----------------------------------------------------------------------------- -- MIME support for the Lua language. -- Author: Diego Nehab -- Conforming to RFCs 2045-2049 ----------------------------------------------------------------------------- ----------------------------------------------------------------------------- -- Declare module and import dependencies ----------------------------------------------------------------------------- local base = _G local ltn12 = require("ltn12") local mime = require("mime.core") local io = require("io") local string = require("string") local _M = mime -- encode, decode and wrap algorithm tables local encodet, decodet, wrapt = {},{},{} _M.encodet = encodet _M.decodet = decodet _M.wrapt = wrapt -- creates a function that chooses a filter by name from a given table local function choose(table) return function(name, opt1, opt2) if base.type(name) ~= "string" then name, opt1, opt2 = "default", name, opt1 end local f = table[name or "nil"] if not f then base.error("unknown key (" .. base.tostring(name) .. ")", 3) else return f(opt1, opt2) end end end -- define the encoding filters encodet['base64'] = function() return ltn12.filter.cycle(_M.b64, "") end encodet['quoted-printable'] = function(mode) return ltn12.filter.cycle(_M.qp, "", (mode == "binary") and "=0D=0A" or "\r\n") end -- define the decoding filters decodet['base64'] = function() return ltn12.filter.cycle(_M.unb64, "") end decodet['quoted-printable'] = function() return ltn12.filter.cycle(_M.unqp, "") end local function format(chunk) if chunk then if chunk == "" then return "''" else return string.len(chunk) end else return "nil" end end -- define the line-wrap filters wrapt['text'] = function(length) length = length or 76 return ltn12.filter.cycle(_M.wrp, length, length) end wrapt['base64'] = wrapt['text'] wrapt['default'] = wrapt['text'] wrapt['quoted-printable'] = function() return ltn12.filter.cycle(_M.qpwrp, 76, 76) end -- function that choose the encoding, decoding or wrap algorithm _M.encode = choose(encodet) _M.decode = choose(decodet) _M.wrap = choose(wrapt) -- define the end-of-line normalization filter function _M.normalize(marker) return ltn12.filter.cycle(_M.eol, 0, marker) end -- high level stuffing filter function _M.stuff() return ltn12.filter.cycle(_M.dot, 2) end return _M