strip mine

function drop() -- drops all stuff into inventory
turtle.select(1)
turtle.drop()
turtle.select(2)
turtle.drop()
turtle.select(3)
turtle.drop()
turtle.select(4)
turtle.drop()
turtle.select(5)
turtle.drop()
turtle.select(6)
turtle.drop()
turtle.select(7)
turtle.drop()
turtle.select(8)
turtle.drop()
turtle.select(9)
turtle.drop()
turtle.select(10)
turtle.drop()
turtle.select(11)
turtle.drop()
turtle.select(12)
turtle.drop()
turtle.select(13)
turtle.drop()
turtle.select(14)
turtle.drop()
turtle.select(15)
turtle.drop()
turtle.select(16)
turtle.drop()
end


function backL()  --goes back when turtle is facing left and empties inventory
turtle.turnLeft()
turtle.forward()
if z ~= 1
	then
		for g=1, z-1
			do turtle.down()
		end
end
for i=1 , y-1
	do
		if turtle.forward()
		then turtle.forward()
		else
			turtle.attack()
			sleep(.2)
			turtle.forward()
		end
end
drop()
sleep(.1)
if z~=1
	then
		for g=1, z-1
			do turtle.up()
		end
end
turtle.turnRight()
turtle.turnRight()
for i=1 , y
	do
		if turtle.forward()
		then turtle.forward()
		else
			turtle.attack()
			sleep(.2)
			turtle.forward()
		end
end
turtle.turnLeft()
end


function backR()  --goes back when turtle is facing right and empties inventory
turtle.turnRight()
turtle.forward()
if z ~= 1
	then
		for g=1, z-1
			do turtle.down()
		end
end
for i=1 , y-1
	do
		if turtle.forward()
		then turtle.forward()
		else
			turtle.attack()
			sleep(.2)
			turtle.forward()
		end
end
drop()
sleep(.1)
if z~=1
	then
		for g=1, z-1
			do turtle.up()
		end
end
turtle.turnRight()
turtle.turnRight()
for i=1 , y
	do
		if turtle.forward()
		then turtle.forward()
		else
			turtle.attack()
			sleep(.2)
			turtle.forward()
		end
end
turtle.turnRight()
end


function back()  --goes back when turtle is facing forward and empties inventory
turtle.turnRight()
turtle.turnRight()
turtle.forward()
if z ~= 1
	then
		for g=1, z-1
			do turtle.down()
		end
end
for i=1 , y-1
	do
		if turtle.forward()
		then turtle.forward()
		else
			turtle.attack()
			sleep(.2)
			turtle.forward()
		end
end
drop()
sleep(.1)
if z~=1
	then
		for g=1, z-1
			do turtle.up()
		end
end
turtle.turnRight()
turtle.turnRight()
for i=1 , y
	do
		if turtle.forward()
		then turtle.forward()
		else
			turtle.attack()
			sleep(.2)
			turtle.forward()
		end
end
end


function dig()  --this is to protect against gravel and sand
while turtle.dig()
	do
		turtle.dig()
		sleep(.2)
end
end


function digup()  --this is to protect against gravel and sand above
while turtle.digUp()
	do
		turtle.digUp()
		sleep(.3)
end
end


function checkbackL()  --this will check inventory and if it is full will go back
if
turtle.getItemCount(1)>0
and
turtle.getItemCount(2)>0
and
turtle.getItemCount(3)>0
and
turtle.getItemCount(4)>0
and
turtle.getItemCount(5)>0
and
turtle.getItemCount(6)>0
and
turtle.getItemCount(7)>0
and
turtle.getItemCount(8)>0
and
turtle.getItemCount(9)>0
and
turtle.getItemCount(10)>0
and
turtle.getItemCount(11)>0
and
turtle.getItemCount(12)>0
and
turtle.getItemCount(13)>0
and
turtle.getItemCount(14)>0
and
turtle.getItemCount(15)>0
and
turtle.getItemCount(16)>0
	then backL()
end
end


