util/hex.lua
author Kim Alvefur <zash@zash.se>
Sun, 14 Apr 2024 14:06:57 +0200
changeset 13483 d1b7edf4e2de
parent 12359 a0ff5c438e9d
permissions -rw-r--r--
net.unbound: Show canonical name in textual format (e.g. in shell) libunbound does not tell us the whole chain of CNAMEs, only the final canonical name. This is to aid in debugging since it will only be shown in the shell.

local s_char = string.char;
local s_format = string.format;
local s_gsub = string.gsub;
local s_lower = string.lower;

local char_to_hex = {};
local hex_to_char = {};

do
	local char, hex;
	for i = 0,255 do
		char, hex = s_char(i), s_format("%02x", i);
		char_to_hex[char] = hex;
		hex_to_char[hex] = char;
	end
end

local function to(s)
	return (s_gsub(s, ".", char_to_hex));
end

local function from(s)
	return (s_gsub(s_lower(s), "%X*(%x%x)%X*", hex_to_char));
end

return {
	encode = to, decode = from;
	-- COMPAT w/pre-0.12:
	to = to, from = from;
};