dist-install/build/System/Posix/Files/Common.hs

    {-# LINE 1 "libraries/unix/System/Posix/Files/Common.hsc" #-}

    {-# LINE 2 "libraries/unix/System/Posix/Files/Common.hsc" #-}
    {-# LANGUAGE Trustworthy #-}

    {-# LINE 4 "libraries/unix/System/Posix/Files/Common.hsc" #-}
    -----------------------------------------------------------------------------
    -- |
    -- Module      :  System.Posix.Files.Common
    -- 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 29 "libraries/unix/System/Posix/Files/Common.hsc" #-}

    module System.Posix.Files.Common (
        -- * 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
        setFdMode, setFileCreationMask,

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

        -- * Setting file sizes
        setFdSize,

        -- * Changing file ownership
        setFdOwnerAndGroup,

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

        -- * Low level types and functions

    {-# LINE 75 "libraries/unix/System/Posix/Files/Common.hsc" #-}
        CTimeVal(..),
        toCTimeVal,
        c_utimes,

    {-# LINE 79 "libraries/unix/System/Posix/Files/Common.hsc" #-}
        c_lutimes,

    {-# LINE 81 "libraries/unix/System/Posix/Files/Common.hsc" #-}
      ) where

    import System.Posix.Types
    import System.IO.Unsafe
    import Data.Bits

    {-# LINE 92 "libraries/unix/System/Posix/Files/Common.hsc" #-}
    import Data.Int
    import Data.Ratio

    {-# LINE 95 "libraries/unix/System/Posix/Files/Common.hsc" #-}
    import Data.Time.Clock.POSIX (POSIXTime)
    import System.Posix.Internals
    import Foreign.C
    import Foreign.ForeignPtr

    {-# LINE 100 "libraries/unix/System/Posix/Files/Common.hsc" #-}
    import Foreign.Marshal (withArray)

    {-# LINE 102 "libraries/unix/System/Posix/Files/Common.hsc" #-}
    import Foreign.Ptr
    import Foreign.Storable

    -- -----------------------------------------------------------------------------
    -- POSIX file modes

    -- The abstract type 'FileMode', constants and operators for
    -- manipulating the file modes defined by POSIX.

    -- | No permissions.
    nullFileMode :: FileMode
    nullFileMode = 0

    -- | Owner has read permission.
    ownerReadMode :: FileMode
    ownerReadMode = (256)
    {-# LINE 118 "libraries/unix/System/Posix/Files/Common.hsc" #-}

    -- | Owner has write permission.
    ownerWriteMode :: FileMode
    ownerWriteMode = (128)
    {-# LINE 122 "libraries/unix/System/Posix/Files/Common.hsc" #-}

    -- | Owner has execute permission.
    ownerExecuteMode :: FileMode
    ownerExecuteMode = (64)
    {-# LINE 126 "libraries/unix/System/Posix/Files/Common.hsc" #-}

    -- | Group has read permission.
    groupReadMode :: FileMode
    groupReadMode = (32)
    {-# LINE 130 "libraries/unix/System/Posix/Files/Common.hsc" #-}

    -- | Group has write permission.
    groupWriteMode :: FileMode
    groupWriteMode = (16)
    {-# LINE 134 "libraries/unix/System/Posix/Files/Common.hsc" #-}

    -- | Group has execute permission.
    groupExecuteMode :: FileMode
    groupExecuteMode = (8)
    {-# LINE 138 "libraries/unix/System/Posix/Files/Common.hsc" #-}

    -- | Others have read permission.
    otherReadMode :: FileMode
    otherReadMode = (4)
    {-# LINE 142 "libraries/unix/System/Posix/Files/Common.hsc" #-}

    -- | Others have write permission.
    otherWriteMode :: FileMode
    otherWriteMode = (2)
    {-# LINE 146 "libraries/unix/System/Posix/Files/Common.hsc" #-}

