Try String.codepoints/1. Where the code point can’t be decoded to UTF-8 you’ll see a number.
iex> String.codepoints x
["a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l", "m", "n", "o", "p",
"q", "r", "s", "t", "u", "v", "w", "x", "y", "z", ".", ".", ".", ".", "0", "1",
"2", "3", "4", "5", "6", "7", "8", "9", " ", "不", "極", "，", "物", "片",
"類", "書", "車", "裡", ...]
If you want to get the numeric value, add <<0>> to the string:
iex> x <> <<0>>
<<97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112,
113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 46, 46, 46, 46, 48, 49, 50,
51, 52, 53, 54, 55, 56, 57, 32, 228, 184, 141, 230, 165, 181, 239, 188, 140,
...>>
If you want the raw integers underneath use to_charlist/1:
iex> to_charlist x
[97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112,
113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 46, 46, 46, 46, 48, 49, 50,
51, 52, 53, 54, 55, 56, 57, 32, 19981, 26997, 65292, 29289, 29255, 39006,
26360, 36554, 35041, ...]
