{-# LINE 1 "libraries/unix/System/Posix/User.hsc" #-}
{-# LANGUAGE Trustworthy, CApiFFI, PatternSynonyms, ViewPatterns #-}
module System.Posix.User (
getRealUserID,
getRealGroupID,
getEffectiveUserID,
getEffectiveGroupID,
getGroups,
getLoginName,
getEffectiveUserName,
groupName,
groupPassword,
groupID,
groupMembers,
pattern GroupEntry,
getGroupEntryForID,
getGroupEntryForName,
getAllGroupEntries,
userName,
userPassword,
userID,
userGroupID,
userGecos,
homeDirectory,
userShell,
pattern UserEntry,
getUserEntryForID,
getUserEntryForName,
getAllUserEntries,
setUserID,
setGroupID,
setEffectiveUserID,
setEffectiveGroupID,
setGroups
) where
import System.Posix.Types
import System.IO.Unsafe (unsafePerformIO)
import Foreign.C
import Foreign.Ptr
import Foreign.Marshal
import Foreign.Storable
import System.Posix.User.Common ( UserEntry, GroupEntry
{-# LINE 70 "libraries/unix/System/Posix/User.hsc" #-}
, unpackUserEntry, unpackGroupEntry, LKUPTYPE(..), CPasswd, CGroup
{-# LINE 72 "libraries/unix/System/Posix/User.hsc" #-}
)
import qualified System.Posix.User.Common as User
{-# LINE 76 "libraries/unix/System/Posix/User.hsc" #-}
{-# LINE 79 "libraries/unix/System/Posix/User.hsc" #-}
import Control.Concurrent.MVar ( MVar, newMVar, withMVar )
import Control.Exception
{-# LINE 82 "libraries/unix/System/Posix/User.hsc" #-}
import Control.Monad
import System.IO.Error
import qualified Data.ByteString.Char8 as C8
{-# LINE 90 "libraries/unix/System/Posix/User.hsc" #-}
{-# LINE 155 "libraries/unix/System/Posix/User.hsc" #-}
{-# LINE 221 "libraries/unix/System/Posix/User.hsc" #-}
pwlock :: MVar ()
pwlock :: MVar ()
pwlock = IO (MVar ()) -> MVar ()
forall a. IO a -> a
unsafePerformIO (IO (MVar ()) -> MVar ()) -> IO (MVar ()) -> MVar ()
forall a b. (a -> b) -> a -> b
$ () -> IO (MVar ())
forall a. a -> IO (MVar a)
newMVar ()
{-# NOINLINE pwlock #-}
lockpw :: LKUPTYPE -> IO a -> IO a
{-# LINE 234 "libraries/unix/System/Posix/User.hsc" #-}
lockpw :: forall a. LKUPTYPE -> IO a -> IO a
lockpw LKUPTYPE
GETONE = IO a -> IO a
forall a. a -> a
id
lockpw LKUPTYPE
GETALL = MVar () -> (() -> IO a) -> IO a
forall a b. MVar a -> (a -> IO b) -> IO b
withMVar MVar ()
pwlock ((() -> IO a) -> IO a) -> (IO a -> () -> IO a) -> IO a -> IO a
forall b c a. (b -> c) -> (a -> b) -> a -> c
. IO a -> () -> IO a
forall a b. a -> b -> a
const
{-# LINE 237 "libraries/unix/System/Posix/User.hsc" #-}
{-# LINE 240 "libraries/unix/System/Posix/User.hsc" #-}
{-# LINE 242 "libraries/unix/System/Posix/User.hsc" #-}
grlock :: MVar ()
grlock :: MVar ()
grlock = IO (MVar ()) -> MVar ()
forall a. IO a -> a
unsafePerformIO (IO (MVar ()) -> MVar ()) -> IO (MVar ()) -> MVar ()
forall a b. (a -> b) -> a -> b
$ () -> IO (MVar ())
forall a. a -> IO (MVar a)
newMVar ()
{-# NOINLINE grlock #-}
lockgr :: LKUPTYPE -> IO a -> IO a
{-# LINE 255 "libraries/unix/System/Posix/User.hsc" #-}
lockgr :: forall a. LKUPTYPE -> IO a -> IO a
lockgr LKUPTYPE
GETONE = IO a -> IO a
forall a. a -> a
id
lockgr LKUPTYPE
GETALL = MVar () -> (() -> IO a) -> IO a
