From 7c12f0ac9224246dac308e837bccb5b2157062ee Mon Sep 17 00:00:00 2001 From: Joey Hess Date: Tue, 15 Dec 2015 17:47:59 -0700 Subject: Import git-repair_1.20151215.orig.tar.xz [dgit import orig git-repair_1.20151215.orig.tar.xz] --- Utility/Env.hs | 84 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 84 insertions(+) create mode 100644 Utility/Env.hs (limited to 'Utility/Env.hs') diff --git a/Utility/Env.hs b/Utility/Env.hs new file mode 100644 index 0000000..c56f4ec --- /dev/null +++ b/Utility/Env.hs @@ -0,0 +1,84 @@ +{- portable environment variables + - + - Copyright 2013 Joey Hess + - + - License: BSD-2-clause + -} + +{-# LANGUAGE CPP #-} +{-# OPTIONS_GHC -fno-warn-tabs #-} + +module Utility.Env where + +#ifdef mingw32_HOST_OS +import Utility.Exception +import Control.Applicative +import Data.Maybe +import Prelude +import qualified System.Environment as E +import qualified System.SetEnv +#else +import qualified System.Posix.Env as PE +#endif + +getEnv :: String -> IO (Maybe String) +#ifndef mingw32_HOST_OS +getEnv = PE.getEnv +#else +getEnv = catchMaybeIO . E.getEnv +#endif + +getEnvDefault :: String -> String -> IO String +#ifndef mingw32_HOST_OS +getEnvDefault = PE.getEnvDefault +#else +getEnvDefault var fallback = fromMaybe fallback <$> getEnv var +#endif + +getEnvironment :: IO [(String, String)] +#ifndef mingw32_HOST_OS +getEnvironment = PE.getEnvironment +#else +getEnvironment = E.getEnvironment +#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 + +{- Adds the environment variable to the input environment. If already + - present in the list, removes the old value. + - + - This does not really belong here, but Data.AssocList is for some reason + - buried inside hxt. + -} +addEntry :: Eq k => k -> v -> [(k, v)] -> [(k, v)] +addEntry k v l = ( (k,v) : ) $! delEntry k l + +addEntries :: Eq k => [(k, v)] -> [(k, v)] -> [(k, v)] +addEntries = foldr (.) id . map (uncurry addEntry) . reverse + +delEntry :: Eq k => k -> [(k, v)] -> [(k, v)] +delEntry _ [] = [] +delEntry k (x@(k1,_) : rest) + | k == k1 = rest + | otherwise = ( x : ) $! delEntry k rest -- cgit v1.2.3