    -- | Others have execute permission.
    otherExecuteMode :: FileMode
    otherExecuteMode = (1)
    {-# LINE 150 "libraries/unix/System/Posix/Files/Common.hsc" #-}

    -- | Set user ID on execution.
    setUserIDMode :: FileMode
    setUserIDMode = (2048)
    {-# LINE 154 "libraries/unix/System/Posix/Files/Common.hsc" #-}

    -- | Set group ID on execution.
    setGroupIDMode :: FileMode
    setGroupIDMode = (1024)
    {-# LINE 158 "libraries/unix/System/Posix/Files/Common.hsc" #-}

    -- | Owner, group and others have read and write permission.
    stdFileMode :: FileMode
    stdFileMode = ownerReadMode  .|. ownerWriteMode .|.
                  groupReadMode  .|. groupWriteMode .|.
                  otherReadMode  .|. otherWriteMode

    -- | Owner has read, write and execute permission.
    ownerModes :: FileMode
    ownerModes = (448)
    {-# LINE 168 "libraries/unix/System/Posix/Files/Common.hsc" #-}

    -- | Group has read, write and execute permission.
    groupModes :: FileMode
    groupModes = (56)
    {-# LINE 172 "libraries/unix/System/Posix/Files/Common.hsc" #-}

    -- | Others have read, write and execute permission.
    otherModes :: FileMode
    otherModes = (7)
    {-# LINE 176 "libraries/unix/System/Posix/Files/Common.hsc" #-}

    -- | Owner, group and others have read, write and execute permission.
    accessModes :: FileMode
    accessModes = ownerModes .|. groupModes .|. otherModes

    -- | Combines the two file modes into one that contains modes that appear in
    -- either.
    unionFileModes :: FileMode -> FileMode -> FileMode
    unionFileModes m1 m2 = m1 .|. m2

    -- | Combines two file modes into one that only contains modes that appear in
    -- both.
    intersectFileModes :: FileMode -> FileMode -> FileMode
    intersectFileModes m1 m2 = m1 .&. m2

    fileTypeModes :: FileMode
    fileTypeModes = (61440)
    {-# LINE 193 "libraries/unix/System/Posix/Files/Common.hsc" #-}

    blockSpecialMode :: FileMode
    blockSpecialMode = (24576)
    {-# LINE 196 "libraries/unix/System/Posix/Files/Common.hsc" #-}

    characterSpecialMode :: FileMode
    characterSpecialMode = (8192)
    {-# LINE 199 "libraries/unix/System/Posix/Files/Common.hsc" #-}

    namedPipeMode :: FileMode
    namedPipeMode = (4096)
    {-# LINE 202 "libraries/unix/System/Posix/Files/Common.hsc" #-}

    regularFileMode :: FileMode
    regularFileMode = (32768)
    {-# LINE 205 "libraries/unix/System/Posix/Files/Common.hsc" #-}

    directoryMode :: FileMode
    directoryMode = (16384)
    {-# LINE 208 "libraries/unix/System/Posix/Files/Common.hsc" #-}

    symbolicLinkMode :: FileMode
    symbolicLinkMode = (40960)
    {-# LINE 211 "libraries/unix/System/Posix/Files/Common.hsc" #-}

    socketMode :: FileMode
    socketMode = (49152)
    {-# LINE 214 "libraries/unix/System/Posix/Files/Common.hsc" #-}

    -- | @setFdMode fd mode@ acts like 'setFileMode' but uses a file descriptor
    -- @fd@ instead of a 'FilePath'.
    --
    -- Note: calls @fchmod@.
    setFdMode :: Fd -> FileMode -> IO ()
    setFdMode (Fd fd) m =
      throwErrnoIfMinus1_ "setFdMode" (c_fchmod fd m)

    foreign import ccall unsafe "fchmod"
      c_fchmod :: CInt -> CMode -> IO CInt

    -- | @setFileCreationMask mode@ sets the file mode creation mask to @mode@.
    -- Modes set by this operation are subtracted from files and directories upon
    -- creation. The previous file creation mask is returned.
    --
    -- Note: calls @umask@.
    setFileCreationMask :: FileMode -> IO FileMode
    setFileCreationMask mask = c_umask mask

