System/Posix/Internals.hs

   1 {-# OPTIONS_GHC -fno-implicit-prelude #-}
   2
   3 -----------------------------------------------------------------------------
   4 -- |
   5 -- Module      :  System.Posix.Internals
   6 -- Copyright   :  (c) The University of Glasgow, 1992-2002
   7 -- License     :  see libraries/base/LICENSE
   8 --
   9 -- Maintainer  :  cvs-ghc@haskell.org
  10 -- Stability   :  internal
  11 -- Portability :  non-portable (requires POSIX)
  12 --
  13 -- POSIX support layer for the standard libraries.
  14 -- This library is built on *every* platform, including Win32.
  15 --
  16 -- Non-posix compliant in order to support the following features:
  17 --      * S_ISSOCK (no sockets in POSIX)
  18 --
  19 -----------------------------------------------------------------------------
  20
  21 -- #hide
  22 module System.Posix.Internals where
  23
  24 #include "HsBaseConfig.h"
  25
  26 import Control.Monad
  27 import System.Posix.Types
  28
  29 import Foreign
  30 import Foreign.C
  31
  32 import Data.Bits
  33 import Data.Maybe
  34
  35 #if __GLASGOW_HASKELL__
  36 import GHC.Base
  37 import GHC.Num
  38 import GHC.Real
  39 import GHC.IOBase
  40 #elif __HUGS__
  41 import Hugs.Prelude (IOException(..), IOErrorType(..))
  42 import Hugs.IO (IOMode(..))
  43 #else
  44 import System.IO
  45 #endif
  46
  47 #ifdef __HUGS__
  48 {-# CFILES cbits/PrelIOUtils.c cbits/dirUtils.c cbits/consUtils.c #-}
  49 #endif
  50
  51 -- ---------------------------------------------------------------------------
  52 -- Types
  53
  54 type CDir       = ()
  55 type CDirent    = ()
  56 type CFLock     = ()
  57 type CGroup     = ()
  58 type CLconv     = ()
  59 type CPasswd    = ()
  60 type CSigaction = ()
  61 type CSigset    = ()
  62 type CStat      = ()
  63 type CTermios   = ()
  64 type CTm        = ()
  65 type CTms       = ()
  66 type CUtimbuf   = ()
  67 type CUtsname   = ()
  68
  69 #ifndef __GLASGOW_HASKELL__
  70 type FD = CInt
  71 #endif
  72
  73 -- ---------------------------------------------------------------------------
  74 -- stat()-related stuff
  75
  76 fdFileSize :: FD -> IO Integer
  77 fdFileSize fd =
  78   allocaBytes sizeof_stat $ \ p_stat -> do
  79     throwErrnoIfMinus1Retry "fileSize" $
  80         c_fstat fd p_stat
  81     c_mode <- st_mode p_stat :: IO CMode
  82     if not (s_isreg c_mode)
  83         then return (-1)
  84         else do
  85     c_size <- st_size p_stat :: IO COff
  86     return (fromIntegral c_size)
  87
  88 data FDType  = Directory | Stream | RegularFile | RawDevice
  89                deriving (Eq)
  90
  91 fileType :: FilePath -> IO FDType
  92 fileType file =
  93   allocaBytes sizeof_stat $ \ p_stat -> do
  94   withCString file $ \p_file -> do
  95     throwErrnoIfMinus1Retry "fileType" $
  96       c_stat p_file p_stat
  97     statGetType p_stat
  98
  99 -- NOTE: On Win32 platforms, this will only work with file descriptors
 100 -- referring to file handles. i.e., it'll fail for socket FDs.
 101 fdType :: FD -> IO FDType
 102 fdType fd =
 103   allocaBytes sizeof_stat $ \ p_stat -> do
 104     throwErrnoIfMinus1Retry "fdType" $
 105         c_fstat fd p_stat
 106     statGetType p_stat
 107
 108 statGetType p_stat = do
 109   c_mode <- st_mode p_stat :: IO CMode
 110   case () of
 111       _ | s_isdir c_mode        -> return Directory
 112         | s_isfifo c_mode || s_issock c_mode || s_ischr  c_mode
 113                                 -> return Stream
 114         | s_isreg c_mode        -> return RegularFile
 115          -- Q: map char devices to RawDevice too?
