Expose getPath

.github/workflows/build.yml

@@ -22,9 +22,9 @@ jobs:
           - { os: ubuntu-latest, ghc: 9.4.3, cabal: 3.8.1.0 }
           # TODO: Unpin cabal from 3.12.10 after https://github.com/haskell/cabal/issues/10718 is fixed.
           - { os: ubuntu-latest, ghc: latest, cabal: 3.12.1.0, cabal-package-flags: +os-string, ghc-flags: -Werror=deprecations }
-          - { os: windows-latest, stack: lts-15.3, stack-extra-deps: "bytestring-0.11.3.0, file-io-0.1.4, filepath-1.4.100.0, time-1.9.3, Win32-2.13.3.0", overrides: "before_prepare() { sed -i.bak -e /CreateSymbolicLinkW/d -e /GetFinalPathNameByHandleW/d configure.ac; }" }
-          - { os: windows-latest, stack: lts-17.5, stack-extra-deps: "bytestring-0.11.3.0, file-io-0.1.4, filepath-1.4.100.0, time-1.9.3, Win32-2.13.3.0" }
-          - { os: windows-latest, stack: lts-22.7, stack-extra-deps: "bytestring-0.11.5.3, file-io-0.1.4, filepath-1.5.2.0, os-string-2.0.2, time-1.14, Win32-2.14.0.0", stack-package-flags: "{directory: {os-string: true}, file-io: {os-string: true}, Win32: {os-string: true}}", ghc-flags: -Werror=deprecations }
+          - { os: windows-latest, stack: lts-15.3, stack-extra-deps: "bytestring-0.11.3.0, file-io-0.1.4, filepath-1.4.100.0, time-1.9.3, Win32-2.14.1.0", overrides: "before_prepare() { sed -i.bak -e /CreateSymbolicLinkW/d -e /GetFinalPathNameByHandleW/d configure.ac; }" }
+          - { os: windows-latest, stack: lts-17.5, stack-extra-deps: "bytestring-0.11.3.0, file-io-0.1.4, filepath-1.4.100.0, time-1.9.3, Win32-2.14.1.0" }
+          - { os: windows-latest, stack: lts-22.7, stack-extra-deps: "bytestring-0.11.5.3, file-io-0.1.4, filepath-1.5.2.0, os-string-2.0.2, time-1.14, Win32-2.14.1.0", stack-package-flags: "{directory: {os-string: true}, file-io: {os-string: true}, Win32: {os-string: true}}", ghc-flags: -Werror=deprecations }
     runs-on: ${{ matrix.os }}
     env:
       CABAL_PACKAGE_FLAGS: ${{ matrix.cabal-package-flags }}

System/Directory.hs

@@ -40,6 +40,9 @@ module System.Directory
     , getUserDocumentsDirectory
     , getTemporaryDirectory
 
+    -- * PATH
+    , System.Directory.getPath
+
     -- * Actions on files
     , removeFile
     , renameFile
@@ -1337,3 +1340,7 @@ The function doesn\'t verify whether the path exists.
 -}
 getTemporaryDirectory :: IO FilePath
 getTemporaryDirectory = D.getTemporaryDirectory >>= decodeFS
+
+-- | Get the contents of the @PATH@ environment variable.
+getPath :: IO [FilePath]
+getPath = D.getPath >>= (`for` decodeFS)

System/Directory/Internal/Posix.hsc

@@ -148,6 +148,10 @@ findExecutablesLazyInternal findExecutablesInDirectoriesLazy binary =
     path <- getPath
     pure (findExecutablesInDirectoriesLazy path binary)
 
+-- | Get the contents of the @PATH@ environment variable.
+getPath :: IO [OsPath]
+getPath = splitSearchPath <$> getEnvOs (os "PATH")
+
 exeExtensionInternal :: OsString
 exeExtensionInternal = exeExtension
 
@@ -391,10 +395,6 @@ getEnvOs name = do
           Nothing
     Just value -> pure value
 
--- | Get the contents of the @PATH@ environment variable.
-getPath :: IO [OsPath]
-getPath = splitSearchPath <$> getEnvOs (os "PATH")
-
 -- | $HOME is preferred, because the user has control over it. However, POSIX
 -- doesn't define it as a mandatory variable, so fall back to `getpwuid_r`.
 getHomeDirectoryInternal :: IO OsPath