    -- -----------------------------------------------------------------------------
    -- stat() support

    -- | POSIX defines operations to get information, such as owner, permissions,
    -- size and access times, about a file. This information is represented by the
    -- 'FileStatus' type.
    --
    -- Note: see @chmod@.
    newtype FileStatus = FileStatus (ForeignPtr CStat)

    -- | ID of the device on which this file resides.
    deviceID         :: FileStatus -> DeviceID
    -- | inode number
    fileID           :: FileStatus -> FileID
    -- | File mode (such as permissions).
    fileMode         :: FileStatus -> FileMode
    -- | Number of hard links to this file.
    linkCount        :: FileStatus -> LinkCount
    -- | ID of owner.
    fileOwner        :: FileStatus -> UserID
    -- | ID of group.
    fileGroup        :: FileStatus -> GroupID
    -- | Describes the device that this file represents.
    specialDeviceID  :: FileStatus -> DeviceID
    -- | Size of the file in bytes. If this file is a symbolic link the size is
    -- the length of the pathname it contains.
    fileSize         :: FileStatus -> FileOffset
    -- | Time of last access.
    accessTime       :: FileStatus -> EpochTime
    -- | Time of last access in sub-second resolution.
    accessTimeHiRes  :: FileStatus -> POSIXTime
    -- | Time of last modification.
    modificationTime :: FileStatus -> EpochTime
    -- | Time of last modification in sub-second resolution.
    modificationTimeHiRes :: FileStatus -> POSIXTime
    -- | Time of last status change (i.e. owner, group, link count, mode, etc.).
    statusChangeTime :: FileStatus -> EpochTime
    -- | Time of last status change (i.e. owner, group, link count, mode, etc.) in sub-second resolution.
    statusChangeTimeHiRes :: FileStatus -> POSIXTime

    deviceID (FileStatus stat) =
      unsafePerformIO $ withForeignPtr stat $ ((\hsc_ptr -> peekByteOff hsc_ptr 0))
    {-# LINE 276 "libraries/unix/System/Posix/Files/Common.hsc" #-}
    fileID (FileStatus stat) =
      unsafePerformIO $ withForeignPtr stat $ ((\hsc_ptr -> peekByteOff hsc_ptr 4))
    {-# LINE 278 "libraries/unix/System/Posix/Files/Common.hsc" #-}
    fileMode (FileStatus stat) =
      unsafePerformIO $ withForeignPtr stat $ ((\hsc_ptr -> peekByteOff hsc_ptr 8))
    {-# LINE 280 "libraries/unix/System/Posix/Files/Common.hsc" #-}
    linkCount (FileStatus stat) =
      unsafePerformIO $ withForeignPtr stat $ ((\hsc_ptr -> peekByteOff hsc_ptr 10))
    {-# LINE 282 "libraries/unix/System/Posix/Files/Common.hsc" #-}
    fileOwner (FileStatus stat) =
      unsafePerformIO $ withForeignPtr stat $ ((\hsc_ptr -> peekByteOff hsc_ptr 12))
    {-# LINE 284 "libraries/unix/System/Posix/Files/Common.hsc" #-}
    fileGroup (FileStatus stat) =
      unsafePerformIO $ withForeignPtr stat $ ((\hsc_ptr -> peekByteOff hsc_ptr 16))
    {-# LINE 286 "libraries/unix/System/Posix/Files/Common.hsc" #-}
    specialDeviceID (FileStatus stat) =
      unsafePerformIO $ withForeignPtr stat $ ((\hsc_ptr -> peekByteOff hsc_ptr 20))
    {-# LINE 288 "libraries/unix/System/Posix/Files/Common.hsc" #-}
    fileSize (FileStatus stat) =
      unsafePerformIO $ withForeignPtr stat $ ((\hsc_ptr -> peekByteOff hsc_ptr 72))
    {-# LINE 290 "libraries/unix/System/Posix/Files/Common.hsc" #-}
    accessTime (FileStatus stat) =
      unsafePerformIO $ withForeignPtr stat $ ((\hsc_ptr -> peekByteOff hsc_ptr 24))
    {-# LINE 292 "libraries/unix/System/Posix/Files/Common.hsc" #-}
    modificationTime (FileStatus stat) =
      unsafePerformIO $ withForeignPtr stat $ ((\hsc_ptr -> peekByteOff hsc_ptr 40))
    {-# LINE 294 "libraries/unix/System/Posix/Files/Common.hsc" #-}
    statusChangeTime (FileStatus stat) =
      unsafePerformIO $ withForeignPtr stat $ ((\hsc_ptr -> peekByteOff hsc_ptr 56))
    {-# LINE 296 "libraries/unix/System/Posix/Files/Common.hsc" #-}

