{-# LINE 1 "System/Posix/Files.hsc" #-}
{-# LANGUAGE ForeignFunctionInterface #-}
{-# LINE 2 "System/Posix/Files.hsc" #-}
{-# OPTIONS_GHC -fno-warn-unused-imports #-}

{-# LINE 4 "System/Posix/Files.hsc" #-}
{-# LANGUAGE Trustworthy #-}

{-# LINE 6 "System/Posix/Files.hsc" #-}
-----------------------------------------------------------------------------
-- |
-- Module      :  System.Posix.Files
-- Copyright   :  (c) The University of Glasgow 2002
-- License     :  BSD-style (see the file libraries/base/LICENSE)
-- 
-- Maintainer  :  libraries@haskell.org
-- Stability   :  provisional
-- Portability :  non-portable (requires POSIX)
--
-- Functions defined by the POSIX standards for manipulating and querying the
-- file system. Names of underlying POSIX functions are indicated whenever
-- possible. A more complete documentation of the POSIX functions together
-- with a more detailed description of different error conditions are usually
-- available in the system's manual pages or from
-- <http://www.unix.org/version3/online.html> (free registration required).
--
-- When a function that calls an underlying POSIX function fails, the errno
-- code is converted to an 'IOError' using 'Foreign.C.Error.errnoToIOError'.
-- For a list of which errno codes may be generated, consult the POSIX
-- documentation for the underlying function.
--
-----------------------------------------------------------------------------


{-# LINE 31 "System/Posix/Files.hsc" #-}

module System.Posix.Files (
    -- * File modes
    -- FileMode exported by System.Posix.Types
    unionFileModes, intersectFileModes,
    nullFileMode,
    ownerReadMode, ownerWriteMode, ownerExecuteMode, ownerModes,
    groupReadMode, groupWriteMode, groupExecuteMode, groupModes,
    otherReadMode, otherWriteMode, otherExecuteMode, otherModes,
    setUserIDMode, setGroupIDMode,
    stdFileMode,   accessModes,
    fileTypeModes,
    blockSpecialMode, characterSpecialMode, namedPipeMode, regularFileMode,
    directoryMode, symbolicLinkMode, socketMode,

    -- ** Setting file modes
    setFileMode, setFdMode, setFileCreationMask,

    -- ** Checking file existence and permissions
    fileAccess, fileExist,

    -- * File status
    FileStatus,
    -- ** Obtaining file status
    getFileStatus, getFdStatus, getSymbolicLinkStatus,
    -- ** Querying file status
    deviceID, fileID, fileMode, linkCount, fileOwner, fileGroup,
    specialDeviceID, fileSize, accessTime, modificationTime,
    statusChangeTime,
    accessTimeHiRes, modificationTimeHiRes, statusChangeTimeHiRes,
    isBlockDevice, isCharacterDevice, isNamedPipe, isRegularFile,
    isDirectory, isSymbolicLink, isSocket,

    -- * Creation
    createNamedPipe, 
    createDevice,

    -- * Hard links
    createLink, removeLink,

    -- * Symbolic links
    createSymbolicLink, readSymbolicLink,

    -- * Renaming files
    rename,

    -- * Changing file ownership
    setOwnerAndGroup,  setFdOwnerAndGroup,

{-# LINE 80 "System/Posix/Files.hsc" #-}
    setSymbolicLinkOwnerAndGroup,

{-# LINE 82 "System/Posix/Files.hsc" #-}

    -- * Changing file timestamps
    setFileTimes, touchFile,

    -- * Setting file sizes
    setFileSize, setFdSize,

    -- * Find system-specific limits for a file
    PathVar(..), getPathVar, getFdPathVar,
  ) where


import Foreign
import Foreign.C

import System.Posix.Error
import System.Posix.Types
import System.Posix.Internals
import System.Posix.Files.Common


{-# LINE 103 "System/Posix/Files.hsc" #-}
import System.Posix.Internals (withFilePath, peekFilePath)

