util/hex.lua

changeset 9
7da8b3c95bb1
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/util/hex.lua	Mon Jan 04 12:00:03 2016 +0000
@@ -0,0 +1,26 @@
+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 { to = to, from = from }

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