 116         | s_isblk c_mode        -> return RawDevice
 117         | otherwise             -> ioError ioe_unknownfiletype
 118
 119
 120 ioe_unknownfiletype = IOError Nothing UnsupportedOperation "fdType"
 121                         "unknown file type" Nothing
 122
 123 #if __GLASGOW_HASKELL__ && (defined(mingw32_HOST_OS) || defined(__MINGW32__))
 124 closeFd :: Bool -> CInt -> IO CInt
 125 closeFd isStream fd
 126   | isStream  = c_closesocket fd
 127   | otherwise = c_close fd
 128
 129 foreign import stdcall unsafe "HsBase.h closesocket"
 130    c_closesocket :: CInt -> IO CInt
 131 #endif
 132
 133 fdGetMode :: FD -> IO IOMode
 134 fdGetMode fd = do
 135 #if defined(mingw32_HOST_OS) || defined(__MINGW32__)
 136     -- We don't have a way of finding out which flags are set on FDs
 137     -- on Windows, so make a handle that thinks that anything goes.
 138     let flags = o_RDWR
 139 #else
 140     flags <- throwErrnoIfMinus1Retry "fdGetMode"
 141                 (c_fcntl_read fd const_f_getfl)
 142 #endif
 143     let
 144        wH  = (flags .&. o_WRONLY) /= 0
 145        aH  = (flags .&. o_APPEND) /= 0
 146        rwH = (flags .&. o_RDWR) /= 0
 147
 148        mode
 149          | wH && aH  = AppendMode
 150          | wH        = WriteMode
 151          | rwH       = ReadWriteMode
 152          | otherwise = ReadMode
 153
 154     return mode
 155
 156 -- ---------------------------------------------------------------------------
 157 -- Terminal-related stuff
 158
 159 fdIsTTY :: FD -> IO Bool
 160 fdIsTTY fd = c_isatty fd >>= return.toBool
 161
 162 #if defined(HTYPE_TCFLAG_T)
 163
 164 setEcho :: FD -> Bool -> IO ()
 165 setEcho fd on = do
 166   tcSetAttr fd $ \ p_tios -> do
 167     c_lflag <- c_lflag p_tios :: IO CTcflag
 168     let new_c_lflag
 169          | on        = c_lflag .|. fromIntegral const_echo
 170          | otherwise = c_lflag .&. complement (fromIntegral const_echo)
 171     poke_c_lflag p_tios (new_c_lflag :: CTcflag)
 172
 173 getEcho :: FD -> IO Bool
 174 getEcho fd = do
 175   tcSetAttr fd $ \ p_tios -> do
 176     c_lflag <- c_lflag p_tios :: IO CTcflag
 177     return ((c_lflag .&. fromIntegral const_echo) /= 0)
 178
 179 setCooked :: FD -> Bool -> IO ()
 180 setCooked fd cooked =
 181   tcSetAttr fd $ \ p_tios -> do
 182
 183     -- turn on/off ICANON
 184     c_lflag <- c_lflag p_tios :: IO CTcflag
 185     let new_c_lflag | cooked    = c_lflag .|. (fromIntegral const_icanon)
 186                     | otherwise = c_lflag .&. complement (fromIntegral const_icanon)
 187     poke_c_lflag p_tios (new_c_lflag :: CTcflag)
 188
 189     -- set VMIN & VTIME to 1/0 respectively
 190     when (not cooked) $ do
 191             c_cc <- ptr_c_cc p_tios
 192             let vmin  = (c_cc `plusPtr` (fromIntegral const_vmin))  :: Ptr Word8
 193                 vtime = (c_cc `plusPtr` (fromIntegral const_vtime)) :: Ptr Word8
 194             poke vmin  1
 195             poke vtime 0
 196
 197 tcSetAttr :: FD -> (Ptr CTermios -> IO a) -> IO a
 198 tcSetAttr fd fun = do
 199      allocaBytes sizeof_termios  $ \p_tios -> do
 200         throwErrnoIfMinus1Retry "tcSetAttr"
 201            (c_tcgetattr fd p_tios)
 202
 203 #ifdef __GLASGOW_HASKELL__
 204         -- Save a copy of termios, if this is a standard file descriptor.