    accessTimeHiRes (FileStatus stat) =
      unsafePerformIO $ withForeignPtr stat $ \stat_ptr -> do
        sec  <- ((\hsc_ptr -> peekByteOff hsc_ptr 24)) stat_ptr :: IO EpochTime
    {-# LINE 300 "libraries/unix/System/Posix/Files/Common.hsc" #-}

    {-# LINE 304 "libraries/unix/System/Posix/Files/Common.hsc" #-}
        nsec <- ((\hsc_ptr -> peekByteOff hsc_ptr 32)) stat_ptr :: IO (Int64)
    {-# LINE 305 "libraries/unix/System/Posix/Files/Common.hsc" #-}
        let frac = toInteger nsec % 10^(9::Int)

    {-# LINE 318 "libraries/unix/System/Posix/Files/Common.hsc" #-}
        return $ fromRational $ toRational sec + frac

    modificationTimeHiRes (FileStatus stat) =
      unsafePerformIO $ withForeignPtr stat $ \stat_ptr -> do
        sec  <- ((\hsc_ptr -> peekByteOff hsc_ptr 40)) stat_ptr :: IO EpochTime
    {-# LINE 323 "libraries/unix/System/Posix/Files/Common.hsc" #-}

    {-# LINE 327 "libraries/unix/System/Posix/Files/Common.hsc" #-}
        nsec <- ((\hsc_ptr -> peekByteOff hsc_ptr 48)) stat_ptr :: IO (Int64)
    {-# LINE 328 "libraries/unix/System/Posix/Files/Common.hsc" #-}
        let frac = toInteger nsec % 10^(9::Int)

    {-# LINE 341 "libraries/unix/System/Posix/Files/Common.hsc" #-}
        return $ fromRational $ toRational sec + frac

    statusChangeTimeHiRes (FileStatus stat) =
      unsafePerformIO $ withForeignPtr stat $ \stat_ptr -> do
        sec  <- ((\hsc_ptr -> peekByteOff hsc_ptr 56)) stat_ptr :: IO EpochTime
    {-# LINE 346 "libraries/unix/System/Posix/Files/Common.hsc" #-}

    {-# LINE 350 "libraries/unix/System/Posix/Files/Common.hsc" #-}
        nsec <- ((\hsc_ptr -> peekByteOff hsc_ptr 64)) stat_ptr :: IO (Int64)
    {-# LINE 351 "libraries/unix/System/Posix/Files/Common.hsc" #-}
        let frac = toInteger nsec % 10^(9::Int)

    {-# LINE 364 "libraries/unix/System/Posix/Files/Common.hsc" #-}
        return $ fromRational $ toRational sec + frac

