-- from http://computercraft.info/wiki/Redstone_(event)

-- Set up a list which contains the sides as keys, and the current redstone state of each side as a boolean value
statelist = {
  ["top"] = rs.getInput("top"),
  ["front"] = rs.getInput("front"),
  ["left"] = rs.getInput("left"),
  ["right"] = rs.getInput("right"),
  ["back"] = rs.getInput("back"),
  ["bottom"] = rs.getInput("bottom"),
}

-- Ready the terminal for printing to
term.clear()
term.setCursorPos(1,1)

while true do -- Start an endless loop
  os.pullEvent("redstone") -- Yield the computer until some redstone changes
  -- We don't care what the event returns, since the first variable will be "redstone" and the rest will be nil.

  -- Now we check each side to see if it's changed.
  for side, state in pairs(statelist) do -- Run the lines of code in this loop for each key/value pair in statelist
    if rs.getInput(side) ~= state then -- If the side we're checking doesn't match what it was last time we checked then
      print(side.." is now "..tostring(rs.getInput(side))) -- Print the new state of the side.
      statelist[side] = rs.getInput(side) -- Update the statelist with the new change
    end
  end
end