch to using brew-installed bash as default shell
if ! fgrep -q "$(brew --prefix)/bin/bash" /etc/shells; then
  echo "$(brew --prefix)/bin/bash" | sudo tee -a /etc/shells;
  chsh -s $(brew --prefix)/bin/bash;
fi;

# Remove outdated versions from the cellar.
brew cleanup