Screen logger

local oldt=term
local term=setmetatable({},{__index=oldt})
term.old=oldt
local record={}
local tcols={}
local tback={}

local tsym={w=1,o=2,m=4,B=8,y=16,l=32,P=64,g=128,G=256,c=512,p=1024,b=2048,z=4096,r=8192,R=16384,a=32768}

local tC=colors.white
term.setTextColor=function(col)
    tC=col
    return oldt.setTextColor(col)
end
term.setTextColour=function(col)
    tC=col
    return oldt.setTextColour(col)
end

term.getTextColor=function()
    return tC
end

local bC=colors.black
term.setBackgroundColor=function(col)
    bC=col
    return oldt.setBackgroundColor(col)
end
term.setBackgroundColour=function(col)
    bC=col
    return oldt.setBackgroundColour(col)
end

term.getBackgroundColor=function()
    return bC
end

term.write=function(tex)
    local pos={term.getCursorPos()}
    local size={term.getSize()}
    local tS="w"
    local bS="a"
    for k,v in pairs(tsym) do
        if v==term.getTextColor() then tS=k end
        if v==term.getBackgroundColor() then bS=k end
    end
    local function rep(t,txt)
        t[pos[2]+1]=string.sub(t[pos[2]+1] or "",1,pos[1]-1)..(pos[1]>string.len(t[pos[2]+1] or "") and string.rep(" ",pos[1]-string.len(t[pos[2]+1] or "")-1) or "")..txt..string.sub(t[pos[2]+1] or "",pos[1]+#txt)
    end

    rep(record,tex)
    rep(tcols,string.rep(tS,#tex))
    rep(tback,string.rep(bS,#tex))

    for k,v in ipairs(record) do
        if #v>pos[1] then
            record[k+1]=string.sub(v,pos[1]+1)..string.sub(record[k-1],#v+1)
        end
    end
    return oldt.write(tex)
end

term.getTextAt=function(x,y,len)
    if record[y+1] then
        return string.sub(record[y+1],x,x+(len or 1)-1),tsym[string.sub(tcols[y+1],x,x)],tsym[string.sub(tback[y+1],x,x)]
    else
        return nil
    end
end

term.scroll=function(num)
    local tnums={}
    for k,v in pairs(record) do if k>1 then table.insert(tnums,k) end end
    table.sort(tnums)
    for i=1,#tnums do
        record[tnums[i]]=record[tnums[i]+num]
        tcols[tnums[i]]=tcols[tnums[i]+num]
        tback[tnums[i]]=tback[tnums[i]+num]
    end
    return oldt.scroll(num)
end

term.screenShot=function()
    local tNew={{},{},{}}
    for k,v in pairs(record) do
        tNew[1][k]=v
        tNew[2][k]=tcols[k]
        tNew[3][k]=tback[k]
    end
    return unpack(tNew)
end

term.loadScreen=function(t,t2,t3)
    for k,v in pairs(t) do
        term.setCursorPos(1,k)
        for i=1,#v do
            if type(t2)=="table" then
                term.setTextColor(tsym[string.sub(t2[k],i,i)])
            elseif type(t2)=="number" and i==1 then
                term.setTextColor(t2)
            end
            if type(t3)=="table" then
                term.setBackgroundColor(tsym[string.sub(t3[k],i,i)])
            elseif type(t3)=="number" and i==1 then
                term.setTextColor(t3)
            end
            write(string.sub(v,i,i))
        end
    end
end

rawset(getfenv(),"term",term)
rawset(_G,"term",term)
local cur=0
repeat
    cur=cur+1
    local ok,t=pcall(function() return getfenv(cur) end)
    if ok and type(t)=="table" and type(rawget(t,"term"))=="table" then
        rawset(t,"term",term)
    end
until not ok