 205         -- These terminal settings are restored in hs_exit().
 206         when (fd <= 2) $ do
 207           p <- get_saved_termios fd
 208           when (p == nullPtr) $ do
 209              saved_tios <- mallocBytes sizeof_termios
 210              copyBytes saved_tios p_tios sizeof_termios
 211              set_saved_termios fd saved_tios
 212 #endif
 213
 214         -- tcsetattr() when invoked by a background process causes the process
 215         -- to be sent SIGTTOU regardless of whether the process has TOSTOP set
 216         -- in its terminal flags (try it...).  This function provides a
 217         -- wrapper which temporarily blocks SIGTTOU around the call, making it
 218         -- transparent.
 219         allocaBytes sizeof_sigset_t $ \ p_sigset -> do
 220         allocaBytes sizeof_sigset_t $ \ p_old_sigset -> do
 221              c_sigemptyset p_sigset
 222              c_sigaddset   p_sigset const_sigttou
 223              c_sigprocmask const_sig_block p_sigset p_old_sigset
 224              r <- fun p_tios  -- do the business
 225              throwErrnoIfMinus1Retry_ "tcSetAttr" $
 226                  c_tcsetattr fd const_tcsanow p_tios
 227              c_sigprocmask const_sig_setmask p_old_sigset nullPtr
 228              return r
 229
 230 #ifdef __GLASGOW_HASKELL__
 231 foreign import ccall unsafe "HsBase.h __hscore_get_saved_termios"
 232    get_saved_termios :: CInt -> IO (Ptr CTermios)
 233
 234 foreign import ccall unsafe "HsBase.h __hscore_set_saved_termios"
 235    set_saved_termios :: CInt -> (Ptr CTermios) -> IO ()
 236 #endif
 237
 238 #else
 239
 240 -- 'raw' mode for Win32 means turn off 'line input' (=> buffering and
 241 -- character translation for the console.) The Win32 API for doing
 242 -- this is GetConsoleMode(), which also requires echoing to be disabled
 243 -- when turning off 'line input' processing. Notice that turning off
 244 -- 'line input' implies enter/return is reported as '\r' (and it won't
 245 -- report that character until another character is input..odd.) This
 246 -- latter feature doesn't sit too well with IO actions like IO.hGetLine..
 247 -- consider yourself warned.
 248 setCooked :: FD -> Bool -> IO ()
 249 setCooked fd cooked = do
 250   x <- set_console_buffering fd (if cooked then 1 else 0)
 251   if (x /= 0)
 252    then ioError (ioe_unk_error "setCooked" "failed to set buffering")
 253    else return ()
 254
 255 ioe_unk_error loc msg
 256  = IOError Nothing OtherError loc msg Nothing
 257
 258 -- Note: echoing goes hand in hand with enabling 'line input' / raw-ness
 259 -- for Win32 consoles, hence setEcho ends up being the inverse of setCooked.
 260 setEcho :: FD -> Bool -> IO ()
 261 setEcho fd on = do
 262   x <- set_console_echo fd (if on then 1 else 0)
 263   if (x /= 0)
 264    then ioError (ioe_unk_error "setEcho" "failed to set echoing")
 265    else return ()
 266
 267 getEcho :: FD -> IO Bool
 268 getEcho fd = do
 269   r <- get_console_echo fd
 270   if (r == (-1))
 271    then ioError (ioe_unk_error "getEcho" "failed to get echoing")
 272    else return (r == 1)
 273
 274 foreign import ccall unsafe "consUtils.h set_console_buffering__"
 275    set_console_buffering :: CInt -> CInt -> IO CInt
 276
 277 foreign import ccall unsafe "consUtils.h set_console_echo__"
 278    set_console_echo :: CInt -> CInt -> IO CInt
 279
 280 foreign import ccall unsafe "consUtils.h get_console_echo__"
 281    get_console_echo :: CInt -> IO CInt
 282
 283 #endif
 284
 285 -- ---------------------------------------------------------------------------
 286 -- Turning on non-blocking for a file descriptor
 287
 288 #if !defined(mingw32_HOST_OS) && !defined(__MINGW32__)
 289
 290 setNonBlockingFD fd = do
 291   flags <- throwErrnoIfMinus1Retry "setNonBlockingFD"
 292                  (c_fcntl_read fd const_f_getfl)
 293   -- An error when setting O_NONBLOCK isn't fatal: on some systems
 294   -- there are certain file handles on which this will fail (eg. /dev/null
 295   -- on FreeBSD) so we throw away the return code from fcntl_write.
