[project @ 2004-08-18 09:34:02 by simonmar]

[haskell-directory.git] / System / Directory.hs

diff --git a/System/Directory.hs b/System/Directory.hs
index 7d92473..2080af0 100644 (file)
--- a/System/Directory.hs
+++ b/System/Directory.hs
@@ -24,6 +24,8 @@ module System.Directory
     , getDirectoryContents      -- :: FilePath -> IO [FilePath]
     , getCurrentDirectory       -- :: IO FilePath
     , setCurrentDirectory       -- :: FilePath -> IO ()
+    , getHomeDirectory
+    , getAppUserDataDirectory 
 
     -- * Actions on files
     , removeFile               -- :: FilePath -> IO ()
@@ -58,6 +60,11 @@ module System.Directory
 
 #ifdef __NHC__
 import Directory
+getHomeDirectory :: IO FilePath
+getHomeDirectory = getEnv "HOME"
+getAppUserDataDirectory :: String -> IO FilePath
+getAppUserDataDirectory appName = do path <- getEnv "HOME"
+                                     return (path++'/':'.':appName)
 #elif defined(__HUGS__)
 import Hugs.Directory
 #else
@@ -78,6 +85,10 @@ import Foreign.C
 import GHC.IOBase      ( IOException(..), IOErrorType(..), ioException )
 #endif
 
+#ifndef mingw32_TARGET_OS
+import System.Environment
+#endif
+
 {- $intro
 A directory contains a series of entries, each of which is a named
 reference to a file system object (file, directory etc.).  Some
@@ -602,6 +613,92 @@ setCurrentDirectory path = do
        throwErrnoIfMinus1Retry_ "setCurrentDirectory" (c_chdir s)
        -- ToDo: add path to error
 
+{- | Returns the current user's home directory.
+
+The directory returned is expected to be writable by the current user,
+but note that it isn't generally considered good practice to store
+application-specific data here; use 'getAppUserDataDirectory'
+instead.
+
+On Unix, 'getHomeDirectory' returns the value of the @HOME@
+environment variable.  On Windows, the system is queried for a
+suitable path; a typical path might be 
+@C:/Documents And Settings/user@.
+
+The operation may fail with:
+
+* 'UnsupportedOperation'
+The operating system has no notion of home directory.
+
+* 'isDoesNotExistError'
+The home directory for the current user does not exist, or
+cannot be found.
+-}
+getHomeDirectory :: IO FilePath
+getHomeDirectory =
+#ifdef mingw32_TARGET_OS
+  allocaBytes long_path_size $ \pPath -> do
+     r <- c_SHGetFolderPath nullPtr csidl_PROFILE nullPtr 0 pPath
+     if (r < 0)
+       then c_SHGetFolderPath nullPtr csidl_WINDOWS nullPtr 0 pPath
+       else return 0
+     peekCString pPath
+#else
+  getEnv "HOME"
+#endif
+
+{- | Returns the pathname of a directory in which application-specific
+data for the current user can be stored.  The result of
+'getAppUserDataDirectory' for a given application is specific to
+the current user.
+
+The argument should be the name of the application, which will be used
+to construct the pathname (so avoid using unusual characters that
+might result in an invalid pathname).
+
+Note: the directory may not actually exist, and may need to be created
+first.  It is expected that the parent directory exists and is
+writable.
+
+On Unix, this function returns @$HOME\/.appName@.  On Windows, a
+typical path might be 
+
+> C:/Documents And Settings/user/Application Data/appName
+
+The operation may fail with:
+
+* 'UnsupportedOperation'
+The operating system has no notion of application-specific data directory.
+
+* 'isDoesNotExistError'
+The home directory for the current user does not exist, or
+cannot be found.
+-}
+getAppUserDataDirectory :: String -> IO FilePath
+getAppUserDataDirectory appName = do
+#ifdef mingw32_TARGET_OS
+  allocaBytes long_path_size $ \pPath -> do
+     r <- c_SHGetFolderPath nullPtr csidl_APPDATA nullPtr 0 pPath
+     s <- peekCString pPath
+     return (s++'\\':appName)
+#else
+  path <- getEnv "HOME"
+  return (path++'/':'.':appName)
+#endif
+
+#ifdef mingw32_TARGET_OS
+foreign import stdcall unsafe "SHGetFolderPath" 
+            c_SHGetFolderPath :: Ptr () 
+                              -> CInt 
+                              -> Ptr () 
+                              -> CInt 
+                              -> CString 
+                              -> IO CInt
+foreign import ccall unsafe "__hscore_CSIDL_PROFILE" csidl_PROFILE :: Int
+foreign import ccall unsafe "__hscore_CSIDL_APPDATA" csidl_APPDATA :: Int
+foreign import ccall unsafe "__hscore_CSIDL_WINDOWS" csidl_WINDOWS :: Int
+#endif
+
 {- |The operation 'doesDirectoryExist' returns 'True' if the argument file
 exists and is a directory, and 'False' otherwise.
 -}