{- portable environment variables - - Copyright 2013 Joey Hess - - License: BSD-2-clause -} {-# LANGUAGE CPP #-} module Utility.Env.Set where #ifdef mingw32_HOST_OS import qualified System.Environment as E import qualified System.SetEnv import Utility.Env #else import qualified System.Posix.Env as PE #endif {- Sets an environment variable. To overwrite an existing variable, - overwrite must be True. - - On Windows, setting a variable to "" unsets it. -} setEnv :: String -> String -> Bool -> IO () #ifndef mingw32_HOST_OS setEnv var val overwrite = PE.setEnv var val overwrite #else setEnv var val True = System.SetEnv.setEnv var val setEnv var val False = do r <- getEnv var case r of Nothing -> setEnv var val True Just _ -> return () #endif unsetEnv :: String -> IO () #ifndef mingw32_HOST_OS unsetEnv = PE.unsetEnv #else unsetEnv = System.SetEnv.unsetEnv #endif