script to show battery charge in your terminal

charge

#!/usr/bin/env ruby
class Charge
  attr_reader :state, :status
  def initialize
    @state, @status = `pmset -g batt`.split("\n")
  end

  def time_remaining
    @time_remaining ||= begin
      amount = status.match(/(\d+:\d+)/)[1]
      amount.nil? ? '0:00' : amount
    end
  end

  def percent_remaining
    @percent_remaining ||= begin
      amount = status.match(/Battery\-0\t(.*)%;/)[1]
      amount.nil? ? 0 : amount.to_i
    end
  end

  def charging?
    state.match(/AC Power/)
  end

  def prompt
    "#{color}#{character}%{%}"
  end

  private

  def character
    percent_remaining == 0 ? '?' : '›'
  end

  def to_s
    [@state, @status].join("\n")
  end

  def color
    case
    when charging?
      '%{%}'   # green
    when percent_remaining <= 25
      '%{%}'   # red
    when percent_remaining <= 50
      '%{%}' # yellow
    else
      '%{%}' # white
    end
  end
end

charge = Charge.new
puts case ARGV[0]
when '--prompt'
  charge.prompt
else
  charge
end