forall a b. MVar a -> (a -> IO b) -> IO b
withMVar MVar ()
grlock ((() -> IO a) -> IO a) -> (IO a -> () -> IO a) -> IO a -> IO a
forall b c a. (b -> c) -> (a -> b) -> a -> c
. IO a -> () -> IO a
forall a b. a -> b -> a
const
{-# LINE 258 "libraries/unix/System/Posix/User.hsc" #-}
{-# LINE 261 "libraries/unix/System/Posix/User.hsc" #-}
getRealUserID :: IO UserID
getRealUserID :: IO UserID
getRealUserID = IO UserID
c_getuid
foreign import ccall unsafe "getuid"
c_getuid :: IO CUid
getRealGroupID :: IO GroupID
getRealGroupID :: IO GroupID
getRealGroupID = IO GroupID
c_getgid
foreign import ccall unsafe "getgid"
c_getgid :: IO CGid
getEffectiveUserID :: IO UserID
getEffectiveUserID :: IO UserID
getEffectiveUserID = IO UserID
c_geteuid
foreign import ccall unsafe "geteuid"
c_geteuid :: IO CUid
getEffectiveGroupID :: IO GroupID
getEffectiveGroupID :: IO GroupID
getEffectiveGroupID = IO GroupID
c_getegid
foreign import ccall unsafe "getegid"
c_getegid :: IO CGid
getGroups :: IO [GroupID]
getGroups :: IO [GroupID]
getGroups = do
ngroups <- CInt -> Ptr GroupID -> IO CInt
c_getgroups CInt
0 Ptr GroupID
forall a. Ptr a
nullPtr
allocaArray (fromIntegral ngroups) $ \Ptr GroupID
arr -> do
String -> IO CInt -> IO ()
forall a. (Eq a, Num a) => String -> IO a -> IO ()
throwErrnoIfMinus1_ String
"getGroups" (CInt -> Ptr GroupID -> IO CInt
c_getgroups CInt
ngroups Ptr GroupID
arr)
groups <- Int -> Ptr GroupID -> IO [GroupID]
forall a. Storable a => Int -> Ptr a -> IO [a]
peekArray (CInt -> Int
forall a b. (Integral a, Num b) => a -> b
fromIntegral CInt
ngroups) Ptr GroupID
arr
return groups
foreign import ccall unsafe "getgroups"
c_getgroups :: CInt -> Ptr CGid -> IO CInt
setGroups :: [GroupID] -> IO ()
setGroups :: [GroupID] -> IO ()
setGroups [GroupID]
groups = do
[GroupID] -> (Int -> Ptr GroupID -> IO ()) -> IO ()
forall a b. Storable a => [a] -> (Int -> Ptr a -> IO b) -> IO b
withArrayLen [GroupID]
groups ((Int -> Ptr GroupID -> IO ()) -> IO ())
-> (Int -> Ptr GroupID -> IO ()) -> IO ()
forall a b. (a -> b) -> a -> b
$ \ Int
ngroups Ptr GroupID
arr ->
String -> IO CInt -> IO ()
forall a. (Eq a, Num a) => String -> IO a -> IO ()
throwErrnoIfMinus1_ String
"setGroups" (CInt -> Ptr GroupID -> IO CInt
c_setgroups (Int -> CInt
forall a b. (Integral a, Num b) => a -> b
fromIntegral Int
ngroups) Ptr GroupID
arr)
foreign import ccall unsafe "setgroups"
c_setgroups :: CInt -> Ptr CGid -> IO CInt
getLoginName :: IO String
getLoginName :: IO String
getLoginName = do
str <- String -> IO (Ptr CChar) -> IO (Ptr CChar)
forall a. String -> IO (Ptr a) -> IO (Ptr a)
throwErrnoIfNull String
"getLoginName" IO (Ptr CChar)
c_getlogin
peekCAString str
foreign import ccall unsafe "getlogin"
c_getlogin :: IO CString
setUserID :: UserID -> IO ()
setUserID :: UserID -> IO ()
setUserID UserID
uid = String -> IO CInt -> IO ()
forall a. (Eq a, Num a) => String -> IO a -> IO ()
throwErrnoIfMinus1_ String
"setUserID" (UserID -> IO CInt
c_setuid UserID
uid)
foreign import ccall unsafe "setuid"
c_setuid :: CUid -> IO CInt