    -- | Checks if this file is a block device.
    isBlockDevice     :: FileStatus -> Bool
    -- | Checks if this file is a character device.
    isCharacterDevice :: FileStatus -> Bool
    -- | Checks if this file is a named pipe device.
    isNamedPipe       :: FileStatus -> Bool
    -- | Checks if this file is a regular file device.
    isRegularFile     :: FileStatus -> Bool
    -- | Checks if this file is a directory device.
    isDirectory       :: FileStatus -> Bool
    -- | Checks if this file is a symbolic link device.
    isSymbolicLink    :: FileStatus -> Bool
    -- | Checks if this file is a socket device.
    isSocket          :: FileStatus -> Bool

    isBlockDevice stat =
      (fileMode stat `intersectFileModes` fileTypeModes) == blockSpecialMode
    isCharacterDevice stat =
      (fileMode stat `intersectFileModes` fileTypeModes) == characterSpecialMode
    isNamedPipe stat =
      (fileMode stat `intersectFileModes` fileTypeModes) == namedPipeMode
    isRegularFile stat =
      (fileMode stat `intersectFileModes` fileTypeModes) == regularFileMode
    isDirectory stat =
      (fileMode stat `intersectFileModes` fileTypeModes) == directoryMode
    isSymbolicLink stat =
      (fileMode stat `intersectFileModes` fileTypeModes) == symbolicLinkMode
    isSocket stat =
      (fileMode stat `intersectFileModes` fileTypeModes) == socketMode

    -- | @getFdStatus fd@ acts as 'getFileStatus' but uses a file descriptor @fd@.
    --
    -- Note: calls @fstat@.
    getFdStatus :: Fd -> IO FileStatus
    getFdStatus (Fd fd) = do
      fp <- mallocForeignPtrBytes (120)
    {-# LINE 402 "libraries/unix/System/Posix/Files/Common.hsc" #-}
      withForeignPtr fp $ \p ->
        throwErrnoIfMinus1_ "getFdStatus" (c_fstat fd p)
      return (FileStatus fp)

    -- -----------------------------------------------------------------------------
    -- Setting file times

    {-# LINE 429 "libraries/unix/System/Posix/Files/Common.hsc" #-}

    {-# LINE 434 "libraries/unix/System/Posix/Files/Common.hsc" #-}

    {-# LINE 439 "libraries/unix/System/Posix/Files/Common.hsc" #-}

    data CTimeVal = CTimeVal CLong CLong

    instance Storable CTimeVal where
        sizeOf    _ = (16)
    {-# LINE 444 "libraries/unix/System/Posix/Files/Common.hsc" #-}
        alignment _ = alignment (undefined :: CInt)
        poke p (CTimeVal sec usec) = do
            ((\hsc_ptr -> pokeByteOff hsc_ptr 0)) p sec
    {-# LINE 447 "libraries/unix/System/Posix/Files/Common.hsc" #-}
            ((\hsc_ptr -> pokeByteOff hsc_ptr 8)) p usec
    {-# LINE 448 "libraries/unix/System/Posix/Files/Common.hsc" #-}
        peek p = do
            sec  <- (\hsc_ptr -> peekByteOff hsc_ptr 0) p
    {-# LINE 450 "libraries/unix/System/Posix/Files/Common.hsc" #-}
            usec <- (\hsc_ptr -> peekByteOff hsc_ptr 8) p
    {-# LINE 451 "libraries/unix/System/Posix/Files/Common.hsc" #-}
            return $ CTimeVal sec usec

    toCTimeVal :: POSIXTime -> CTimeVal
    toCTimeVal t = CTimeVal sec (truncate $ 10^(6::Int) * frac)
      where
        (sec, frac) = if (frac' < 0) then (sec' - 1, frac' + 1) else (sec', frac')
        (sec', frac') = properFraction $ toRational t

    foreign import ccall unsafe "utimes"
        c_utimes :: CString -> Ptr CTimeVal -> IO CInt

    {-# LINE 463 "libraries/unix/System/Posix/Files/Common.hsc" #-}
    foreign import ccall unsafe "lutimes"
        c_lutimes :: CString -> Ptr CTimeVal -> IO CInt

