Safe Haskell	None
Language	Haskell2010

System.FSNotify

Contents

Events
Starting/Stopping
Configuration
Lower level
Watching

Description

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

Synopsis

data Event
- = 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 {
  - eventPath :: FilePath
  - eventTime :: UTCTime
  - eventIsDirectory :: EventIsDirectory
  }
- | CloseWrite {
  - eventPath :: FilePath
  - eventTime :: UTCTime
  - eventIsDirectory :: EventIsDirectory
  }
- | Unknown {
  - eventPath :: FilePath
  - eventTime :: UTCTime
  - eventIsDirectory :: EventIsDirectory
  - eventString :: String
  }
data EventIsDirectory
- = IsFile
- | IsDirectory
type EventChannel = Chan Event
type Action = Event -> IO ()
type ActionPredicate = Event -> Bool
data WatchManager
withManager :: (WatchManager -> IO a) -> IO a
startManager :: IO WatchManager
stopManager :: WatchManager -> IO ()
defaultConfig :: WatchConfig
data WatchConfig
confWatchMode :: WatchConfig -> WatchMode
confThreadingMode :: WatchConfig -> ThreadingMode
confOnHandlerException :: WatchConfig -> SomeException -> IO ()
data WatchMode
- = WatchModePoll {
  - watchModePollInterval :: Int
  }
- | WatchModeOS
data ThreadingMode
- = SingleThread
- | ThreadPerWatch
- | ThreadPerEvent
withManagerConf :: WatchConfig -> (WatchManager -> IO a) -> IO a
startManagerConf :: WatchConfig -> IO WatchManager
type StopListening = IO ()
watchDir :: WatchManager -> FilePath -> ActionPredicate -> Action -> IO StopListening
watchDirChan :: WatchManager -> FilePath -> ActionPredicate -> EventChannel -> IO StopListening
watchTree :: WatchManager -> FilePath -> ActionPredicate -> Action -> IO StopListening
watchTreeChan :: WatchManager -> FilePath -> ActionPredicate -> EventChannel -> IO StopListening

Events

data Event Source #

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

Instances

Instances details

Show Event Source #
Instance details Defined in System.FSNotify.Types Methods showsPrec :: Int -> Event -> ShowS # show :: Event -> String # showList :: [Event] -> ShowS #
Eq Event Source #
Instance details Defined in System.FSNotify.Types Methods (==) :: Event -> Event -> Bool # (/=) :: Event -> Event -> Bool #

data EventIsDirectory Source #

Constructors

IsFile
IsDirectory

Instances

Instances details

Show EventIsDirectory Source #
Instance details Defined in System.FSNotify.Types Methods showsPrec :: Int -> EventIsDirectory -> ShowS # show :: EventIsDirectory -> String # showList :: [EventIsDirectory] -> ShowS #
Eq EventIsDirectory Source #
Instance details Defined in System.FSNotify.Types Methods (==) :: EventIsDirectory -> EventIsDirectory -> Bool # (/=) :: EventIsDirectory -> EventIsDirectory -> Bool #

type EventChannel = Chan Event Source #

type Action = Event -> IO () Source #

An action to be performed in response to an event.

type ActionPredicate = Event -> Bool Source #

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

Starting/Stopping

data WatchManager Source #

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

withManager :: (WatchManager -> IO a) -> IO a Source #

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

startManager :: IO WatchManager Source #

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.

stopManager :: WatchManager -> IO () Source #

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

Configuration

defaultConfig :: WatchConfig Source #

Default configuration

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

data WatchConfig Source #

Watch configuration.

confWatchMode :: WatchConfig -> WatchMode Source #

Watch mode to use.

confThreadingMode :: WatchConfig -> ThreadingMode Source #

Threading mode to use.

confOnHandlerException :: WatchConfig -> SomeException -> IO () Source #

Called when a handler throws an exception.

data WatchMode Source #

Method of watching for changes.

Constructors

WatchModePoll
Fields 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.

data ThreadingMode Source #

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

withManagerConf :: WatchConfig -> (WatchManager -> IO a) -> IO a Source #

Like withManager, but configurable.

startManagerConf :: WatchConfig -> IO WatchManager Source #

Like startManager, but configurable.

type StopListening = IO () Source #

An action that cancels a watching/listening job.

Watching

watchDir :: WatchManager -> FilePath -> ActionPredicate -> Action -> IO StopListening Source #

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.

watchDirChan :: WatchManager -> FilePath -> ActionPredicate -> EventChannel -> IO StopListening Source #

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.

watchTree :: WatchManager -> FilePath -> ActionPredicate -> Action -> IO StopListening Source #

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.

watchTreeChan :: WatchManager -> FilePath -> ActionPredicate -> EventChannel -> IO StopListening Source #

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.