CC: External Shell

os.loadAPI("rnc2")
os.loadAPI("ldb2")

local prg = shell.getRunningProgram()
local label = os.getComputerLabel()
if label == nil then
    return
end

function string.starts(String,Start)
    return string.sub(String,1,string.len(Start))==Start
end

local function isempty(s)
  return s == nil or s == ''
end

function string.split (inputstr, sep)
        if sep == nil then
                sep = "%s"
        end
        local t={}
        for str in string.gmatch(inputstr, "([^"..sep.."]+)") do
                table.insert(t, str)
        end
        return t
end

rnc2.setTimeOut(prg, 99)
rnc2.setPort(prg, 600)
rnc2.setIdenty(prg, 100)

while true do
    rnc2.setIdenty(100)
    local res = rnc2.resive(prg)
    if not isempty(res) and string.starts(res, label .. " ") then
        res = string.sub(res,string.len(label) + 2,string.len(res))
        print("resived message:\"" .. res .. "\"")
        rnc2.setIdenty(prg, 101)
        rnc2.send(prg,label .. "> Command resived!")
        rnc2.setIdenty(prg, 100)

        if not shell.run(res) then
            local temp = string.split(res, " ")
            tempsize = table.getn(temp)
            local inside = ""
            for i = 1, tempsize do
                inside = inside .. '"' .. temp[i] ..'"'
                if i ~= tempsize then
                    inside = inside .. ","
                end
            end
            func = loadstring("shell.run(".. inside ..")")
            setfenv(func, getfenv())
            func()
        end
    end
end
print("magic")