paths: add "current"/"all users" options

1 files changed, 23 insertions, 4 deletions

diff --git a/apps/ListPath.hs b/apps/ListPath.hs
index ebc9188..65d374b 100644
--- a/apps/ListPath.hs
+++ b/apps/ListPath.hs
@@ -7,9 +7,12 @@
 module Main (main) where
 
 import Control.Monad      (filterM)
+import Control.Monad.Trans.Class  (lift)
+import Control.Monad.Trans.Except (runExceptT)
 import Data.Maybe         (fromMaybe)
 import System.Directory   (doesDirectoryExist)
 import System.Environment (lookupEnv)
+import System.IO.Error    (ioError)
 
 import Options.Applicative
 
@@ -23,15 +26,20 @@ shouldListPath All = return . const True
 shouldListPath ExistingOnly = doesDirectoryExist
 shouldListPath MissingOnly  = fmap not . doesDirectoryExist
 
+data Source = Environment | Registry Env.Profile
+            deriving (Eq, Show)
+
 data Options = Options
     { optName       :: Env.VarName
     , optWhichPaths :: WhichPaths
+    , optSource     :: Source
     } deriving (Eq, Show)
 
 optionParser :: Parser Options
 optionParser = Options
     <$> optNameDesc
     <*> optWhichPathsDesc
+    <*> optSourceDesc
   where
     optNameDesc = strOption
          $ long "name" <> short 'n'
@@ -42,6 +50,11 @@ optionParser = Options
             <> help "List existing paths only")
         <|> flag' MissingOnly (long "missing" <> short 'm'
             <> help "List missing paths only")
+    optSourceDesc = pure Environment
+        <|> flag' (Registry Env.CurrentUser) (long "user" <> short 'u'
+            <> help "List current user's paths only")
+        <|> flag' (Registry Env.AllUsers) (long "global" <> short 'g'
+            <> help "List global (all users') paths only")
 
 main :: IO ()
 main = execParser parser >>= listPath
@@ -50,14 +63,20 @@ main = execParser parser >>= listPath
         fullDesc <> progDesc "List directories in your PATH"
 
 listPath :: Options -> IO ()
-listPath options = do
-    oldValue <- query
-    printPaths $ Env.pathSplit oldValue
+listPath options = runExceptT doListPath >>= either ioError return
   where
     varName = optName options
     whichPaths = optWhichPaths options
+    source = optSource options
+
+    query = queryFrom source
+
+    queryFrom Environment = lift $ fromMaybe "" <$> lookupEnv varName
+    queryFrom (Registry profile) = Env.query profile varName
 
-    query = fromMaybe "" <$> lookupEnv varName
+    doListPath = do
+        paths <- query
+        lift $ printPaths $ Env.pathSplit paths
 
     printPaths paths =
         filterM (shouldListPath whichPaths) paths >>= mapM_ putStrLn