filemanip/System/FilePath/Find.hs

360 lines
8.4 KiB
Haskell

{-# OPTIONS_GHC -fglasgow-exts #-}
module System.FilePath.Find (
FileInfo(..)
, FileType(..)
, FindClause
, FilterPredicate
, RecursionPredicate
, find
, findWithHandler
, fold
, foldWithHandler
, filePath
, fileStatus
, depth
, fileInfo
, always
, extension
, directory
, fileName
, fileType
, deviceID
, fileID
, fileOwner
, fileGroup
, fileSize
, linkCount
, specialDeviceID
, fileMode
, filePerms
, anyPerms
, accessTime
, modificationTime
, statusChangeTime
, linkTarget
, (~~?)
, (/~?)
, (==?)
, (/=?)
, (>?)
, (<?)
, (>=?)
, (<=?)
, (&&?)
, (||?)
, (.&.?)
) where
import Control.Monad (foldM, forM, liftM, liftM2)
import Control.Monad.Fix (MonadFix)
import Control.Monad.State (State(..), evalState)
import Data.Bits (Bits, (.&.))
import Data.List (sort)
import System.Directory (getDirectoryContents)
import System.FilePath ((</>), takeDirectory, takeExtension, takeFileName)
import System.FilePath.GlobPattern (GlobPattern, (~~), (/~))
import System.IO (hPutStrLn, stderr)
import System.IO.Unsafe (unsafeInterleaveIO, unsafePerformIO)
import qualified Control.Exception as E
import qualified System.Posix.Files as F
import qualified System.Posix.Types as T
data FileInfo = FileInfo
{
infoPath :: FilePath
, infoDepth :: Int
, infoStatus :: F.FileStatus
}
mkFI :: FilePath -> Int -> F.FileStatus -> FileInfo
mkFI = FileInfo
newtype FindClause a = FI { runFI :: State FileInfo a }
deriving (Functor, Monad, MonadFix)
evalFI :: FindClause a
-> FilePath
-> Int
-> F.FileStatus
-> a
evalFI m p d s = evalState (runFI m) (mkFI p d s)
mkFindClause :: (FileInfo -> (a, FileInfo)) -> FindClause a
mkFindClause = FI . State
fileInfo :: FindClause FileInfo
fileInfo = mkFindClause $ \st -> (st, st)
filePath :: FindClause FilePath
filePath = infoPath `liftM` fileInfo
depth :: FindClause Int
depth = infoDepth `liftM` fileInfo
fileStatus :: FindClause F.FileStatus
fileStatus = infoStatus `liftM` fileInfo
type FilterPredicate = FindClause Bool
type RecursionPredicate = FindClause Bool
getDirContents :: FilePath -> IO [FilePath]
getDirContents dir = (sort . filter goodName) `liftM` getDirectoryContents dir
where goodName "." = False
goodName ".." = False
goodName _ = True
findWithHandler :: (FilePath -> E.Exception -> IO [FilePath])
-> RecursionPredicate
-> FilterPredicate
-> FilePath
-> IO [FilePath]
findWithHandler errHandler recurse filter path =
E.handle (errHandler path) $ F.getSymbolicLinkStatus path >>= visit path 0
where visit path depth st =
if F.isDirectory st && evalFI recurse path depth st
then unsafeInterleaveIO (traverse path (succ depth) st)
else filterPath path depth st []
traverse dir depth dirSt = do
names <- E.catch (getDirContents dir) (errHandler dir)
filteredPaths <- forM names $ \name -> do
let path = dir </> name
unsafeInterleaveIO $ E.handle (errHandler path)
(F.getSymbolicLinkStatus path >>= visit path depth)
filterPath dir depth dirSt (concat filteredPaths)
filterPath path depth st result =
return $ if evalFI filter path depth st
then path:result
else result
find :: RecursionPredicate
-> FilterPredicate
-> FilePath
-> IO [FilePath]
find = findWithHandler warnOnError
where warnOnError path err =
hPutStrLn stderr (path ++ ": " ++ show err) >> return []
foldWithHandler :: (FilePath -> a -> E.Exception -> IO a)
-> RecursionPredicate
-> (a -> FileInfo -> a)
-> a
-> FilePath
-> IO a
foldWithHandler errHandler recurse f state path =
E.handle (errHandler path state) $
F.getSymbolicLinkStatus path >>= visit state path 0
where visit state path depth st =
if F.isDirectory st && evalFI recurse path depth st
then traverse state path (succ depth) st
else return (f state (mkFI path depth st))
