local tArgs = {...} -- Get the commandline arguments
local sExpr = table.concat(tArgs, " ")  -- Concatenate the args back to <arg1> <arg2> <arg..>
local fnMath, sErr = loadstring("return "..sExpr)   -- Load the expression provided via commandline arguments into a function block

if not fnMath then  -- If fnMath is nil we failed to load the function, print the error returned
    print("ERROR: "..sErr)
    return
end
--[[
    Given sExpr = "5+9/8*(98 - 45)"
    The above loadstring is equivalent to
    fnMath = function()
        return 5+9/8*(98 - 45)
    end
--]]

setfenv(fnMath, math) -- Set the functions environment 'root' in the math table instead of _G
--[[
    This allows for an expression like:  8 * 6 / sin(rad(36))
    But it also allows for expressions like:  _G.os.shutdown()
--]]

local bSucc, vRes = pcall(fnMath)   -- This calls the function in a 'safe' manner any errors thrown in fnMath won't error this program
--[[
    If no errors are thrown then bSucc will be true and vRes will contain the return value,
    Otherwise vRes will contain the error message
--]]

if not bSucc then   -- If bSucc is false we failed calling the function, print the error
    print("ERROR: "..vRes)
else
    print("Result: "..vRes)
end