{-# LINE 122 "System/Posix/Files.hsc" #-}

-- -----------------------------------------------------------------------------
-- chmod()

-- | @setFileMode path mode@ changes permission of the file given by @path@
-- to @mode@. This operation may fail with 'throwErrnoPathIfMinus1_' if @path@
-- doesn't exist or if the effective user ID of the current process is not that
-- of the file's owner.
--
-- Note: calls @chmod@.
setFileMode :: FilePath -> FileMode -> IO ()
setFileMode name m =
  withFilePath name $ \s -> do
    throwErrnoPathIfMinus1_ "setFileMode" name (c_chmod s m)

-- -----------------------------------------------------------------------------
-- access()

-- | @fileAccess name read write exec@ checks if the file (or other file system
-- object) @name@ can be accessed for reading, writing and\/or executing. To
-- check a permission set the corresponding argument to 'True'.
--
-- Note: calls @access@.
fileAccess :: FilePath -> Bool -> Bool -> Bool -> IO Bool
fileAccess name readOK writeOK execOK = access name flags
  where
   flags   = read_f .|. write_f .|. exec_f
   read_f  = if readOK  then (4) else 0
{-# LINE 150 "System/Posix/Files.hsc" #-}
   write_f = if writeOK then (2) else 0
{-# LINE 151 "System/Posix/Files.hsc" #-}
   exec_f  = if execOK  then (1) else 0
{-# LINE 152 "System/Posix/Files.hsc" #-}

-- | Checks for the existence of the file.
--
-- Note: calls @access@.
fileExist :: FilePath -> IO Bool
fileExist name = 
  withFilePath name $ \s -> do
    r <- c_access s (0)
{-# LINE 160 "System/Posix/Files.hsc" #-}
    if (r == 0)
	then return True
	else do err <- getErrno
	        if (err == eNOENT)
		   then return False
		   else throwErrnoPath "fileExist" name

access :: FilePath -> CMode -> IO Bool
access name flags = 
  withFilePath name $ \s -> do
    r <- c_access s (fromIntegral flags)
    if (r == 0)
	then return True
	else do err <- getErrno
	        if (err == eACCES)
		   then return False
		   else throwErrnoPath "fileAccess" name


-- | @getFileStatus path@ calls gets the @FileStatus@ information (user ID,
-- size, access times, etc.) for the file @path@.
--
-- Note: calls @stat@.
getFileStatus :: FilePath -> IO FileStatus
getFileStatus path = do
  fp <- mallocForeignPtrBytes (96) 
{-# LINE 186 "System/Posix/Files.hsc" #-}
  withForeignPtr fp $ \p ->
    withFilePath path $ \s -> 
      throwErrnoPathIfMinus1_ "getFileStatus" path (c_stat s p)
  return (FileStatus fp)

-- | Acts as 'getFileStatus' except when the 'FilePath' refers to a symbolic
-- link. In that case the @FileStatus@ information of the symbolic link itself
-- is returned instead of that of the file it points to.
--
-- Note: calls @lstat@.
getSymbolicLinkStatus :: FilePath -> IO FileStatus
getSymbolicLinkStatus path = do
  fp <- mallocForeignPtrBytes (96) 
{-# LINE 199 "System/Posix/Files.hsc" #-}
  withForeignPtr fp $ \p ->
    withFilePath path $ \s -> 
      throwErrnoPathIfMinus1_ "getSymbolicLinkStatus" path (c_lstat s p)
  return (FileStatus fp)

foreign import ccall unsafe "__hsunix_lstat"
  c_lstat :: CString -> Ptr CStat -> IO CInt

-- | @createNamedPipe fifo mode@
-- creates a new named pipe, @fifo@, with permissions based on
-- @mode@. May fail with 'throwErrnoPathIfMinus1_' if a file named @name@
-- already exists or if the effective user ID of the current process doesn't
-- have permission to create the pipe.
--
-- Note: calls @mkfifo@.
createNamedPipe :: FilePath -> FileMode -> IO ()
createNamedPipe name mode = do
  withFilePath name $ \s -> 
    throwErrnoPathIfMinus1_ "createNamedPipe" name (c_mkfifo s mode)