function checkbackR()
if
turtle.getItemCount(1)>0
and
turtle.getItemCount(2)>0
and
turtle.getItemCount(3)>0
and
turtle.getItemCount(4)>0
and
turtle.getItemCount(5)>0
and
turtle.getItemCount(6)>0
and
turtle.getItemCount(7)>0
and
turtle.getItemCount(8)>0
and
turtle.getItemCount(9)>0
and
turtle.getItemCount(10)>0
and
turtle.getItemCount(11)>0
and
turtle.getItemCount(12)>0
and
turtle.getItemCount(13)>0
and
turtle.getItemCount(14)>0
and
turtle.getItemCount(15)>0
and
turtle.getItemCount(16)>0
	then backR()
end
end


function checkback()
if
turtle.getItemCount(1)>0
and
turtle.getItemCount(2)>0
and
turtle.getItemCount(3)>0
and
turtle.getItemCount(4)>0
and
turtle.getItemCount(5)>0
and
turtle.getItemCount(6)>0
and
turtle.getItemCount(7)>0
and
turtle.getItemCount(8)>0
and
turtle.getItemCount(9)>0
and
turtle.getItemCount(10)>0
and
turtle.getItemCount(11)>0
and
turtle.getItemCount(12)>0
and
turtle.getItemCount(13)>0
and
turtle.getItemCount(14)>0
and
turtle.getItemCount(15)>0
and
turtle.getItemCount(16)>0
	then back()
end
end


--main body use check() to set n to true or false then use "" to make sure progam knows what it is
print("How long of a tunnel do you want? (must be a multiple of 2)")
y=1
x=read()
for i=1, x/2
   do
	z=1
	dig()
	checkback()
	sleep(0.1)
	turtle.forward()
	y=y+1
        sleep(.1)
        turtle.turnRight()
        sleep(.1)
        dig()
	checkbackR()
        sleep(.1)
        turtle.turnLeft()
        turtle.turnLeft()
        sleep(.1)
        dig()
	checkbackL()
        sleep(.1)
        digup()
	checkbackL()
        sleep(.1)
        turtle.up()
	z=2
        sleep(.1)
        dig()
	checkbackL()
        sleep(.1)
        turtle.turnRight()
        turtle.turnRight()
        sleep(.1)
        dig()
	checkbackR()
        sleep(.1)
        digup()
	checkbackR()
        sleep(.1)
        turtle.up()
	z=3
        sleep(.1)
        dig()
	checkbackR()
        sleep(.1)
        turtle.turnLeft()
        turtle.turnLeft()
        sleep(.1)
        dig()
	checkbackL()
        sleep(.1)
        turtle.turnRight()
        sleep(.1)
        dig()
	checkback()
        sleep(.1)
        turtle.forward()
	y=y+1
        sleep(.1)
        turtle.turnRight()
        sleep(.1)
        dig()
	checkbackR()
        turtle.turnLeft()
        turtle.turnLeft()
        sleep(.1)
        dig()
	checkbackL()
        sleep(.1)
        turtle.digDown()
	checkbackL()
        sleep(.1)
        turtle.down()
	z=2
        sleep(.1)
        dig()
	checkbackL()
        sleep(.1)
        turtle.turnRight()
        turtle.turnRight()
        sleep(.1)
        dig()
	checkbackR()
        sleep(.1)
        turtle.digDown()
	checkbackR()
        sleep(.1)
        turtle.down()
	z=1
        sleep(.1)
        dig()
	checkbackR()
        sleep(.1)
        turtle.turnLeft()
        turtle.turnLeft()
        sleep(.1)
        dig()
	checkbackL()
        sleep(.1)
        turtle.turnRight()
end

turtle.turnRight()
turtle.turnRight()
for i=1 , y
	do
		if turtle.forward()
		then turtle.forward()
		else
			turtle.attack()
			sleep(.2)
			turtle.forward()
		end
end
drop()