 296   unless (testBit flags (fromIntegral o_NONBLOCK)) $ do
 297     c_fcntl_write fd const_f_setfl (fromIntegral (flags .|. o_NONBLOCK))
 298     return ()
 299 #else
 300
 301 -- bogus defns for win32
 302 setNonBlockingFD fd = return ()
 303
 304 #endif
 305
 306 -- -----------------------------------------------------------------------------
 307 -- foreign imports
 308
 309 foreign import ccall unsafe "HsBase.h access"
 310    c_access :: CString -> CInt -> IO CInt
 311
 312 foreign import ccall unsafe "HsBase.h chmod"
 313    c_chmod :: CString -> CMode -> IO CInt
 314
 315 foreign import ccall unsafe "HsBase.h chdir"
 316    c_chdir :: CString -> IO CInt
 317
 318 foreign import ccall unsafe "HsBase.h close"
 319    c_close :: CInt -> IO CInt
 320
 321 foreign import ccall unsafe "HsBase.h closedir"
 322    c_closedir :: Ptr CDir -> IO CInt
 323
 324 foreign import ccall unsafe "HsBase.h creat"
 325    c_creat :: CString -> CMode -> IO CInt
 326
 327 foreign import ccall unsafe "HsBase.h dup"
 328    c_dup :: CInt -> IO CInt
 329
 330 foreign import ccall unsafe "HsBase.h dup2"
 331    c_dup2 :: CInt -> CInt -> IO CInt
 332
 333 foreign import ccall unsafe "HsBase.h __hscore_fstat"
 334    c_fstat :: CInt -> Ptr CStat -> IO CInt
 335
 336 foreign import ccall unsafe "HsBase.h getcwd"
 337    c_getcwd   :: Ptr CChar -> CSize -> IO (Ptr CChar)
 338
 339 foreign import ccall unsafe "HsBase.h isatty"
 340    c_isatty :: CInt -> IO CInt
 341
 342 foreign import ccall unsafe "HsBase.h __hscore_lseek"
 343    c_lseek :: CInt -> COff -> CInt -> IO COff
 344
 345 foreign import ccall unsafe "HsBase.h __hscore_lstat"
 346    lstat :: CString -> Ptr CStat -> IO CInt
 347
 348 foreign import ccall unsafe "HsBase.h __hscore_open"
 349    c_open :: CString -> CInt -> CMode -> IO CInt
 350
 351 foreign import ccall unsafe "HsBase.h opendir"
 352    c_opendir :: CString  -> IO (Ptr CDir)
 353
 354 foreign import ccall unsafe "HsBase.h __hscore_mkdir"
 355    mkdir :: CString -> CInt -> IO CInt
 356
 357 foreign import ccall unsafe "HsBase.h read"
 358    c_read :: CInt -> Ptr CChar -> CSize -> IO CSsize
 359
 360 foreign import ccall unsafe "dirUtils.h __hscore_renameFile"
 361    c_rename :: CString -> CString -> IO CInt
 362
 363 foreign import ccall unsafe "HsBase.h rewinddir"
 364    c_rewinddir :: Ptr CDir -> IO ()
 365
 366 foreign import ccall unsafe "HsBase.h rmdir"
 367    c_rmdir :: CString -> IO CInt
 368
 369 foreign import ccall unsafe "HsBase.h __hscore_stat"
 370    c_stat :: CString -> Ptr CStat -> IO CInt
 371
 372 foreign import ccall unsafe "HsBase.h umask"
 373    c_umask :: CMode -> IO CMode
 374
 375 foreign import ccall unsafe "HsBase.h write"
 376    c_write :: CInt -> Ptr CChar -> CSize -> IO CSsize
 377
 378 foreign import ccall unsafe "HsBase.h __hscore_ftruncate"
 379    c_ftruncate :: CInt -> COff -> IO CInt
