CentOSで壁紙を変更するRubyスクリプト

changewp.rb

#!/usr/local/rbenv/shims/ruby

require "open3"

def gen_export_dbus
  pid = %x[ pgrep -u `whoami` gnome-panel ].chomp
  dbus_address = ""
  File.read("/proc/#{pid}/environ").split("\0").each do |line|
    if /DBUS_SESSION_BUS_ADDRESS/ =~ line
      dbus_address = line.split("=")[1..-1].join("=")
    end
  end

  "export DBUS_SESSION_BUS_ADDRESS=#{dbus_address}"
end

def get_datetime
  Time.now.strftime("%Y-%m-%d %H:%M:%S")
end

def exec_cmd(cmd)
  so, se, sts = Open3.capture3(cmd)
  puts "#{get_datetime} [OUTPUT] : #{so}" if so != ""
  puts "#{get_datetime} [ERROR]  : #{se}" if se != ""
  puts "#{get_datetime} [STATUS] : #{sts}" if sts != ""
end

def select_wallpaper
  current = `gconftool-2 --get '/desktop/gnome/background/picture_filename'`
  puts "#{get_datetime} : Current picture is #{current}"
  pics = Array.new()
  nextpic = ""
  Dir.glob("#{ENV['HOME']}/wallpapers/*").each do |f|
    pics << f if f != current
  end
  pics.sample
end

exd = gen_export_dbus
wallpaper = select_wallpaper
exec_cmd("#{exd}; gconftool-2 --type string --set '/desktop/gnome/background/picture_options' scaled")
exec_cmd("#{exd}; gconftool-2 --type string --set '/desktop/gnome/background/picture_filename' #{wallpaper}")
puts "#{get_datetime} : Changed to #{wallpaper}"