Ruby Mac Battery Display

battery.rb

#!/usr/bin/ruby
# encoding: utf-8

# Mac OS X Battery Display
#
# ▐▐▐▐▐▐▐▐▐▐
#
# by Nathan Lilienthal <nathanl@ccs.neu.edu> 2012
# Distributed under the GNU General Public License, version 3.0.
#
#
# Running this command will output a 10 segmented bar indicating
# the computer's current battery state, and if it's plugged in.
#

WIDTH = 10
LIT_RED_BLOCK    = "\e[31m▐\e[0m"
LIT_YELLOW_BLOCK = "\e[33m▐\e[0m"
LIT_GREEN_BLOCK  = "\e[32m▐\e[0m"
UNCHARGED_BLOCK  = "\e[2m\e[37m▐\e[0m"

def battery
  hash = { }
  data = IO.popen("ioreg -rc AppleSmartBattery").readlines()
  data.select { |l| l =~ /=/ }.map{ |l| l.strip.gsub("\"", "") }.each do |l|
    key, value   = l.split " = "
    hash[key] = value
  end
  return hash
end

def block( i, dim )
  if i / WIDTH.to_f >= 3.0/5.0
    b = LIT_GREEN_BLOCK
  elsif i / WIDTH.to_f >= 1.0/5.0
    b = LIT_YELLOW_BLOCK
  else
    b = LIT_RED_BLOCK
  end

  # append dimming escape
  b = "\e[2m" + b if dim
  return b
end

def bar( charge, charging )
  b = ""
  WIDTH.times do |i|
    if (charge / 100 * WIDTH).round >= i
      b += block(i, false)
    else
      b += charging ? block(i, true) : UNCHARGED_BLOCK
    end
  end
  "#{b}\n"
end

# Current charge of computer (%)
charge = 100 * (battery['CurrentCapacity'].to_f / battery['MaxCapacity'].to_f)

# Print this bitch
print bar(charge, battery['IsCharging'] == "Yes")

Want to add this to zsh's RPROMPT? Easy.

RPROMPT='%10{$(echo `battery`)%}'