diff options
Diffstat (limited to 'apps/UnsetEnv.hs')
-rw-r--r-- | apps/UnsetEnv.hs | 63 |
1 files changed, 33 insertions, 30 deletions
diff --git a/apps/UnsetEnv.hs b/apps/UnsetEnv.hs index 254f383..32626f3 100644 --- a/apps/UnsetEnv.hs +++ b/apps/UnsetEnv.hs @@ -4,62 +4,65 @@ - See LICENSE.txt for details. -} -module Main ( main ) where +module Main (main) where import System.Console.GetOpt -import System.Environment ( getArgs, getProgName ) -import System.Exit ( exitFailure, exitSuccess ) -import System.IO ( hPutStr, stderr ) +import System.Environment (getArgs, getProgName) +import System.Exit (exitFailure, exitSuccess) +import System.IO (hPutStr, stderr) import qualified Environment main :: IO () main = do - rawArgs <- getArgs - case getOpt Permute optionDescription rawArgs of - (actions, args, []) -> do - options <- foldl (>>=) (return defaultOptions) actions - case args of - [name] -> unsetEnv name options - _ -> invalidNumberOfArguments - (_, _, errorMessages) -> exitWithUsageErrors errorMessages + rawArgs <- getArgs + case getOpt Permute optionDescription rawArgs of + (actions, args, []) -> do + options <- foldl (>>=) (return defaultOptions) actions + case args of + [name] -> unsetEnv name options + _ -> invalidNumberOfArguments + (_, _, errorMessages) -> exitWithUsageErrors errorMessages unsetEnv :: String -> Options -> IO () unsetEnv name options = Environment.wipeFromRegistryWithPrompt (env options) name -data Options = Options { env :: Environment.RegistryBasedEnvironment } deriving (Eq, Show) +data Options = Options + { env :: Environment.RegistryBasedEnvironment + } deriving (Eq, Show) defaultOptions :: Options -defaultOptions = Options { env = Environment.CurrentUserEnvironment } +defaultOptions = Options + { env = Environment.CurrentUserEnvironment + } buildHelpMessage :: IO String buildHelpMessage = do - header <- buildHeader - return $ usageInfo header optionDescription - where - buildHeader :: IO String - buildHeader = do + header <- buildHeader + return $ usageInfo header optionDescription + where + buildHeader = do progName <- getProgName return $ "Usage: " ++ progName ++ " [OPTIONS...] NAME\nOptions:" exitWithHelpMessage :: a -> IO b exitWithHelpMessage _ = do - helpMessage <- buildHelpMessage - putStr helpMessage - exitSuccess + helpMessage <- buildHelpMessage + putStr helpMessage + exitSuccess exitWithUsageErrors :: [String] -> IO a exitWithUsageErrors errorMessages = do - hPutStr stderr $ concatMap ("Usage error: " ++) errorMessages - helpMessage <- buildHelpMessage - hPutStr stderr helpMessage - exitFailure + hPutStr stderr $ concatMap ("Usage error: " ++) errorMessages + helpMessage <- buildHelpMessage + hPutStr stderr helpMessage + exitFailure invalidNumberOfArguments :: IO a invalidNumberOfArguments = exitWithUsageErrors ["invalid number of arguments\n"] optionDescription :: [OptDescr (Options -> IO Options)] -optionDescription = [ - Option "g" ["global"] (NoArg $ \opts -> return opts { env = Environment.AllUsersEnvironment }) "delete from the registry key for all users", - Option "h" ["help"] (NoArg exitWithHelpMessage) "show this message and exit" - ] +optionDescription = + [ Option "g" ["global"] (NoArg $ \opts -> return opts { env = Environment.AllUsersEnvironment }) "delete from the registry key for all users" + , Option "h" ["help"] (NoArg exitWithHelpMessage) "show this message and exit" + ] |