Need help whit robot movement

[SpaceWolfve 0]

Hello readers, 

 

I need some help whit my code so it can detect if the robot actually moved so it wont mess up its orginal route. I tried some stuff already but im learning lua and i cant figure out how to do this, Thanks!

Mob pusher.txt

[ATastyPeanut 0]

Hi, what's nice is that robot.forward, etc return a value.  Learn more about the function returns on this wiki page http://ocdoc.cil.li/api:robot So all we need to do is check its return value as being true or nil. When it's nil, then it returns a reason why it's failed. In the code below I included two possible reasons it could have failed, and you can add what you want it to do yourself.  Hope it helps you, also try having it either be on pastebin/github or just written in the post details so that we don't need to download sketchy internet files.  Wish I knew how to put the code in the spoiler thing.  :/

local os = require("os")
local component = require("component")
local robot = require("robot")
local computer = require("computer")
local shell = ("shell")

function up(a)
	while a >= 1 do
	local result, possibleError = robot.up()
		if result == true then
			a = a - 1
		else
		print(possibleError)
			if possibleError == "solid"
			
			elseif possibleError == "entity"
		
			else
			
			end
		end
	end
end

function forward(a)
	while a >= 1 do
	local result, possibleError = robot.forward()
		if result == true then
			a = a -1
		else
			print(possibleError)
			if possibleError == "solid"
			
			elseif possibleError == "entity"
		
			else
			
			end
		end
	end
end

function back(a)
	while a >= 1 do
	local result, possibleError = robot.back()
		if result == true then
		a = a - 1
		else
			print(possibleError)
			if possibleError == "solid"
			
			elseif possibleError == "entity"
		
			else
			
			end
		end
	end
end

function down(a)
	while a >= 1 do
	local result, possibleError = robot.down()
		if result == true then
		a = a - 1
		else
			print(possibleError)
			if possibleError == "solid"
			
			elseif possibleError == "entity"
		
			else
			
			end
		end
	end
end

function sleep(a)
	os.sleep(a)
end