Modulefsnotify-0.4.4.0Haskell2010

System.FSNotify

This library does not currently report changes made to directories, only files within watched directories.

Minimal example:

{-# LANGUAGE OverloadedStrings #-} -- for FilePath literals

import System.FSNotify
import Control.Concurrent (threadDelay)
import Control.Monad (forever)

main =
  withManager $ \mgr -> do
    -- start a watching job (in the background)
    watchDir
      mgr          -- manager
      "."          -- directory to watch
      (const True) -- predicate
      print        -- action

    -- sleep forever (until interrupted)
    forever $ threadDelay 1000000

10 types
13 values

Packagefsnotify-0.4.4.0
Exports23
LanguageHaskell2010
LicenceBSD-3-Clause
SourceFSNotify.hs

Events

5 declarations

datadata Event

A file event reported by a file watcher. Each event contains the canonical path for the file and a timestamp guaranteed to be after the event occurred (timestamps represent current time when FSEvents receives it from the OS and/or platform-specific Haskell modules).

Constructors

Added
- eventPath :: FilePath
- eventTime :: UTCTime
- eventIsDirectory :: EventIsDirectory
Modified
- eventPath :: FilePath
- eventTime :: UTCTime
- eventIsDirectory :: EventIsDirectory
ModifiedAttributes
- eventPath :: FilePath
- eventTime :: UTCTime
- eventIsDirectory :: EventIsDirectory
Removed
- eventPath :: FilePath
- eventTime :: UTCTime
- eventIsDirectory :: EventIsDirectory
WatchedDirectoryRemoved
Note: Linux-only
- eventPath :: FilePath
- eventTime :: UTCTime
- eventIsDirectory :: EventIsDirectory
CloseWrite
Note: Linux-only
- eventPath :: FilePath
- eventTime :: UTCTime
- eventIsDirectory :: EventIsDirectory
Unknown
Note: Linux-only
- eventPath :: FilePath
- eventTime :: UTCTime
- eventIsDirectory :: EventIsDirectory
- eventString :: String

Instances2Eq, Show

Eq EventDefined in fsnotify-0.4.4.0 · System.FSNotify.Types
Show EventDefined in fsnotify-0.4.4.0 · System.FSNotify.Types

datadata EventIsDirectory

IsFile IsDirectory

Instances2Eq, Show

Eq EventIsDirectoryDefined in fsnotify-0.4.4.0 · System.FSNotify.Types
Show EventIsDirectoryDefined in fsnotify-0.4.4.0 · System.FSNotify.Types

typetype EventChannel = Chan Event

typetype Action = Event -> IO ()

An action to be performed in response to an event.

typetype ActionPredicate = Event -> Bool

A predicate used to determine whether to act on an event.

Starting/Stopping

4 declarations

datadata WatchManager

Watch manager. You need one in order to create watching jobs.

valuewithManager :: (WatchManager -> IO a) -> IO a

Perform an IO action with a WatchManager in place. Tear down the WatchManager after the action is complete.

valuestartManager :: IO WatchManager

Start a file watch manager. Directories can only be watched when they are managed by a started watch manager. When finished watching. you must release resources via stopManager. It is preferrable if possible to use withManager to handle this automatically.

valuestopManager :: WatchManager -> IO ()

Stop a file watch manager. Stopping a watch manager will immediately stop watching for files and free resources.

Configuration

7 declarations

valuedefaultConfig :: WatchConfig

Default configuration

Uses OS watch mode (if possible) and single thread.

datadata WatchConfig

Watch configuration.

valueconfWatchMode :: WatchConfig -> WatchMode

Watch mode to use.

valueconfThreadingMode :: WatchConfig -> ThreadingMode

Threading mode to use.

valueconfOnHandlerException :: WatchConfig -> SomeException -> IO ()

Called when a handler throws an exception.

datadata WatchMode

Method of watching for changes.

Constructors

WatchModePoll
- watchModePollInterval :: Int
  Polling interval in microseconds.
WatchModeOS
Use OS-specific mechanisms to be notified of changes (inotify on Linux, FSEvents on OSX, etc.). Not currently available on e.g. *BSD and Wasm/WASI.

datadata ThreadingMode

Constructors

SingleThread
Use a single thread for the entire Manager. Event handler callbacks will run sequentially.
ThreadPerWatch
Use a single thread for each watch (i.e. each call to watchDir, watchTree, etc.). Callbacks within a watch will run sequentially but callbacks from different watches may be interleaved.
ThreadPerEvent
Launch a separate thread for every event handler.

Lower level

3 declarations

valuewithManagerConf :: WatchConfig -> (WatchManager -> IO a) -> IO a

Like withManager, but configurable.

valuestartManagerConf :: WatchConfig -> IO WatchManager

Like startManager, but configurable.

typetype StopListening = IO ()

An action that cancels a watching/listening job.

Watching

4 declarations

valuewatchDir

:: WatchManager
-> FilePath
-> ActionPredicate
-> Action
-> IO StopListening

Watch the immediate contents of a directory by committing an Action for each event. Watching the immediate contents of a directory will only report events associated with files within the specified directory, and not files within its subdirectories.

valuewatchDirChan

:: WatchManager
-> FilePath
-> ActionPredicate
-> EventChannel
-> IO StopListening

Watch the immediate contents of a directory by streaming events to a Chan. Watching the immediate contents of a directory will only report events associated with files within the specified directory, and not files within its subdirectories.

valuewatchTree

:: WatchManager
-> FilePath
-> ActionPredicate
-> Action
-> IO StopListening

Watch all the contents of a directory by committing an Action for each event. Watching all the contents of a directory will report events associated with files within the specified directory and its subdirectories.

valuewatchTreeChan

:: WatchManager
-> FilePath
-> ActionPredicate
-> EventChannel
-> IO StopListening

Watch all the contents of a directory by streaming events to a Chan. Watching all the contents of a directory will report events associated with files within the specified directory and its subdirectories.