import Control.Concurrent
import Control.Exception (evaluate)
+import Control.Monad (liftM)
import Data.List (intercalate)
import Data.Time (formatTime, getZonedTime)
import System.Exit
type Header = String
--- |A crude model of an RFC821 email message.
+-- | A crude model of an RFC821 email message.
data Message = Message { headers :: [Header],
subject :: String,
body :: String,
to :: String }
deriving (Eq)
--- |The default headers attached to each message.
--- The MIME junk is needed for UTF-8 to work properly.
--- Note that your mail server should support the 8BITMIME extension.
+-- | The default headers attached to each message. The MIME junk is
+-- needed for UTF-8 to work properly. Note that your mail server
+-- should support the 8BITMIME extension.
default_headers :: [Header]
default_headers = ["MIME-Version: 1.0",
"Content-Type: text/plain; charset=UTF-8",
"Content-Transfer-Encoding: 8bit"]
--- |Showing a message will print it in roughly RFC-compliant
--- form. This form is sufficient for handing the message off to
--- sendmail.
+-- | Showing a message will print it in roughly RFC-compliant
+-- form. This form is sufficient for handing the message off to
+-- sendmail (or compatible).
instance Show Message where
- show m =
- concat [ if (length (headers m) == 0) then "" else (intercalate "\n" (headers m)) ++ "\n",
- "Subject: " ++ (subject m) ++ "\n",
- "From: " ++ (from m) ++ "\n",
- "To: " ++ (to m) ++ "\n",
- "\n",
- (body m) ]
-
+ show m =
+ concat [ formatted_headers,
+ "Subject: " ++ (subject m) ++ "\n",
+ "From: " ++ (from m) ++ "\n",
+ "To: " ++ (to m) ++ "\n",
+ "\n",
+ (body m) ]
+ where
+ formatted_headers =
+ if null (headers m)
+ then ""
+ else (intercalate "\n" (headers m)) ++ "\n"
-- |Pad a string on the left with zeros until the entire string has
-- length n.
pad_left :: String -> Int -> String
pad_left str n
- | n < (length str) = str
- | otherwise = (replicate num_zeros '0') ++ str
- where num_zeros = n - (length str)
+ | n < (length str) = str
+ | otherwise = (replicate num_zeros '0') ++ str
+ where num_zeros = n - (length str)
-- | Constructs a 'String' in RFC822 date format for the current
-- date/time.
rfc822_now :: IO String
-rfc822_now = do
- date <- getZonedTime
- return $ formatTime defaultTimeLocale rfc822DateFormat date
+rfc822_now =
+ liftM (formatTime defaultTimeLocale rfc822DateFormat) getZonedTime
+
-- |Takes a message as an argument, and passes it to the system's
--- sendmail binary.
-sendmail :: Message -> IO (String, String, ExitCode)
-sendmail message = do
+-- sendmail (or compatible) binary.
+sendmail :: FilePath -> Message -> IO (String, String, ExitCode)
+sendmail sendmail_path message = do
let sendmail_args = ["-f",
- (from message)]
+ (from message),
+ (to message)]
(inh, outh, errh, ph) <-
- runInteractiveProcess "/usr/bin/sendmail" sendmail_args Nothing Nothing
+ runInteractiveProcess sendmail_path sendmail_args Nothing Nothing
outm <- newEmptyMVar
outs <- hGetContents outh
-- errors, and exit codes. This function pretty-prints one of those
-- three-tuples.
print_sendmail_result :: (String, String, ExitCode) -> IO ()
-print_sendmail_result (outs, errs, ec) = do
- case ec of
- ExitSuccess -> return ()
- _ -> putStrLn $ concat ["Output: " ++ outs,
- "\nErrors: " ++ errs,
- "\nExit Code: " ++ (show ec)]
+print_sendmail_result (outs, errs, ec) =
+ case ec of
+ ExitSuccess -> return ()
+ _ -> putStrLn $ concat ["Output: " ++ outs,
+ "\nErrors: " ++ errs,
+ "\nExit Code: " ++ (show ec)]