Ruby script to pipe `pmset` for battery info and display status back in readable text. Created for display in tmux status bar.

tmuxBattery.rb

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

status = Hash.new()

if ARGF === nil
  puts "NA"
  exit
end

ARGF.each do |arg|
  if arg.start_with? "Now drawing"
    if arg.include? "AC Power"
      status[:source] = "AC"

    elsif arg.include? "Battery Power"
      status[:source] = "battery"

    else
      status[:source] = "Uh oh..."

    end
  elsif arg.start_with? " -InternalBattery"
    split = arg.match(/(\d{1,3})%;\s(.*);\s(\d:\d{2}|\(no estimate\))/)

    status[:amount] = split[1]
    status[:charged] = split[2] === "charged" ? true : false
    status[:remaining] = split[3]
  end
end

output = "Running on #{status[:source]} with "

if status[:charged]
  output += "a full charge"
else
  output += "#{status[:amount]}% left and #{status[:remaining]} until "
end

if status[:source] === "battery"
  output += "empty"
elsif status[:source] === "battery" && !status[:charged]
  output += "full"
end

puts output