traverse state dir depth dirSt = E.handle (errHandler dir state) $
getDirContents dir >>=
flip foldM (f state (mkFI dir depth dirSt)) (\state name ->
E.handle (errHandler dir state) $
let path = dir </> name
in F.getSymbolicLinkStatus path >>= visit state path depth)
fold :: RecursionPredicate
-> (a -> FileInfo -> a)
-> a
-> FilePath
-> IO a
fold = foldWithHandler warnOnError
where warnOnError path a err =
hPutStrLn stderr (path ++ ": " ++ show err) >> return a
always :: FindClause Bool
always = return True
extension :: FindClause FilePath
extension = takeExtension `liftM` filePath
fileName :: FindClause FilePath
fileName = takeFileName `liftM` filePath
directory :: FindClause FilePath
directory = takeDirectory `liftM` filePath
linkTarget :: FindClause (Maybe FilePath)
linkTarget = do
path <- filePath
st <- fileStatus
return $ if F.isSymbolicLink st
then unsafePerformIO $ E.handle (const (return Nothing))
(Just `liftM` F.readSymbolicLink path)
else Nothing
data FileType = BlockDevice
| CharacterDevice
| NamedPipe
| RegularFile
| Directory
| SymbolicLink
| Socket
| Unknown
deriving (Eq, Ord, Show)
fileType :: FindClause FileType
fileType = fType `liftM` fileStatus
where fType st | F.isBlockDevice st = BlockDevice
fType st | F.isCharacterDevice st = CharacterDevice
fType st | F.isNamedPipe st = NamedPipe
fType st | F.isRegularFile st = RegularFile
fType st | F.isDirectory st = Directory
fType st | F.isSymbolicLink st = SymbolicLink
fType st | F.isSocket st = Socket
fType _ = Unknown
deviceID :: FindClause T.DeviceID
deviceID = F.deviceID `liftM` fileStatus
fileID :: FindClause T.FileID
fileID = F.fileID `liftM` fileStatus
fileOwner :: FindClause T.UserID
fileOwner = F.fileOwner `liftM` fileStatus
fileGroup :: FindClause T.GroupID
fileGroup = F.fileGroup `liftM` fileStatus
fileSize :: FindClause T.FileOffset
fileSize = F.fileSize `liftM` fileStatus
linkCount :: FindClause T.LinkCount
linkCount = F.linkCount `liftM` fileStatus
specialDeviceID :: FindClause T.DeviceID
specialDeviceID = F.specialDeviceID `liftM` fileStatus
fileMode :: FindClause T.FileMode
fileMode = F.fileMode `liftM` fileStatus
filePerms :: FindClause T.FileMode
filePerms = (.&. 0777) `liftM` fileMode
anyPerms :: T.FileMode
-> FindClause Bool
anyPerms m = filePerms >>= \p -> return (p .&. m /= 0)
accessTime :: FindClause T.EpochTime
accessTime = F.accessTime `liftM` fileStatus
modificationTime :: FindClause T.EpochTime
modificationTime = F.modificationTime `liftM` fileStatus
statusChangeTime :: FindClause T.EpochTime
statusChangeTime = F.statusChangeTime `liftM` fileStatus
liftOp :: Monad m => (a -> b -> c) -> m a -> b -> m c
liftOp f a b = a >>= \a' -> return (f a' b)
(~~?) :: FindClause FilePath
-> GlobPattern
-> FindClause Bool
(~~?) = liftOp (~~)
infix 4 ~~?
(/~?) :: FindClause FilePath
-> GlobPattern
-> FindClause Bool
(/~?) = liftOp (/~)
infix 4 /~?
(==?) :: Eq a => FindClause a
-> a
-> FindClause Bool
(==?) = liftOp (==)
infix 4 ==?
(/=?) :: Eq a => FindClause a
-> a
-> FindClause Bool
(/=?) = liftOp (/=)
infix 4 /=?
(>?) :: Ord a => FindClause a
-> a
-> FindClause Bool
(>?) = liftOp (>)
infix 4 >?
(<?) :: Ord a => FindClause a
-> a
-> FindClause Bool
(<?) = liftOp (<)
infix 4 <?
(.&.?) :: Bits a => FindClause a
-> a
-> FindClause a
(.&.?) = liftOp (.&.)
infixl 7 .&.?
(>=?) :: Ord a => FindClause a
-> a
-> FindClause Bool
(>=?) = liftOp (>=)
infix 4 >=?
(<=?) :: Ord a => FindClause a
-> a
-> FindClause Bool
(<=?) = liftOp (<=)
infix 4 <=?
(&&?) :: FindClause Bool
-> FindClause Bool
-> FindClause Bool
(&&?) = liftM2 (&&)
infixr 3 &&?
(||?) :: FindClause Bool
-> FindClause Bool
-> FindClause Bool
(||?) = liftM2 (||)
infixr 2 ||?