File

mod_http_file_share: Use alternate syntax for filename in Content-Disposition The Lua string.format %q doesn't behave correctly for all characters that should be escaped in a quoted-string. And who knows what effects higher Unicode might have here. Applying percent-encoding of filenames seems like the safest way to deal with filenames, as well as being easier than implementing the actual quoted-string transform, which seems complicated and I'm not even sure it covers every possible character. Filenames can safely be assumed to be UTF-8 since they are passed in an attribute in the query without any escaping.

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 }