setEffectiveUserID :: UserID -> IO ()
setEffectiveUserID :: UserID -> IO ()
setEffectiveUserID UserID
uid = String -> IO CInt -> IO ()
forall a. (Eq a, Num a) => String -> IO a -> IO ()
throwErrnoIfMinus1_ String
"setEffectiveUserID" (UserID -> IO CInt
c_seteuid UserID
uid)
foreign import ccall unsafe "seteuid"
c_seteuid :: CUid -> IO CInt
setGroupID :: GroupID -> IO ()
setGroupID :: GroupID -> IO ()
setGroupID GroupID
gid = String -> IO CInt -> IO ()
forall a. (Eq a, Num a) => String -> IO a -> IO ()
throwErrnoIfMinus1_ String
"setGroupID" (GroupID -> IO CInt
c_setgid GroupID
gid)
foreign import ccall unsafe "setgid"
c_setgid :: CGid -> IO CInt
setEffectiveGroupID :: GroupID -> IO ()
setEffectiveGroupID :: GroupID -> IO ()
setEffectiveGroupID GroupID
gid =
String -> IO CInt -> IO ()
forall a. (Eq a, Num a) => String -> IO a -> IO ()
throwErrnoIfMinus1_ String
"setEffectiveGroupID" (GroupID -> IO CInt
c_setegid GroupID
gid)
foreign import ccall unsafe "setegid"
c_setegid :: CGid -> IO CInt
getEffectiveUserName :: IO String
getEffectiveUserName :: IO String
getEffectiveUserName = do
euid <- IO UserID
getEffectiveUserID
pw <- getUserEntryForID euid
return (userName pw)
{-# LINE 381 "libraries/unix/System/Posix/User.hsc" #-}
groupName :: GroupEntry -> String
groupName :: GroupEntry -> String
groupName (GroupEntry String
gn String
_ GroupID
_ [String]
_) = String
gn
groupPassword :: GroupEntry -> String
groupPassword :: GroupEntry -> String
groupPassword (GroupEntry String
_ String
gp GroupID
_ [String]
_) = String
gp
groupID :: GroupEntry -> GroupID
groupID :: GroupEntry -> GroupID
groupID (GroupEntry String
_ String
_ GroupID
id' [String]
_) = GroupID
id'
groupMembers :: GroupEntry -> [String]
groupMembers :: GroupEntry -> [String]
groupMembers (GroupEntry String
_ String
_ GroupID
_ [String]
gm) = [String]
gm
pattern GroupEntry :: String
-> String
-> GroupID
-> [String]
-> GroupEntry
pattern $mGroupEntry :: forall {r}.
GroupEntry
-> (String -> String -> GroupID -> [String] -> r)
-> ((# #) -> r)
-> r
$bGroupEntry :: String -> String -> GroupID -> [String] -> GroupEntry
GroupEntry gn gp gi gm <- User.GroupEntry (C8.unpack -> gn) (C8.unpack -> gp) gi (fmap C8.unpack -> gm) where
GroupEntry String
gn String
gp GroupID
gi [String]
gm = ByteString -> ByteString -> GroupID -> [ByteString] -> GroupEntry
User.GroupEntry (String -> ByteString
C8.pack String
gn) (String -> ByteString
C8.pack String
gp) GroupID
gi (String -> ByteString
C8.pack (String -> ByteString) -> [String] -> [ByteString]
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> [String]
gm)
{-# COMPLETE GroupEntry #-}
{-# LINE 426 "libraries/unix/System/Posix/User.hsc" #-}
getGroupEntryForID :: GroupID -> IO GroupEntry
{-# LINE 433 "libraries/unix/System/Posix/User.hsc" #-}
getGroupEntryForID gid = lockgr GETONE $
allocaBytes (32) $ \pgr ->
{-# LINE 435 "libraries/unix/System/Posix/User.hsc" #-}
doubleAllocWhileERANGE "getGroupEntryForID" "group"
grBufSize unpackGroupEntry $ c_getgrgid_r gid pgr
foreign import capi safe "HsUnix.h getgrgid_r"
