View difference between Paste ID: KJBKSZG8 and pK6gs0Nb

 local tArgs = { ... }
 if #tArgs ~= 1 then
 	print( "Usage: tunnel <length>" )
 	return
 end
 
 -- Mine in a quarry pattern until we hit something we can't dig
 local length = tonumber( tArgs[1] )
 if length < 1 then
 	print( "Tunnel length must be positive" )
 	return
 end
 
 local depth = 0
 local collected = 0
 
 local function collect()
 	collected = collected + 1
 	if math.fmod(collected, 25) == 0 then
 		print( "Mined "..collected.." items." )
 	end
 end
 
 local function tryDig()
 	while turtle.detect() do
 		if turtle.dig() then
 			collect()
 			sleep(0.5)
 		else
 			return false
 		end
 	end
 	return true
 end
 
 local function tryDigUp()
 	while turtle.detectUp() do
 		if turtle.digUp() then
 			collect()
 			sleep(0.5)
 		else
 			return false
 		end
 	end
 	return true
 end
 
 local function tryDigDown()
 	while turtle.detectDown() do
 		if turtle.digDown() then
 			collect()
 			sleep(0.5)
 		else
 			return false
 		end
 	end
 	return true
 end
 
 local function refuel()
 	local fuelLevel = turtle.getFuelLevel()
 	if fuelLevel == "unlimited" or fuelLevel > 0 then
 		return
 	end
 
 	local function tryRefuel()
 		for n=1,16 do
 			if turtle.getItemCount(n) > 0 then
 				turtle.select(n)
 				if turtle.refuel(1) then
 					turtle.select(1)
 					return true
 				end
 			end
 		end
 		turtle.select(1)
 		return false
 	end
 
 	if not tryRefuel() then
 		print( "Add more fuel to continue." )
 		while not tryRefuel() do
 			os.pullEvent( "turtle_inventory" )
 		end
 		print( "Resuming Tunnel." )
 	end
 end
 
 local function tryUp()
 	refuel()
 	while not turtle.up() do
 		if turtle.detectUp() then
 			if not tryDigUp() then
 				return false
 			end
 		elseif turtle.attackUp() then
 			collect()
 		else
 			sleep( 0.5 )
 		end
 	end
 	return true
 end
 
 local function tryDown()
 	refuel()
 	while not turtle.down() do
 		if turtle.detectDown() then
 			if not tryDigDown() then
 				return false
 			end
 		elseif turtle.attackDown() then
 			collect()
 		else
 			sleep( 0.5 )
 		end
 	end
 	return true
 end
 
 local function tryForward()
 	refuel()
 	while not turtle.forward() do
 		if turtle.detect() then
 			if not tryDig() then
 				return false
 			end
 		elseif turtle.attack() then
 			collect()
 		else
 			sleep( 0.5 )
 		end
 	end
 	return true
 end
 
 print( "Tunnelling..." )
 
 for n=1,length do
 	turtle.placeDown()
 	tryDigUp()
 	turtle.turnLeft()
 	tryDig()
 	tryUp()
 	tryDig()
 	turtle.turnRight()
 	turtle.turnRight()
 	tryDig()
 	tryDown()
 	tryDig()
 	turtle.turnLeft()
 
 	if n<length then
 		tryDig()
 		if not tryForward() then
 			print( "Aborting Tunnel." )
 			break
 		end
 	else
 		print( "Tunnel complete." )
 	end
 
 end
 
 --[[
 print( "Returning to start..." )
 
 -- Return to where we started
 turtle.turnLeft()
 turtle.turnLeft()
 while depth > 0 do
 	if turtle.forward() then
 		depth = depth - 1
 	else
 		turtle.dig()
 	end
 end
 turtle.turnRight()
 turtle.turnRight()
 ]]
 
 print( "Tunnel complete." )
 print( "Mined "..collected.." items total." )