1 {-# LANGUAGE DeriveDataTypeable #-}
6 import System.Console.CmdArgs
7 import System.Console.CmdArgs.Explicit (process)
8 import System.Environment (getArgs, withArgs)
9 import System.Exit (ExitCode(..), exitWith)
10 import System.IO (hPutStrLn, stderr)
12 -- Get the version from Cabal.
13 import Paths_email_validator (version)
14 import Data.Version (showVersion)
18 -- We optionally accept input/output files to use instead of
20 data Args = Args { input_file :: Maybe FilePath,
21 output_file :: Maybe FilePath }
22 deriving (Show, Data, Typeable)
25 description = "Perform naive validation of email addresses."
27 program_name :: String
28 program_name = "email-validator"
31 my_summary = program_name ++ "-" ++ (showVersion version)
33 input_file_help :: String
35 "Path to the input file (default: stdin), one email address per line"
37 output_file_help :: String
39 "Path to the output file (default: stdout)"
41 arg_spec :: Mode (CmdArgs Args)
44 Args { input_file = def &= typFile &= help input_file_help,
45 output_file = def &= typFile &= help output_file_help }
46 &= program program_name
48 &= details [description]
50 show_help :: IO (CmdArgs Args)
51 show_help = withArgs ["--help"] parse_args
55 parse_args :: IO (CmdArgs Args)
58 let y = process arg_spec x
60 Right result -> return result
63 exitWith (ExitFailure exit_args_parse_failed)
66 -- | Really get the command-line arguments. This calls 'parse_args'
67 -- first to replace the default "wrong number of arguments" error,
68 -- and then runs 'cmdArgsApply' on the result to do what the
69 -- 'cmdArgs' function usually does.
72 parse_args >>= cmdArgsApply