System/Directory/Internal/Windows.hsc

@@ -29,6 +29,7 @@ import System.OsPath
   , pack
   , pathSeparator
   , splitDirectories
+  , splitSearchPath
   , takeExtension
   , toChar
   , unpack
@@ -41,6 +42,7 @@ import qualified System.Win32.WindowsString.Info as Win32
 import qualified System.Win32.WindowsString.Shell as Win32
 import qualified System.Win32.WindowsString.Time as Win32
 import qualified System.Win32.WindowsString.Types as Win32
+import qualified System.Win32.WindowsString.Console as Win32
 
 type RawHandle = OsPath
 
@@ -53,6 +55,26 @@ openRaw _ dir path = pure (pathAt dir path)
 closeRaw :: RawHandle -> IO ()
 closeRaw _ = pure ()
 
+lookupEnvOs :: OsString -> IO (Maybe OsString)
+lookupEnvOs (OsString name) = (OsString <$>) <$> Win32.getEnv name
+
+getEnvOs :: OsString -> IO OsString
+getEnvOs name = do
+  env <- lookupEnvOs name
+  case env of
+    Nothing ->
+      throwIO $
+        mkIOError
+          doesNotExistErrorType
+          ("env var " <> show name <> " not found")
+          Nothing
+          Nothing
+    Just value -> pure value
+
+-- | Get the contents of the @PATH@ environment variable.
+getPath :: IO [OsPath]
+getPath = splitSearchPath <$> getEnvOs (os "PATH")
+
 createDirectoryInternal :: OsPath -> IO ()
 createDirectoryInternal path =
   (`ioeSetOsPath` path) `modifyIOError` do
@@ -666,24 +688,6 @@ setAccessPermissions :: OsPath -> Permissions -> IO ()
 setAccessPermissions path Permissions{writable = w} = do
   setFilePermissions path (setWriteMode w 0)
 
-lookupEnvOs :: OsString -> IO (Maybe OsString)
-lookupEnvOs (OsString name) = do
-  result <-
-    Win32.withTString name $ \ pName ->
-    peekTStringWith 256 $ \ pBuffer size ->
-    c_GetEnvironmentVariable pName pBuffer size
-  case result of
-    Left errCode | errCode == win32_eRROR_ENVVAR_NOT_FOUND -> pure Nothing
-                 | otherwise -> Win32.failWith "GetEnvironmentVariable" errCode
-    Right value -> pure (Just (OsString value))
-
-foreign import WINAPI unsafe "windows.h GetEnvironmentVariableW"
-  c_GetEnvironmentVariable
-    :: Win32.LPWSTR
-    -> Win32.LPWSTR
-    -> Win32.DWORD
-    -> IO Win32.DWORD
-
 getFolderPath :: Win32.CSIDL -> IO OsPath
 getFolderPath what = OsString <$> Win32.sHGetFolderPath nullPtr what nullPtr 0
 

System/Directory/OsPath.hs

@@ -42,6 +42,9 @@ module System.Directory.OsPath
     , getUserDocumentsDirectory
     , getTemporaryDirectory
 
+    -- * PATH
+    , getPath
+
     -- * Actions on files
     , removeFile
     , renameFile
@@ -1653,3 +1656,4 @@ The function doesn\'t verify whether the path exists.
 -}
 getTemporaryDirectory :: IO OsPath
 getTemporaryDirectory = getTemporaryDirectoryInternal
+

changelog.md

@@ -1,6 +1,10 @@
 Changelog for the [`directory`][1] package
 ==========================================
 
+## 1.3.10.0 (XXX 2025)
+
+  * Add `getPath` wrt [#198](https://github.com/haskell/directory/pull/198)
+
 ## 1.3.9.0 (Oct 2024)
 
   * Rely on `file-io` for file I/O.

directory.cabal

@@ -1,6 +1,6 @@
 cabal-version:  2.2
 name:           directory
-version:        1.3.9.0
+version:        1.3.10.0
 license:        BSD-3-Clause
 license-file:   LICENSE
 maintainer:     libraries@haskell.org
@@ -63,7 +63,7 @@ Library
         file-io  >= 0.1.4 && < 0.2,
         time     >= 1.8.0 && < 1.15,
     if os(windows)
-        build-depends: Win32 >= 2.13.3 && < 2.15
+        build-depends: Win32 >= 2.14.1.0 && < 2.15
     else
         build-depends: unix >= 2.8.0 && < 2.9