c_getgrgid_r :: CGid -> Ptr CGroup -> CString
-> CSize -> Ptr (Ptr CGroup) -> IO CInt
{-# LINE 445 "libraries/unix/System/Posix/User.hsc" #-}
getGroupEntryForName :: String -> IO GroupEntry
{-# LINE 452 "libraries/unix/System/Posix/User.hsc" #-}
getGroupEntryForName name = lockgr GETONE $
allocaBytes (32) $ \pgr ->
{-# LINE 454 "libraries/unix/System/Posix/User.hsc" #-}
withCAString name $ \ pstr ->
doubleAllocWhileERANGE "getGroupEntryForName" "group"
grBufSize unpackGroupEntry $ c_getgrnam_r pstr pgr
foreign import capi safe "HsUnix.h getgrnam_r"
c_getgrnam_r :: CString -> Ptr CGroup -> CString
-> CSize -> Ptr (Ptr CGroup) -> IO CInt
{-# LINE 465 "libraries/unix/System/Posix/User.hsc" #-}
getAllGroupEntries :: IO [GroupEntry]
{-# LINE 476 "libraries/unix/System/Posix/User.hsc" #-}
getAllGroupEntries = lockgr GETALL $ bracket_ c_setgrent c_endgrent $ worker []
where
worker accum = do
resetErrno
ppw <- throwErrnoIfNullAndError "getAllGroupEntries" $ c_getgrent
if ppw == nullPtr
then return (reverse accum)
else do thisentry <- unpackGroupEntry ppw
worker (thisentry : accum)
foreign import ccall safe "getgrent" c_getgrent :: IO (Ptr CGroup)
foreign import ccall safe "setgrent" c_setgrent :: IO ()
foreign import ccall safe "endgrent" c_endgrent :: IO ()
{-# LINE 493 "libraries/unix/System/Posix/User.hsc" #-}
{-# LINE 495 "libraries/unix/System/Posix/User.hsc" #-}
grBufSize :: Int
{-# LINE 497 "libraries/unix/System/Posix/User.hsc" #-}
grBufSize = sysconfWithDefault 1024 (69)
{-# LINE 498 "libraries/unix/System/Posix/User.hsc" #-}
{-# LINE 501 "libraries/unix/System/Posix/User.hsc" #-}
{-# LINE 502 "libraries/unix/System/Posix/User.hsc" #-}
{-# LINE 504 "libraries/unix/System/Posix/User.hsc" #-}
userName :: UserEntry -> String
userName :: UserEntry -> String
userName (UserEntry String
n String
_ UserID
_ GroupID
_ String
_ String
_ String
_) = String
n
userPassword :: UserEntry -> String
userPassword :: UserEntry -> String
userPassword (UserEntry String
_ String
p UserID
_ GroupID
_ String
_ String
_ String
_) = String
p
userID :: UserEntry -> UserID
userID :: UserEntry -> UserID
userID (UserEntry String
_ String
_ UserID
id' GroupID
_ String
_ String
_ String
_) = UserID
id'
userGroupID :: UserEntry -> GroupID
userGroupID :: UserEntry -> GroupID
userGroupID (UserEntry String
_ String
_ UserID
_ GroupID
gid String
_ String
_ String
_) = GroupID
gid
userGecos :: UserEntry -> String
userGecos :: UserEntry -> String
userGecos (UserEntry String
_ String
_ UserID
_ GroupID
_ String
ge String
_ String
_) = String
ge
homeDirectory :: UserEntry -> String
homeDirectory :: UserEntry -> String
homeDirectory (UserEntry String
_ String
_ UserID
_ GroupID
_ String
_ String
hd String
_) = String
hd
userShell :: UserEntry -> String
userShell :: UserEntry -> String
userShell (UserEntry String
_ String
_ UserID
_ GroupID
_ String
_ String
_ String
us) = String
us
pattern UserEntry :: String
-> String
-> UserID
-> GroupID
-> String
-> String
-> String
-> UserEntry
pattern $mUserEntry :: forall {r}.