-- | @createDevice path mode dev@ creates either a regular or a special file
-- depending on the value of @mode@ (and @dev@).  @mode@ will normally be either
-- 'blockSpecialMode' or 'characterSpecialMode'.  May fail with
-- 'throwErrnoPathIfMinus1_' if a file named @name@ already exists or if the
-- effective user ID of the current process doesn't have permission to create
-- the file.
--
-- Note: calls @mknod@.
createDevice :: FilePath -> FileMode -> DeviceID -> IO ()
createDevice path mode dev =
  withFilePath path $ \s ->
    throwErrnoPathIfMinus1_ "createDevice" path (c_mknod s mode dev)

foreign import ccall unsafe "__hsunix_mknod" 
  c_mknod :: CString -> CMode -> CDev -> IO CInt

-- -----------------------------------------------------------------------------
-- Hard links

-- | @createLink old new@ creates a new path, @new@, linked to an existing file,
-- @old@.
--
-- Note: calls @link@.
createLink :: FilePath -> FilePath -> IO ()
createLink name1 name2 =
  withFilePath name1 $ \s1 ->
  withFilePath name2 $ \s2 ->
  throwErrnoPathIfMinus1_ "createLink" name1 (c_link s1 s2)

-- | @removeLink path@ removes the link named @path@.
--
-- Note: calls @unlink@.
removeLink :: FilePath -> IO ()
removeLink name =
  withFilePath name $ \s ->
  throwErrnoPathIfMinus1_ "removeLink" name (c_unlink s)

-- -----------------------------------------------------------------------------
-- Symbolic Links

-- | @createSymbolicLink file1 file2@ creates a symbolic link named @file2@
-- which points to the file @file1@.
--
-- Symbolic links are interpreted at run-time as if the contents of the link
-- had been substituted into the path being followed to find a file or directory.
--
-- Note: calls @symlink@.
createSymbolicLink :: FilePath -> FilePath -> IO ()
createSymbolicLink file1 file2 =
  withFilePath file1 $ \s1 ->
  withFilePath file2 $ \s2 ->
  throwErrnoPathIfMinus1_ "createSymbolicLink" file1 (c_symlink s1 s2)

foreign import ccall unsafe "symlink"
  c_symlink :: CString -> CString -> IO CInt

-- ToDo: should really use SYMLINK_MAX, but not everyone supports it yet,
-- and it seems that the intention is that SYMLINK_MAX is no larger than
-- PATH_MAX.

{-# LINE 283 "System/Posix/Files.hsc" #-}

-- | Reads the @FilePath@ pointed to by the symbolic link and returns it.
--
-- Note: calls @readlink@.
readSymbolicLink :: FilePath -> IO FilePath
readSymbolicLink file =
  allocaArray0 (4096) $ \buf -> do
{-# LINE 290 "System/Posix/Files.hsc" #-}
    withFilePath file $ \s -> do
      len <- throwErrnoPathIfMinus1 "readSymbolicLink" file $ 
	c_readlink s buf (4096)
{-# LINE 293 "System/Posix/Files.hsc" #-}
      peekFilePathLen (buf,fromIntegral len)

foreign import ccall unsafe "readlink"
  c_readlink :: CString -> CString -> CSize -> IO CInt

-- -----------------------------------------------------------------------------
-- Renaming files

-- | @rename old new@ renames a file or directory from @old@ to @new@.
--
-- Note: calls @rename@.
rename :: FilePath -> FilePath -> IO ()
rename name1 name2 =
  withFilePath name1 $ \s1 ->
  withFilePath name2 $ \s2 ->
  throwErrnoPathIfMinus1_ "rename" name1 (c_rename s1 s2)

foreign import ccall unsafe "rename"
   c_rename :: CString -> CString -> IO CInt

