Automatic, Apple-style build numbers

Run Script

#!/usr/bin/env ruby

bundle_version_short = %x{/usr/libexec/PlistBuddy -c "Print CFBundleShortVersionString" "$INFOPLIST_FILE"}
bundle_version = %x{/usr/libexec/PlistBuddy -c "Print CFBundleVersion" "$INFOPLIST_FILE"}

build_number  = bundle_version_short.split(".").first
build_number += (bundle_version_short.split(".")[1].to_i + 65).chr
build_number += (bundle_version.scan(/\d+[A-Z](\d+)/).flatten.first.to_i + 1).to_s

%x{/usr/libexec/PlistBuddy -c "Set :CFBundleVersion #{build_number}" "$INFOPLIST_FILE"}