 380
 381 foreign import ccall unsafe "HsBase.h unlink"
 382    c_unlink :: CString -> IO CInt
 383
 384 foreign import ccall unsafe "HsBase.h getpid"
 385    c_getpid :: IO CPid
 386
 387 #if !defined(mingw32_HOST_OS) && !defined(__MINGW32__)
 388 foreign import ccall unsafe "HsBase.h fcntl"
 389    c_fcntl_read  :: CInt -> CInt -> IO CInt
 390
 391 foreign import ccall unsafe "HsBase.h fcntl"
 392    c_fcntl_write :: CInt -> CInt -> CLong -> IO CInt
 393
 394 foreign import ccall unsafe "HsBase.h fcntl"
 395    c_fcntl_lock  :: CInt -> CInt -> Ptr CFLock -> IO CInt
 396
 397 foreign import ccall unsafe "HsBase.h fork"
 398    c_fork :: IO CPid
 399
 400 foreign import ccall unsafe "HsBase.h link"
 401    c_link :: CString -> CString -> IO CInt
 402
 403 foreign import ccall unsafe "HsBase.h mkfifo"
 404    c_mkfifo :: CString -> CMode -> IO CInt
 405
 406 foreign import ccall unsafe "HsBase.h pipe"
 407    c_pipe :: Ptr CInt -> IO CInt
 408
 409 foreign import ccall unsafe "HsBase.h __hscore_sigemptyset"
 410    c_sigemptyset :: Ptr CSigset -> IO CInt
 411
 412 foreign import ccall unsafe "HsBase.h __hscore_sigaddset"
 413    c_sigaddset :: Ptr CSigset -> CInt -> IO CInt
 414
 415 foreign import ccall unsafe "HsBase.h sigprocmask"
 416    c_sigprocmask :: CInt -> Ptr CSigset -> Ptr CSigset -> IO CInt
 417
 418 foreign import ccall unsafe "HsBase.h tcgetattr"
 419    c_tcgetattr :: CInt -> Ptr CTermios -> IO CInt
 420
 421 foreign import ccall unsafe "HsBase.h tcsetattr"
 422    c_tcsetattr :: CInt -> CInt -> Ptr CTermios -> IO CInt
 423
 424 foreign import ccall unsafe "HsBase.h utime"
 425    c_utime :: CString -> Ptr CUtimbuf -> IO CInt
 426
 427 foreign import ccall unsafe "HsBase.h waitpid"
 428    c_waitpid :: CPid -> Ptr CInt -> CInt -> IO CPid
 429 #endif
 430
 431 -- traversing directories
 432 foreign import ccall unsafe "dirUtils.h __hscore_readdir"
 433   readdir  :: Ptr CDir -> Ptr (Ptr CDirent) -> IO CInt
 434
 435 foreign import ccall unsafe "HsBase.h __hscore_free_dirent"
 436   freeDirEnt  :: Ptr CDirent -> IO ()
 437
 438 foreign import ccall unsafe "HsBase.h __hscore_end_of_dir"
 439   end_of_dir :: CInt
 440
 441 foreign import ccall unsafe "HsBase.h __hscore_d_name"
 442   d_name :: Ptr CDirent -> IO CString
 443
 444 -- POSIX flags only:
 445 foreign import ccall unsafe "HsBase.h __hscore_o_rdonly" o_RDONLY :: CInt
 446 foreign import ccall unsafe "HsBase.h __hscore_o_wronly" o_WRONLY :: CInt
 447 foreign import ccall unsafe "HsBase.h __hscore_o_rdwr"   o_RDWR   :: CInt
 448 foreign import ccall unsafe "HsBase.h __hscore_o_append" o_APPEND :: CInt
 449 foreign import ccall unsafe "HsBase.h __hscore_o_creat"  o_CREAT  :: CInt
 450 foreign import ccall unsafe "HsBase.h __hscore_o_excl"   o_EXCL   :: CInt
 451 foreign import ccall unsafe "HsBase.h __hscore_o_trunc"  o_TRUNC  :: CInt
 452
 453 -- non-POSIX flags.