-- -----------------------------------------------------------------------------
-- chown()

-- | @setOwnerAndGroup path uid gid@ changes the owner and group of @path@ to
-- @uid@ and @gid@, respectively.
--
-- If @uid@ or @gid@ is specified as -1, then that ID is not changed.
--
-- Note: calls @chown@.
setOwnerAndGroup :: FilePath -> UserID -> GroupID -> IO ()
setOwnerAndGroup name uid gid = do
  withFilePath name $ \s ->
    throwErrnoPathIfMinus1_ "setOwnerAndGroup" name (c_chown s uid gid)

foreign import ccall unsafe "chown"
  c_chown :: CString -> CUid -> CGid -> IO CInt


{-# LINE 331 "System/Posix/Files.hsc" #-}
-- | Acts as 'setOwnerAndGroup' but does not follow symlinks (and thus
-- changes permissions on the link itself).
--
-- Note: calls @lchown@.
setSymbolicLinkOwnerAndGroup :: FilePath -> UserID -> GroupID -> IO ()
setSymbolicLinkOwnerAndGroup name uid gid = do
  withFilePath name $ \s ->
    throwErrnoPathIfMinus1_ "setSymbolicLinkOwnerAndGroup" name
	(c_lchown s uid gid)

foreign import ccall unsafe "lchown"
  c_lchown :: CString -> CUid -> CGid -> IO CInt

{-# LINE 344 "System/Posix/Files.hsc" #-}

-- -----------------------------------------------------------------------------
-- utime()

-- | @setFileTimes path atime mtime@ sets the access and modification times
-- associated with file @path@ to @atime@ and @mtime@, respectively.
--
-- Note: calls @utime@.
setFileTimes :: FilePath -> EpochTime -> EpochTime -> IO ()
setFileTimes name atime mtime = do
  withFilePath name $ \s ->
   allocaBytes (8) $ \p -> do
{-# LINE 356 "System/Posix/Files.hsc" #-}
     ((\hsc_ptr -> pokeByteOff hsc_ptr 0))  p atime
{-# LINE 357 "System/Posix/Files.hsc" #-}
     ((\hsc_ptr -> pokeByteOff hsc_ptr 4)) p mtime
{-# LINE 358 "System/Posix/Files.hsc" #-}
     throwErrnoPathIfMinus1_ "setFileTimes" name (c_utime s p)

-- | @touchFile path@ sets the access and modification times associated with
-- file @path@ to the current time.
--
-- Note: calls @utime@.
touchFile :: FilePath -> IO ()
touchFile name = do
  withFilePath name $ \s ->
   throwErrnoPathIfMinus1_ "touchFile" name (c_utime s nullPtr)

-- -----------------------------------------------------------------------------
-- Setting file sizes

-- | Truncates the file down to the specified length. If the file was larger
-- than the given length before this operation was performed the extra is lost.
--
-- Note: calls @truncate@.
setFileSize :: FilePath -> FileOffset -> IO ()
setFileSize file off = 
  withFilePath file $ \s ->
    throwErrnoPathIfMinus1_ "setFileSize" file (c_truncate s off)

foreign import ccall unsafe "truncate"
  c_truncate :: CString -> COff -> IO CInt

-- -----------------------------------------------------------------------------
-- pathconf()/fpathconf() support

-- | @getPathVar var path@ obtains the dynamic value of the requested
-- configurable file limit or option associated with file or directory @path@.
-- For defined file limits, @getPathVar@ returns the associated
-- value.  For defined file options, the result of @getPathVar@
-- is undefined, but not failure.
--
-- Note: calls @pathconf@.
getPathVar :: FilePath -> PathVar -> IO Limit
getPathVar name v = do
  withFilePath name $ \ nameP -> 
    throwErrnoPathIfMinus1 "getPathVar" name $ 
      c_pathconf nameP (pathVarConst v)

foreign import ccall unsafe "pathconf" 
  c_pathconf :: CString -> CInt -> IO CLong