UserEntry
-> (String
-> String -> UserID -> GroupID -> String -> String -> String -> r)
-> ((# #) -> r)
-> r
$bUserEntry :: String
-> String
-> UserID
-> GroupID
-> String
-> String
-> String
-> UserEntry
UserEntry un up ui ugi ug hd us <- User.UserEntry (C8.unpack -> un)
(C8.unpack -> up)
ui
ugi
(C8.unpack -> ug)
(C8.unpack -> hd)
(C8.unpack -> us) where
UserEntry String
un String
up UserID
ui GroupID
ugi String
ug String
hd String
us = ByteString
-> ByteString
-> UserID
-> GroupID
-> ByteString
-> ByteString
-> ByteString
-> UserEntry
User.UserEntry (String -> ByteString
C8.pack String
un)
(String -> ByteString
C8.pack String
up)
UserID
ui
GroupID
ugi
(String -> ByteString
C8.pack String
ug)
(String -> ByteString
C8.pack String
hd)
(String -> ByteString
C8.pack String
us)
{-# COMPLETE UserEntry #-}
getUserEntryForID :: UserID -> IO UserEntry
{-# LINE 561 "libraries/unix/System/Posix/User.hsc" #-}
getUserEntryForID uid = lockpw GETONE $
allocaBytes (48) $ \ppw ->
{-# LINE 563 "libraries/unix/System/Posix/User.hsc" #-}
doubleAllocWhileERANGE "getUserEntryForID" "user"
pwBufSize unpackUserEntry $ c_getpwuid_r uid ppw
foreign import capi safe "HsUnix.h getpwuid_r"
c_getpwuid_r :: CUid -> Ptr CPasswd ->
CString -> CSize -> Ptr (Ptr CPasswd) -> IO CInt
{-# LINE 573 "libraries/unix/System/Posix/User.hsc" #-}
getUserEntryForName :: String -> IO UserEntry
{-# LINE 580 "libraries/unix/System/Posix/User.hsc" #-}
getUserEntryForName name = lockpw GETONE $
allocaBytes (48) $ \ppw ->
{-# LINE 582 "libraries/unix/System/Posix/User.hsc" #-}
withCAString name $ \ pstr ->
doubleAllocWhileERANGE "getUserEntryForName" "user"
pwBufSize unpackUserEntry $ c_getpwnam_r pstr ppw
foreign import capi safe "HsUnix.h getpwnam_r"
c_getpwnam_r :: CString -> Ptr CPasswd
-> CString -> CSize -> Ptr (Ptr CPasswd) -> IO CInt
{-# LINE 593 "libraries/unix/System/Posix/User.hsc" #-}
getAllUserEntries :: IO [UserEntry]
{-# LINE 598 "libraries/unix/System/Posix/User.hsc" #-}
getAllUserEntries = lockpw GETALL $ bracket_ c_setpwent c_endpwent $ worker []
where
worker accum = do
resetErrno
ppw <- throwErrnoIfNullAndError "getAllUserEntries" $ c_getpwent
if ppw == nullPtr
then return (reverse accum)
else do thisentry <- unpackUserEntry ppw
worker (thisentry : accum)
foreign import ccall safe "getpwent" c_getpwent :: IO (Ptr CPasswd)
foreign import ccall safe "setpwent" c_setpwent :: IO ()
foreign import ccall safe "endpwent" c_endpwent :: IO ()
{-# LINE 615 "libraries/unix/System/Posix/User.hsc" #-}
{-# LINE 617 "libraries/unix/System/Posix/User.hsc" #-}
pwBufSize :: Int
{-# LINE 619 "libraries/unix/System/Posix/User.hsc" #-}
pwBufSize = sysconfWithDefault 1024 (70)
{-# LINE 620 "libraries/unix/System/Posix/User.hsc" #-}
{-# LINE 623 "libraries/unix/System/Posix/User.hsc" #-}
{-# LINE 624 "libraries/unix/System/Posix/User.hsc" #-}
{-# LINE 626 "libraries/unix/System/Posix/User.hsc" #-}
foreign import ccall unsafe "sysconf"
c_sysconf :: CInt -> IO CLong
sysconfWithDefault :: Int -> CInt -> Int
sysconfWithDefault :: Int -> CInt -> Int
sysconfWithDefault Int
def CInt
sc =
IO Int -> Int
forall a. IO a -> a
unsafePerformIO (IO Int -> Int) -> IO Int -> Int
forall a b. (a -> b) -> a -> b
$ do v <- (CLong -> Int) -> IO CLong -> IO Int
forall a b. (a -> b) -> IO a -> IO b
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
fmap CLong -> Int
forall a b. (Integral a, Num b) => a -> b
fromIntegral (IO CLong -> IO Int) -> IO CLong -> IO Int
forall a b. (a -> b) -> a -> b
$ CInt -> IO CLong
c_sysconf CInt
sc
return $ if v == (-1) then def else v
{-# LINE 638 "libraries/unix/System/Posix/User.hsc" #-}
{-# LINE 640 "libraries/unix/System/Posix/User.hsc" #-}
doubleAllocWhileERANGE
:: String
-> String
-> Int
-> (Ptr r -> IO a)
-> (Ptr b -> CSize -> Ptr (Ptr r) -> IO CInt)
-> IO a
doubleAllocWhileERANGE :: forall r a b.
