brew-cask-upgrade

#!/bin/bash

# Script to upgrade all Homebrew Cask packages and cleanup old versions

baseDir="/usr/local/Caskroom"
metadataDir=".metadata"

# Loop over all installed casks
for package in `brew cask list`; do

    # Get latest version of cask
    packageVersionSearch="$package: "
    packageVersionLine=`brew cask info $package | grep $packageVersionSearch`
    packageVersion=${packageVersionLine#$packageVersionSearch}

    # If latest version is not installed then install it
    cd "$baseDir/$package"
    if [ ! -d "$packageVersion" ]; then
        brew cask install --force "$package"
    fi

    # Remove old version folders and files from the cask directory
    for folder in */; do
        if [ "$folder" != "$packageVersion/" ]; then
            rm -rf "$folder"
        fi
    done

    # Remove old version folders and files from the cask metadata directory
    cd "$baseDir/$package/$metadataDir"
    for folder in */; do
        if [ "$folder" != "$packageVersion/" ]; then
            rm -rf "$folder"
        fi
    done
done