extra-1.5.2: Extra functions I use.

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Extra directory functions. Most of these functions provide cleaned up and generalised versions of getDirectoryContents, see listContents for the differences.



withCurrentDirectory :: FilePath -> IO a -> IO a Source

Set the current directory, perform an operation, then change back. Remember that the current directory is a global variable, so calling this function multithreaded is almost certain to go wrong. Avoid changing the current directory if you can.

withTempDir $ \dir -> do writeFile (dir </> "foo.txt") ""; withCurrentDirectory dir $ doesFileExist "foo.txt"

createDirectoryPrivate :: String -> IO () Source

Create a directory with permissions so that only the current user can view it. On Windows this function is equivalent to createDirectory.

listContents :: FilePath -> IO [FilePath] Source

List the files and directories directly within a directory. Each result will be prefixed by the query directory, and the special directories . and .. will be ignored. Intended as a cleaned up version of getDirectoryContents.

withTempDir $ \dir -> do writeFile (dir </> "test.txt") ""; (== [dir </> "test.txt"]) <$> listContents dir
let touch = mapM_ $ \x -> createDirectoryIfMissing True (takeDirectory x) >> writeFile x ""
let listTest op as bs = withTempDir $ \dir -> do touch $ map (dir </>) as; res <- op dir; return $ map (drop (length dir + 1)) res == bs
listTest listContents ["bar.txt","foo/baz.txt","zoo"] ["bar.txt","foo","zoo"]

listFiles :: FilePath -> IO [FilePath] Source

Like listContents, but only returns the files in a directory, not other directories. Each file will be prefixed by the query directory.

listTest listFiles ["bar.txt","foo/baz.txt","zoo"] ["bar.txt","zoo"]

listFilesInside :: (FilePath -> IO Bool) -> FilePath -> IO [FilePath] Source

Like listFilesRecursive, but with a predicate to decide where to recurse into. Typically directories starting with . would be ignored. The initial argument directory will have the test applied to it.

listTest (listFilesInside $ return . not . isPrefixOf "." . takeFileName)
    ["bar.txt","foo" </> "baz.txt",".foo" </> "baz2.txt", "zoo"] ["bar.txt","zoo","foo" </> "baz.txt"]
listTest (listFilesInside $ const $ return False) ["bar.txt"] []

listFilesRecursive :: FilePath -> IO [FilePath] Source

Like listFiles, but goes recursively through all subdirectories. This function will follow symlinks, and if they form a loop, this function will not terminate.

listTest listFilesRecursive ["bar.txt","zoo","foo" </> "baz.txt"] ["bar.txt","zoo","foo" </> "baz.txt"]