 454 foreign import ccall unsafe "HsBase.h __hscore_o_noctty"   o_NOCTTY   :: CInt
 455 foreign import ccall unsafe "HsBase.h __hscore_o_nonblock" o_NONBLOCK :: CInt
 456 foreign import ccall unsafe "HsBase.h __hscore_o_binary"   o_BINARY   :: CInt
 457
 458 foreign import ccall unsafe "HsBase.h __hscore_s_isreg"  c_s_isreg  :: CMode -> CInt
 459 foreign import ccall unsafe "HsBase.h __hscore_s_ischr"  c_s_ischr  :: CMode -> CInt
 460 foreign import ccall unsafe "HsBase.h __hscore_s_isblk"  c_s_isblk  :: CMode -> CInt
 461 foreign import ccall unsafe "HsBase.h __hscore_s_isdir"  c_s_isdir  :: CMode -> CInt
 462 foreign import ccall unsafe "HsBase.h __hscore_s_isfifo" c_s_isfifo :: CMode -> CInt
 463
 464 s_isreg  :: CMode -> Bool
 465 s_isreg cm = c_s_isreg cm /= 0
 466 s_ischr  :: CMode -> Bool
 467 s_ischr cm = c_s_ischr cm /= 0
 468 s_isblk  :: CMode -> Bool
 469 s_isblk cm = c_s_isblk cm /= 0
 470 s_isdir  :: CMode -> Bool
 471 s_isdir cm = c_s_isdir cm /= 0
 472 s_isfifo :: CMode -> Bool
 473 s_isfifo cm = c_s_isfifo cm /= 0
 474
 475 foreign import ccall unsafe "HsBase.h __hscore_sizeof_stat" sizeof_stat :: Int
 476 foreign import ccall unsafe "HsBase.h __hscore_st_mtime" st_mtime :: Ptr CStat -> IO CTime
 477 foreign import ccall unsafe "HsBase.h __hscore_st_size" st_size :: Ptr CStat -> IO COff
 478 foreign import ccall unsafe "HsBase.h __hscore_st_mode" st_mode :: Ptr CStat -> IO CMode
 479
 480 foreign import ccall unsafe "HsBase.h __hscore_echo"         const_echo :: CInt
 481 foreign import ccall unsafe "HsBase.h __hscore_tcsanow"      const_tcsanow :: CInt
 482 foreign import ccall unsafe "HsBase.h __hscore_icanon"       const_icanon :: CInt
 483 foreign import ccall unsafe "HsBase.h __hscore_vmin"         const_vmin   :: CInt
 484 foreign import ccall unsafe "HsBase.h __hscore_vtime"        const_vtime  :: CInt
 485 foreign import ccall unsafe "HsBase.h __hscore_sigttou"      const_sigttou :: CInt
 486 foreign import ccall unsafe "HsBase.h __hscore_sig_block"    const_sig_block :: CInt
 487 foreign import ccall unsafe "HsBase.h __hscore_sig_setmask"  const_sig_setmask :: CInt
 488 foreign import ccall unsafe "HsBase.h __hscore_f_getfl"      const_f_getfl :: CInt
 489 foreign import ccall unsafe "HsBase.h __hscore_f_setfl"      const_f_setfl :: CInt
 490
 491 #if defined(HTYPE_TCFLAG_T)
 492 foreign import ccall unsafe "HsBase.h __hscore_sizeof_termios"  sizeof_termios :: Int
 493 foreign import ccall unsafe "HsBase.h __hscore_sizeof_sigset_t" sizeof_sigset_t :: Int
 494
 495 foreign import ccall unsafe "HsBase.h __hscore_lflag" c_lflag :: Ptr CTermios -> IO CTcflag
 496 foreign import ccall unsafe "HsBase.h __hscore_poke_lflag" poke_c_lflag :: Ptr CTermios -> CTcflag -> IO ()
 497 foreign import ccall unsafe "HsBase.h __hscore_ptr_c_cc" ptr_c_cc  :: Ptr CTermios -> IO (Ptr Word8)
 498 #endif
 499
 500 #if !defined(mingw32_HOST_OS) && !defined(__MINGW32__)
 501 foreign import ccall unsafe "HsBase.h __hscore_s_issock" c_s_issock :: CMode -> CInt
 502 s_issock :: CMode -> Bool
 503 s_issock cmode = c_s_issock cmode /= 0
 504 #else
 505 s_issock :: CMode -> Bool
 506 s_issock cmode = False
 507 #endif