prosody, prosodyctl: Load loader directly from source directory This should ensure that loader.lua is loaded from the source directory and does the right thing when installed with `make install` There are currently three ways Prosody can be run: - Directly from the source directory, like `./prosody` - Installed with `make install` - Installed into Lua paths with e.g. dh-lua or luarocks In the first two cases, Lua search paths need to include the source directory and ensure that `require "prosody.util.json"` ends up loading `util/json.lua` relative to the installation (CFG_SOURCEDIR) or the source checkout. Finally, in the last case where Prosody resources are installed under the 'prosody.*' namespace in regular Lua search paths, then loader.lua should activate the compatibility mode that makes sure that both `require"util.json"` and `require"prosody.util.json"` both resolve to `(one path from of package.path)/prosody/util/json.lua`

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;
};