    {-# LINE 466 "libraries/unix/System/Posix/Files/Common.hsc" #-}

    {-# LINE 468 "libraries/unix/System/Posix/Files/Common.hsc" #-}
    foreign import ccall unsafe "futimes"
        c_futimes :: CInt -> Ptr CTimeVal -> IO CInt

    {-# LINE 471 "libraries/unix/System/Posix/Files/Common.hsc" #-}

    -- | Like 'setFileTimesHiRes' but uses a file descriptor instead of a path.
    -- This operation is not supported on all platforms. On these platforms,
    -- this function will raise an exception.
    --
    -- Note: calls @futimens@ or @futimes@.
    --
    -- /Since: 2.7.0.0/
    setFdTimesHiRes :: Fd -> POSIXTime -> POSIXTime -> IO ()

    {-# LINE 485 "libraries/unix/System/Posix/Files/Common.hsc" #-}
    setFdTimesHiRes (Fd fd) atime mtime =
      withArray [toCTimeVal atime, toCTimeVal mtime] $ \times ->
        throwErrnoIfMinus1_ "setFdTimesHiRes" (c_futimes fd times)

    {-# LINE 492 "libraries/unix/System/Posix/Files/Common.hsc" #-}

    -- | Like 'touchFile' but uses a file descriptor instead of a path.
    -- This operation is not supported on all platforms. On these platforms,
    -- this function will raise an exception.
    --
    -- Note: calls @futimes@.
    --
    -- /Since: 2.7.0.0/
    touchFd :: Fd -> IO ()

    {-# LINE 502 "libraries/unix/System/Posix/Files/Common.hsc" #-}
    touchFd (Fd fd) =
      throwErrnoIfMinus1_ "touchFd" (c_futimes fd nullPtr)

    {-# LINE 508 "libraries/unix/System/Posix/Files/Common.hsc" #-}

    -- -----------------------------------------------------------------------------
    -- fchown()

    -- | Acts as 'setOwnerAndGroup' but uses a file descriptor instead of a
    -- 'FilePath'.
    --
    -- Note: calls @fchown@.
    setFdOwnerAndGroup :: Fd -> UserID -> GroupID -> IO ()
    setFdOwnerAndGroup (Fd fd) uid gid =
      throwErrnoIfMinus1_ "setFdOwnerAndGroup" (c_fchown fd uid gid)

    foreign import ccall unsafe "fchown"
      c_fchown :: CInt -> CUid -> CGid -> IO CInt

    -- -----------------------------------------------------------------------------
    -- ftruncate()

    -- | Acts as 'setFileSize' but uses a file descriptor instead of a 'FilePath'.
    --
    -- Note: calls @ftruncate@.
    setFdSize :: Fd -> FileOffset -> IO ()
    setFdSize (Fd fd) off =
      throwErrnoIfMinus1_ "setFdSize" (c_ftruncate fd off)

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

    data PathVar
      = FileSizeBits                  {- _PC_FILESIZEBITS     -}
      | LinkLimit                     {- _PC_LINK_MAX         -}
      | InputLineLimit                {- _PC_MAX_CANON        -}
      | InputQueueLimit               {- _PC_MAX_INPUT        -}
      | FileNameLimit                 {- _PC_NAME_MAX         -}
      | PathNameLimit                 {- _PC_PATH_MAX         -}
      | PipeBufferLimit               {- _PC_PIPE_BUF         -}
                                      -- These are described as optional in POSIX:
                                      {- _PC_ALLOC_SIZE_MIN     -}
                                      {- _PC_REC_INCR_XFER_SIZE -}
                                      {- _PC_REC_MAX_XFER_SIZE  -}
                                      {- _PC_REC_MIN_XFER_SIZE  -}
                                      {- _PC_REC_XFER_ALIGN     -}
      | SymbolicLinkLimit             {- _PC_SYMLINK_MAX      -}
      | SetOwnerAndGroupIsRestricted  {- _PC_CHOWN_RESTRICTED -}
      | FileNamesAreNotTruncated      {- _PC_NO_TRUNC         -}
      | VDisableChar                  {- _PC_VDISABLE         -}
      | AsyncIOAvailable              {- _PC_ASYNC_IO         -}
      | PrioIOAvailable               {- _PC_PRIO_IO          -}
      | SyncIOAvailable               {- _PC_SYNC_IO          -}

