Hex manipulation

[admin]

Of course second one does not work because '7F' == string.char(0x37, 0x46). If you want to send hex string as binary you have to convert it using lmcore.hextostr(str, true) or use string.char.

If by inversion you mean binary XOR, then your function should look like this:

Code:

function convert(str)
  local res, byte

  res = ''
  -- discard last 2 bytes
  for i = 1, #str - 2 do
    -- get single byte
    byte = str:byte(i, i)
    -- invert
    byte = bit.bxor(byte, 0xFF)
    -- add to result
    res = res .. string.char(byte)
  end

  return res
end