X-Git-Url: https://gitweb.michael.orlitzky.com/?a=blobdiff_plain;f=src%2FMain.hs;h=1cc4c73aa47d963e56f30a7188f05781f010b76c;hb=2e8aab2a69a8b9887e4f037115b80a2063d3a6b7;hp=fc1b1b18eba02c44d549de693cc8f3d65fd6ea1e;hpb=031638c08a4ce9d7ea156ead71cb8ef02e23fa81;p=email-validator.git

diff --git a/src/Main.hs b/src/Main.hs
index fc1b1b1..1cc4c73 100644
--- a/src/Main.hs
+++ b/src/Main.hs
@@ -1,52 +1,55 @@
 {-# LANGUAGE DoAndIfThenElse #-}
 {-# LANGUAGE RecordWildCards #-}
 
-module Main
+module Main (main)
 where
 
-import Control.Concurrent.ParallelIO.Global (parallel, stopGlobalPool)
-import Control.Monad (unless)
-import qualified Data.ByteString as BS
-import qualified Data.ByteString.UTF8 as BSU
+import Control.Concurrent.ParallelIO.Global (
+   parallelInterleaved,
+   stopGlobalPool )
+import qualified Data.ByteString.Char8 as BS (
+  hGetContents,
+  hPutStrLn,
+  lines,
+  null,
+  pack )
 import Network.DNS (
   Domain,
   Resolver,
-  ResolvConf(..),
+  ResolvConf( resolvTimeout ),
   defaultResolvConf,
   makeResolvSeed,
-  withResolver)
-import Network.DNS.Lookup (lookupA, lookupMX)
-import System.Directory (doesFileExist)
-import System.Exit (exitWith, ExitCode(..))
+  withResolver )
+import Network.DNS.Lookup ( lookupA, lookupMX )
 import System.IO (
-  Handle,
-  IOMode( WriteMode ),
-  hClose,
   hFlush,
-  openFile,
   stdin,
-  stdout)
+  stdout )
 
 
-import CommandLine (Args(..), apply_args)
-import EmailAddress
-import ExitCodes (exit_input_file_doesnt_exist)
+import CommandLine (
+  Args( Args, accept_a, rfc5322 ),
+  get_args )
+import EmailAddress(
+  Address,
+  parts,
+  validate_syntax )
 
 
--- | Resolver parameters. We increase the default timeout from 3 to 5
+-- | Resolver parameters. We increase the default timeout from 3 to 10
 --   seconds.
 resolv_conf ::  ResolvConf
-resolv_conf = defaultResolvConf { resolvTimeout = 5 * 1000 * 1000 }
+resolv_conf = defaultResolvConf { resolvTimeout = 10 * 1000 * 1000 }
 
 -- | A list of common domains, there's no need to waste MX lookups
 --   on these.
 common_domains :: [Domain]
-common_domains = map BSU.fromString [ "aol.com",
-                                      "comcast.net",
-                                      "gmail.com",
-                                      "msn.com",
-                                      "yahoo.com",
-                                      "verizon.net" ]
+common_domains = map BS.pack [ "aol.com",
+                               "comcast.net",
+                               "gmail.com",
+                               "msn.com",
+                               "yahoo.com",
+                               "verizon.net" ]
 
 
 -- | Check whether the given domain has a valid MX record.
@@ -56,8 +59,9 @@ validate_mx resolver domain
   | otherwise = do
       result <- lookupMX resolver domain
       case result of
-        Nothing -> return False
-        _       -> return True
+        -- A list of one or more elements?
+        Right (_:_) -> return True
+        _           -> return False
 
 
 -- | Check whether the given domain has a valid A record.
@@ -67,16 +71,16 @@ validate_a resolver domain
   | otherwise = do
       result <- lookupA resolver domain
       case result of
-        Nothing -> return False
-        _       -> return True
+        Right (_:_) -> return True
+        _           -> return False
 
 
 -- | Validate an email address by doing some simple syntax checks and
 --   (if those fail) an MX lookup. We don't count an A record as a mail
 --   exchanger.
-validate :: Resolver -> Bool -> Address -> IO (Address, Bool)
-validate resolver accept_a address = do
-  let valid_syntax = validate_syntax address
+validate :: Resolver -> Bool -> Bool -> Address -> IO (Address, Bool)
+validate resolver accept_a rfc5322 address = do
+  let valid_syntax = validate_syntax rfc5322 address
   if valid_syntax then do
     let (_,domain) = parts address
     mx_result <- validate_mx resolver domain
@@ -93,52 +97,35 @@ validate resolver accept_a address = do
     return (address, False)
 
 
--- | Append a ByteString to a file Handle, followed by a newline.
-append_handle_with_newline :: Handle -> BS.ByteString -> IO ()
-append_handle_with_newline h bs = do
-  BS.hPutStr h bs
-  BS.hPutStr h newline
-  where
-    newline = BSU.fromString "\n"
-
 
 main :: IO ()
 main = do
-  Args{..} <- apply_args
-
-  -- Get the input from either stdin, or the file given on the command
-  -- line.
-  input <- case input_file of
-             Nothing   -> BS.hGetContents stdin
-             Just path -> do
-               is_file <- doesFileExist path
-               unless is_file $
-                 exitWith (ExitFailure exit_input_file_doesnt_exist)
-               BS.readFile path
-
-  -- Do the same for the output handle and stdout.
-  output_handle <- case output_file of
-                     Nothing -> return stdout
-                     Just path -> openFile path WriteMode
-
-  -- Split the input into lines.
-  let addresses = BSU.lines input
+  Args{..} <- get_args
+
+  -- Split stdin into lines, which should result in a list of addresses.
+  input <- BS.hGetContents stdin
+  let addresses = BS.lines input
 
   -- And remove the empty ones.
   let nonempty_addresses = filter (not . BS.null) addresses
 
   rs <- makeResolvSeed resolv_conf
-  withResolver rs $ \resolver -> do
-    -- Construst a list of [IO (Address, Bool)]
-    let actions = map (validate resolver accept_a) nonempty_addresses
-    -- And compute them in parallel.
-    results <- parallel actions
-    stopGlobalPool
-    -- Find the pairs with a True in the second position.
-    let good_pairs = filter snd results
-    -- And output the results.
-    mapM_ ((append_handle_with_newline output_handle) . fst) good_pairs
-
-  -- Clean up. It's safe to try to close stdout.
-  hFlush output_handle
-  hClose output_handle
+  let validate' addr = withResolver rs $ \resolver ->
+                         validate resolver accept_a rfc5322 addr
+
+  -- Construct a list of [IO (Address, Bool)]. The withResolver calls
+  -- are the ones that should be run in parallel.
+  let actions = map validate' nonempty_addresses
+
+  -- Run the lookup actions in parallel.
+  results <- parallelInterleaved actions
+
+  -- Filter the bad ones.
+  let valid_results = filter snd results
+
+  -- Output the results.
+  let valid_addresses = map fst valid_results
+  mapM_ (BS.hPutStrLn stdout) valid_addresses
+
+  stopGlobalPool
+  hFlush stdout