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Diffstat (limited to 'SetEnv.hs')
-rw-r--r-- | SetEnv.hs | 66 |
1 files changed, 66 insertions, 0 deletions
diff --git a/SetEnv.hs b/SetEnv.hs new file mode 100644 index 0000000..30f5b1e --- /dev/null +++ b/SetEnv.hs @@ -0,0 +1,66 @@ +{- + - Copyright 2015 Egor Tensin <Egor.Tensin@gmail.com> + - This file is licensed under the terms of the MIT License. + - See LICENSE.txt for details. +-} + +module Main ( main ) where + +import System.Console.GetOpt +import System.Environment ( getArgs, getProgName ) +import System.Exit ( exitFailure, exitSuccess ) +import System.IO ( hPutStr, stderr ) + +import qualified EnvUtils + +main :: IO () +main = do + rawArgs <- getArgs + case getOpt Permute optionDescription rawArgs of + (actions, args, []) -> do + options <- foldl (>>=) (return defaultOptions) actions + case args of + [name, value] -> setEnv name value options + _ -> invalidNumberOfArguments + (_, _, errorMessages) -> + exitWithUsageErrors errorMessages + +setEnv :: String -> String -> Options -> IO () +setEnv name value options = EnvUtils.saveToRegistryWithPrompt (env options) name value + +data Options = Options { env :: EnvUtils.RegistryBasedEnvironment } deriving (Eq, Show) + +defaultOptions :: Options +defaultOptions = Options { env = EnvUtils.CurrentUserEnvironment } + +buildHelpMessage :: IO String +buildHelpMessage = do + header <- buildHeader + return $ usageInfo header optionDescription + where + buildHeader :: IO String + buildHeader = do + progName <- getProgName + return $ "Usage: " ++ progName ++ " [OPTIONS...] NAME VALUE\nOptions:" + +exitWithHelpMessage :: Options -> IO a +exitWithHelpMessage _ = do + helpMessage <- buildHelpMessage + putStr helpMessage + exitSuccess + +exitWithUsageErrors :: [String] -> IO a +exitWithUsageErrors errorMessages = do + 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 = EnvUtils.AllUsersEnvironment }) "save under the registry key for all users", + Option "h" ["help"] (NoArg exitWithHelpMessage) "show this message and exit" + ] |