#!Lua-5.0.exe
-- Obfuscate an e-mail address, to avoid spam.
--
-- I use the three possible encodings: in HTML text,
-- numerical entities (decimal (of random length) and hexa),
-- in link (href) both previous and URL-encoded chars.
--
-- by Philippe Lhoste <PhiLho(a)GMX.net> http://Phi.Lho.free.fr
--
-- v. 1.3 -- 2005/08/01 -- Evenly split the three encodings, add bForLink parameter
-- v. 1.2 -- 2005/07/27 -- Also use hex values in %XX form
-- v. 1.1 -- 2004/07/19 -- Also use hex values
-- v. 1.0 -- 2003/11/12 -- First version

local email = "Philippe-Lhoste@Example.com?subject="

-- bForLink: true if result is in an href: can use URL-encoded %XX.
-- False if must be used in HTML plain text (eg. between the <a> and the </a>).
function Obfuscate(email, bForLink)
--~ 	if bForLink then
--~ 		email = "mailto:" .. email
---- Works if mailto: is encoded using entities only, eg.: &#109;ail&#116;o&#58;
--~ 	end
	return (string.gsub(email, "[-?=@._emailto:]",
			function (char)
				local b = string.byte(char); --print(b)
				if bForLink then
					r = math.random(3)
				else
					r = math.random(2)
				end
				if r == 1 then
					return string.format("&#%0" .. math.random(7) .. "d;", b)
				elseif r == 2 then
					return string.format("&#x%02X;", b)
				else
					return string.format("%%%02X", b)
				end
			end
		))
end

print(Obfuscate(email, true))
print(Obfuscate(email, false))