lua computer 2x2 transformer door

-- pastebin get Bq3kqiSa startup
-- -------------------------------------------
-- 2x2 transformer door -Sinkir-
-- Version 1
-- setup :
-- Computer with 3 repater on 3 side
-- and restone signal in front.
-- 3 input rednet cable (3 colors)
-- view from top
-- r r r
-- r R r
-- rRCRr
--   I
-- r = rednet cable
-- R = repeater
-- C = Computer
-- I = Input (redstone)
-- -------------------------------------------
--
--    P
--   S S
--   ob oS
--  S OOb P
-- P bOO S
--  So bo
--    S S
--     P
-- 2x2 door
-- S = Sticky piston
-- P = Piston
-- O = block of the door 1
-- o = block of the door 2
-- b = block of deco (like your walls)
-- " " space are air block

function split(str, pat)
    -- source of the function :
    -- http://lua-users.org/wiki/SplitJoin
    -- Compatibility: Lua-5.1
    local t = {}  -- NOTE: use {n = 0} in Lua-5.0
    local fpat = "(.-)" .. pat
    local last_end = 1
    local s, e, cap = str:find(fpat, 1)
    while s do
        if s ~= 1 or cap ~= "" then
            table.insert(t,cap)
        end
        last_end = e+1
        s, e, cap = str:find(fpat, last_end)
    end
    if last_end <= #str then
        cap = str:sub(last_end)
        table.insert(t, cap)
    end
    return t
end
function fileGet(path)
        if(fs.exists(path))then
                tabFile = fs.open(path, "r")
                text = tabFile.readAll()
                tabFile.close()
                return text
        else
                print("fileGet() File not found.")
                print(path)
                return false
        end
end

function fileSet(path, text)
        if(fs.isReadOnly(path))then
                print("fileSet() File is read only.")
                print(path)
                return false
        else
                tabFile = fs.open(path, "w")
                tabFile.write(text)
                tabFile.close()
                return true
        end
end

function savedata()
    fileSet("data", a ..",".. b)
end

function dealer()
    redstone.setOutput("back", true)
    sleep(0.1)
    redstone.setOutput("back", false)
end

function swaper()
    redstone.setOutput("left", true)
    sleep(0.1)
    redstone.setOutput("left", false)
end
function pusher()
    redstone.setOutput("right", true)
    sleep(0.1)
    redstone.setOutput("right", false)
end


if(fs.exists("data")==true)then
    --Shaundi()
else
    fileSet("data", "0,0")
end
tab = split(fileGet("data"), ",")
a = tostring(tab[1])
b = tostring(tab[2])
flag = false
while(2)do
    if(redstone.getInput("front") == true and flag == false)then
        --
        if(a == "0")then
            dealer()
            a = "1"
        elseif(a == "1")then
            if(b == "0")then
                dealer()
                sleep(0.1)
                swaper()
                sleep(0.1)
                dealer()
                sleep(0.1)
                dealer()
                sleep(0.1)

                b = "1"
            elseif(b == "1")then
                pusher()
                sleep(0.1)
                dealer()
                sleep(0.1)
                dealer()
                sleep(0.1)

                b = "2"
            elseif(b == "2")then
                pusher()
                sleep(0.1)
                swaper()
                sleep(0.1)

                b = "0"
            end
            a = "0"
        end
        savedata()


        flag = true
    end
    if(redstone.getInput("front") == false)then
        flag = false
    end
    sleep(0.2)
end