String
-> String
-> Int
-> (Ptr r -> IO a)
-> (Ptr b -> CSize -> Ptr (Ptr r) -> IO CInt)
-> IO a
doubleAllocWhileERANGE String
loc String
enttype Int
initlen Ptr r -> IO a
unpack Ptr b -> CSize -> Ptr (Ptr r) -> IO CInt
action =
(Ptr (Ptr r) -> IO a) -> IO a
forall a b. Storable a => (Ptr a -> IO b) -> IO b
alloca ((Ptr (Ptr r) -> IO a) -> IO a) -> (Ptr (Ptr r) -> IO a) -> IO a
forall a b. (a -> b) -> a -> b
$ Int -> Ptr (Ptr r) -> IO a
go Int
initlen
where
go :: Int -> Ptr (Ptr r) -> IO a
go Int
len Ptr (Ptr r)
res = do
r <- Int -> (Ptr b -> IO (Either CInt a)) -> IO (Either CInt a)
forall a b. Int -> (Ptr a -> IO b) -> IO b
allocaBytes Int
len ((Ptr b -> IO (Either CInt a)) -> IO (Either CInt a))
-> (Ptr b -> IO (Either CInt a)) -> IO (Either CInt a)
forall a b. (a -> b) -> a -> b
$ \Ptr b
buf -> do
rc <- Ptr b -> CSize -> Ptr (Ptr r) -> IO CInt
action Ptr b
buf (Int -> CSize
forall a b. (Integral a, Num b) => a -> b
fromIntegral Int
len) Ptr (Ptr r)
res
if rc /= 0
then return (Left rc)
else do p <- peek res
when (p == nullPtr) $ notFoundErr
fmap Right (unpack p)
case r of
Right a
x -> a -> IO a
forall a. a -> IO a
forall (m :: * -> *) a. Monad m => a -> m a
return a
x
Left CInt
rc | CInt -> Errno
Errno CInt
rc Errno -> Errno -> Bool
forall a. Eq a => a -> a -> Bool
== Errno
eRANGE ->
Int -> Ptr (Ptr r) -> IO a
go (Int
2 Int -> Int -> Int
forall a. Num a => a -> a -> a
* Int
len) Ptr (Ptr r)
res
Left CInt
rc ->
IOError -> IO a
forall a. HasCallStack => IOError -> IO a
ioError (String -> Errno -> Maybe Handle -> Maybe String -> IOError
errnoToIOError String
loc (CInt -> Errno
Errno CInt
rc) Maybe Handle
forall a. Maybe a
Nothing Maybe String
forall a. Maybe a
Nothing)
notFoundErr :: IO a
notFoundErr =
IOError -> IO a
forall a. HasCallStack => IOError -> IO a
ioError (IOError -> IO a) -> IOError -> IO a
forall a b. (a -> b) -> a -> b
$ (IOError -> String -> IOError) -> String -> IOError -> IOError
forall a b c. (a -> b -> c) -> b -> a -> c
flip IOError -> String -> IOError
ioeSetErrorString (String
"no such " String -> String -> String
forall a. [a] -> [a] -> [a]
++ String
enttype)
(IOError -> IOError) -> IOError -> IOError
forall a b. (a -> b) -> a -> b
$ IOErrorType -> String -> Maybe Handle -> Maybe String -> IOError
mkIOError IOErrorType
doesNotExistErrorType String
loc Maybe Handle
forall a. Maybe a
Nothing Maybe String
forall a. Maybe a
Nothing
throwErrnoIfNullAndError :: String -> IO (Ptr a) -> IO (Ptr a)
throwErrnoIfNullAndError :: forall a. String -> IO (Ptr a) -> IO (Ptr a)
throwErrnoIfNullAndError String
loc IO (Ptr a)
act = do
rc <- IO (Ptr a)
act
errno <- getErrno
if rc == nullPtr && errno /= eOK
then throwErrno loc
else return rc
{-# LINE 689 "libraries/unix/System/Posix/User.hsc" #-}