Haskell: Work with file permissions

Haskell System.Directory module Provides number of functions to work with file/directory permissions. Following table summarizes the functions.

Function	Signature	Description
emptyPermissions	emptyPermissions :: Permissions	Return Permissions instance by clearing all. Prelude System.Directory> emptyPermissions Permissions {readable = False, writable = False, executable = False, searchable = False}
readable	readable :: Permissions -> Bool	Return True, if the Permissions instance has the property readable = True, else False.
writable	writable :: Permissions -> Bool	Return True, if the Permissions instance has the property writable = True, else False.
executable	executable :: Permissions -> Bool	Return True, if the Permissions instance has the property executable = True, else False.
searchable	searchable :: Permissions -> Bool	Return True, if the Permissions instance has the property searchable = True, else False
setOwnerReadable	setOwnerReadable :: Bool -> Permissions -> Permissions	If the Bool argument is True, it sets the readable permission to the owner, else unset.
setOwnerWritable	setOwnerWritable :: Bool -> Permissions -> Permissions	If the Bool argument is True, it sets the writable permission to the owner, else unset.
setOwnerExecutable	setOwnerExecutable :: Bool -> Permissions -> Permissions	If the Bool argument is True, it sets the executable permission to the owner, else unset.
setOwnerSearchable	setOwnerSearchable :: Bool -> Permissions -> Permissions	If the Bool argument is True, it sets the searchable permission to the owner, else unset.
getPermissions	getPermissions :: FilePath -> IO Permissions	Get the permissions of a file (or) directory.
setPermissions	setPermissions :: FilePath -> Permissions -> IO ()	Set permissins to given file.
copyPermissions	copyPermissions :: FilePath -> FilePath -> IO ()	Copy permissions of one file to other.

PermissionUtil.hs

import System.IO
import System.Directory

main = do
    putStrLn "Enter directory (or) file"
    file <- getLine

    permissions <- getPermissions file
    let isReadable = readable permissions
    let isWritable = writable permissions
    let isExecutable = executable permissions
    let isSearchable = searchable permissions

    putStrLn $ "permissions : " ++ (show permissions)
    putStrLn $ "isReadable : " ++ (show isReadable)
    putStrLn $ "isWritable : " ++ (show isWritable)
    putStrLn $ "isExecutable : " ++ (show isExecutable)
    putStrLn $ "isSearchable : " ++ (show isSearchable)

$ runghc PermissionUtil.hs 
Enter directory (or) file
/Users/harikrishna_gurram
permissions : Permissions {readable = True, writable = True, executable = False, searchable = True}
isReadable : True
isWritable : True
isExecutable : False
isSearchable : True
$ 
$ runghc PermissionUtil.hs 
Enter directory (or) file
/usr/bin/java
permissions : Permissions {readable = True, writable = False, executable = True, searchable = False}
isReadable : True
isWritable : False
isExecutable : True
isSearchable : False

Note

getPermissions, setPermissions functions may fail with following errors.

isPermissionError if the user is not permitted to access the permissions; or

isDoesNotExistError if the file or directory does not exist.

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