util/hex.lua

   1 local s_char = string.char;
   2 local s_format = string.format;
   3 local s_gsub = string.gsub;
   4 local s_lower = string.lower;
   5
   6 local char_to_hex = {};
   7 local hex_to_char = {};
   8
   9 do
  10         local char, hex;
  11         for i = 0,255 do
  12                 char, hex = s_char(i), s_format("%02x", i);
  13                 char_to_hex[char] = hex;
  14                 hex_to_char[hex] = char;
  15         end
  16 end
  17
  18 local function to(s)
  19         return (s_gsub(s, ".", char_to_hex));
  20 end
  21
  22 local function from(s)
  23         return (s_gsub(s_lower(s), "%X*(%x%x)%X*", hex_to_char));
  24 end
  25
  26 return { to = to, from = from }