| ----------------------------------------------------------------------------- |
| -- MIME support for the Lua language. |
| -- Author: Diego Nehab |
| -- Conforming to RFCs 2045-2049 |
| -- RCS ID: $Id: mime.lua,v 1.29 2007/06/11 23:44:54 diego Exp $ |
| ----------------------------------------------------------------------------- |
| |
| ----------------------------------------------------------------------------- |
| -- 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") |
| module("mime") |
| |
| -- encode, decode and wrap algorithm tables |
| encodet = {} |
| decodet = {} |
| 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(b64, "") |
| end |
| |
| encodet['quoted-printable'] = function(mode) |
| return ltn12.filter.cycle(qp, "", |
| (mode == "binary") and "=0D=0A" or "\r\n") |
| end |
| |
| -- define the decoding filters |
| decodet['base64'] = function() |
| return ltn12.filter.cycle(unb64, "") |
| end |
| |
| decodet['quoted-printable'] = function() |
| return ltn12.filter.cycle(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(wrp, length, length) |
| end |
| wrapt['base64'] = wrapt['text'] |
| wrapt['default'] = wrapt['text'] |
| |
| wrapt['quoted-printable'] = function() |
| return ltn12.filter.cycle(qpwrp, 76, 76) |
| end |
| |
| -- function that choose the encoding, decoding or wrap algorithm |
| encode = choose(encodet) |
| decode = choose(decodet) |
| wrap = choose(wrapt) |
| |
| -- define the end-of-line normalization filter |
| function normalize(marker) |
| return ltn12.filter.cycle(eol, 0, marker) |
| end |
| |
| -- high level stuffing filter |
| function stuff() |
| return ltn12.filter.cycle(dot, 2) |
| end |