top level edit

local function max(tPar)
    local count
    for k,v in pairs(tPar) do
        if (tonumber(k) or 0)>(tonumber(count) or 0) then count=k end
    end
    return count
end

local messages=function()
    local timer
    local len
    local function clear()
        if len then
            local size={term.getSize()}
            local pos={term.getCursorPos()}
            term.setCursorPos(size[1]-len,1)
            write(string.rep(" ",len))
            len=nil
            timer=nil
            term.setCursorPos(unpack(pos))
        end
    end
    while true do
        local evts={os.pullEventRaw()}
        if evts[1]=="message" and type(evts[2]=="string") then
            clear()
            local size={term.getSize()}
            local pos={term.getCursorPos()}
            term.setCursorPos(size[1]-#evts[2],1)
            write(evts[2])
            term.setCursorPos(unpack(pos))
            timer=os.startTimer(2)
            len=#evts[2]
        elseif evts[1]=="timer" and timer==evts[2] then
            clear()
        end
    end
end

local tO={}
local tCo={coroutine.create(function() os.run({},"rom/programs/shell") end),coroutine.create(messages)}
local pE=printError
local current=0
local pE2=function(...)
    term.clear()
    term.setCursorPos(1,1)
    for k,v in pairs(tO) do
        rawset(k,"printError",pE)
    end

    for k,v in pairs(fs.list("rom/apis")) do
        if type(_G[v])=="table" and v~="term" then
            os.unloadAPI(v)
            os.loadAPI("rom/apis/"..v)
        end
    end
    tCo[3]=coroutine.create(rednet.run)

    local tEvts={}
    while true do
        local tDone={}
        for k,v in pairs(tCo) do
            current=k
            if coroutine.status(v)=="dead" then
                table.insert(tDone,k)
                os.queueEvent("message","coroutine "..k.." has died")
            else
                pcall(coroutine.resume(v,unpack(tEvts)))
            end
        end
        for k,v in pairs(tDone) do
            tCo[v]=nil
        end
        if #tCo==0 then
            break
        end
        os.startTimer(1)
        tEvts={os.pullEventRaw()}
    end
    print("all coroutines have been terminated, ending now")
    sleep(2)
end

for i=1,5 do
    if rawget(getfenv(i),"printError")~=nil and not tO[getfenv(i)] then
        tO[getfenv(i)]=true
        rawset(getfenv(i),"printError",pE2)
    end
end

rawset(_G,"addCo",function(func,ref)
    local t=type(func)
    if not t=="function" then
        print("incorrect param #1 function expected, got "..t)
        return nil, ("incorrect param #1 function expected, got "..t)
    end
    tCo[ref or max(tCo)+1]=coroutine.create(func)
    return ref or max(tCo)
end)

rawset(_G,"remCo",function(num,b)
    num=num or 0
    if not tCo[num] then
        print("There is no coroutine under that reference")
        return nil
    elseif num==current then
        print("cannot remove the current coroutine")
        return nil
    end
    tCo[num]=nil
    if b then
        os.queueEvent("message","coroutine "..num.." has died")
    end
    return true
end)

os.queueEvent("terminate")