    pathVarConst :: PathVar -> CInt
    pathVarConst v = case v of
            LinkLimit                       -> (1)
    {-# LINE 561 "libraries/unix/System/Posix/Files/Common.hsc" #-}
            InputLineLimit                  -> (2)
    {-# LINE 562 "libraries/unix/System/Posix/Files/Common.hsc" #-}
            InputQueueLimit                 -> (3)
    {-# LINE 563 "libraries/unix/System/Posix/Files/Common.hsc" #-}
            FileNameLimit                   -> (4)
    {-# LINE 564 "libraries/unix/System/Posix/Files/Common.hsc" #-}
            PathNameLimit                   -> (5)
    {-# LINE 565 "libraries/unix/System/Posix/Files/Common.hsc" #-}
            PipeBufferLimit                 -> (6)
    {-# LINE 566 "libraries/unix/System/Posix/Files/Common.hsc" #-}
            SetOwnerAndGroupIsRestricted    -> (7)
    {-# LINE 567 "libraries/unix/System/Posix/Files/Common.hsc" #-}
            FileNamesAreNotTruncated        -> (8)
    {-# LINE 568 "libraries/unix/System/Posix/Files/Common.hsc" #-}
            VDisableChar                    -> (9)
    {-# LINE 569 "libraries/unix/System/Posix/Files/Common.hsc" #-}

    {-# LINE 571 "libraries/unix/System/Posix/Files/Common.hsc" #-}
            SyncIOAvailable         -> (55)
    {-# LINE 572 "libraries/unix/System/Posix/Files/Common.hsc" #-}

    {-# LINE 575 "libraries/unix/System/Posix/Files/Common.hsc" #-}

    {-# LINE 577 "libraries/unix/System/Posix/Files/Common.hsc" #-}
            AsyncIOAvailable        -> (53)
    {-# LINE 578 "libraries/unix/System/Posix/Files/Common.hsc" #-}

    {-# LINE 581 "libraries/unix/System/Posix/Files/Common.hsc" #-}

    {-# LINE 583 "libraries/unix/System/Posix/Files/Common.hsc" #-}
            PrioIOAvailable         -> (54)
    {-# LINE 584 "libraries/unix/System/Posix/Files/Common.hsc" #-}

    {-# LINE 587 "libraries/unix/System/Posix/Files/Common.hsc" #-}

    {-# LINE 589 "libraries/unix/System/Posix/Files/Common.hsc" #-}
            FileSizeBits            -> (12)
    {-# LINE 590 "libraries/unix/System/Posix/Files/Common.hsc" #-}

    {-# LINE 593 "libraries/unix/System/Posix/Files/Common.hsc" #-}

    {-# LINE 595 "libraries/unix/System/Posix/Files/Common.hsc" #-}
            SymbolicLinkLimit       -> (18)
    {-# LINE 596 "libraries/unix/System/Posix/Files/Common.hsc" #-}

    {-# LINE 599 "libraries/unix/System/Posix/Files/Common.hsc" #-}

    -- | @getFdPathVar var fd@ obtains the dynamic value of the requested
    -- configurable file limit or option associated with the file or directory
    -- attached to the open channel @fd@. For defined file limits, @getFdPathVar@
    -- returns the associated value.  For defined file options, the result of
    -- @getFdPathVar@ is undefined, but not failure.
    --
    -- Note: calls @fpathconf@.
    getFdPathVar :: Fd -> PathVar -> IO Limit
    getFdPathVar (Fd fd) v =
        throwErrnoIfMinus1 "getFdPathVar" $
          c_fpathconf fd (pathVarConst v)

    foreign import ccall unsafe "fpathconf"
      c_fpathconf :: CInt -> CInt -> IO CLong