Add. pop3 example

examples/cURLv3/pop3.lua

@@ -0,0 +1,165 @@
+-- Simple pop3 wrapper
+--
+-- @usage
+--  local mbox = pop3:new('pop3://pop3.yandex.ru')
+--
+--  -- Yandex works only with tls
+--  print('Open: ', mbox:open_tls('***', '***'))
+--  print('NOOP: ', mbox:noop())
+--  print('RETR: ', mbox:retr(1))
+--
+--  list = mbox:list()
+--  for no, size in ipairs(list)do
+--  ...
+--  end
+--
+--  mbox:close()
+--
+
+local cURL = require "cURL.safe"
+
+local find_ca_bundle = require "cURL.utils".find_ca_bundle
+
+local function split(str, sep, plain)
+  local b, res = 1, {}
+  while b <= #str do
+    local e, e2 = string.find(str, sep, b, plain)
+    if e then
+      table.insert(res, (string.sub(str, b, e-1)))
+      b = e2 + 1
+    else
+      table.insert(res, (string.sub(str, b)))
+      break
+    end
+  end
+  return res
+end
+
+local crln = '\r\n'
+local function writer(cb, ctx)
+  local tail
+  return function(str)
+    if str then
+      local t = split(tail and (tail .. str) or str, crln, true)
+      if str:sub(-2) == crln then tail = nil
+      else tail = table.remove(t) end
+      for _, s in ipairs(t) do cb(ctx, s) end
+    elseif tail then cb(ctx, tail) end
+  end
+end
+
+local pop3 = {} do
+pop3.__index = pop3
+
+function pop3:new(host)
+  return setmetatable({
+    _url = assert(host)
+  },self)
+end
+
+local function open(self, user, password, ssl)
+  self._easy, err = cURL.easy{
+    url           = self._url,
+    username      = user,
+    password      = password,
+    customrequest = 'NOOP',
+    nobody        = true,
+  }
+  if not self._easy then return nil, err end
+
+  if ssl then
+    -- For AVAST
+    -- http://www.avast.com/en-eu/faq.php?article=AVKB91#artTitle
+    local cainfo, capath = find_ca_bundle('MailShield.crt')
+    if not cainfo then
+      -- On Windows try find ca_bundle
+      cainfo, capath = find_ca_bundle()
+    end
+    local ok, err = self._easy:setopt{
+      use_ssl       = cURL.USESSL_ALL,
+      cainfo        = cainfo,
+      capath        = capath,
+    }
+    if not ok then
+      self:close()
+      return nil, err
+    end
+  end
+
+  local ok, err = self._easy:perform()
+  if not ok then
+    self:close()
+    return nil, err
+  end
+
+  return self
+end
+
+function pop3:open(user, password)
+  return open(self, user, password, false)
+end
+
+function pop3:open_tls(user, password)
+  return open(self, user, password, true)
+end
+
+function pop3:noop()
+  local ok, err = self._easy:setopt{
+    url           = self._url,
+    customrequest = 'NOOP',
+    nobody        = true,
+  }
+  if not ok then return nil, err end
+  ok, err = self._easy:perform()
+  if not ok then return nil, err end
+  return self
+end
+
+function pop3:list()
+  local t = {}
+  local ok, err = self._easy:setopt{
+    url           = self._url,
+    customrequest = '',
+    nobody        = false,
+    writefunction = writer(function(t, s) t[#t+1] = s end, t)
+  }
+  if not ok then return nil, err end
+
+  ok, err = self._easy:perform()
+
+  if not ok then return nil, err end
+  return t
+end
+
+function pop3:retr(n)
+  local t = {}
+  local ok, err = self._easy:setopt{
+    url           = self._url .. '/' .. n,
+    customrequest = '',
+    nobody        = false,
+    writefunction = writer(function(t, s) t[#t+1] = s end, t)
+  }
+  if not ok then return nil, err end
+
+  ok, err = self._easy:perform()
+
+  if not ok then return nil, err end
+  return t
+end
+
+function pop3:closed()
+  return not not self._easy
+end
+
+function pop3:close()
+  if self._easy then
+    self._easy:close()
+    self._easy = false
+  end
+end
+
+end
+
+return {
+  new = function(...) return pop3:new() end;
+}