Class INotify::Notifier
In: lib/rb-inotify/notifier.rb
Parent: Object

Notifier wraps a single instance of inotify. It‘s possible to have more than one instance, but usually unnecessary.

@example

  # Create the notifier
  notifier = INotify::Notifier.new

  # Run this callback whenever the file path/to/foo.txt is read
  notifier.watch("path/to/foo.txt", :access) do
    puts "Foo.txt was accessed!"
  end

  # Watch for any file in the directory being deleted
  # or moved out of the directory.
  notifier.watch("path/to/directory", :delete, :moved_from) do |event|
    # The #name field of the event object contains the name of the affected file
    puts "#{event.name} is no longer in the directory!"
  end

  # Nothing happens until you run the notifier!
  notifier.run

Methods

close   new   process   read_events   run   stop   to_io   watch  

Attributes

fd  [R]  The underlying file descriptor for this notifier. This is a valid OS file descriptor, and can be used as such (except under JRuby — see \{to_io}).

@return [Fixnum]

watchers  [R]  A hash from {Watcher} ids to the instances themselves.

@private @return [{Fixnum => Watcher}]

Public Class methods

Creates a new {Notifier}.

@return [Notifier] @raise [SystemCallError] if inotify failed to initialize for some reason

Public Instance methods

Blocks until there are one or more filesystem events that this notifier has watchers registered for. Once there are events, the appropriate callbacks are called and this function returns.

@see run

Blocks until there are one or more filesystem events that this notifier has watchers registered for. Once there are events, returns their {Event} objects.

@private

Starts the notifier watching for filesystem events. Blocks until \{stop} is called.

@see process

Stop watching for filesystem events. That is, if we‘re in a \{run} loop, exit out as soon as we finish handling the events.

Returns a Ruby IO object wrapping the underlying file descriptor. Since this file descriptor is fully functional (except under JRuby), this IO object can be used in any way a Ruby-created IO object can. This includes passing it to functions like `select`.

Note that this always returns the same IO object. Creating lots of IO objects for the same file descriptor can cause some odd problems.

**This is not supported under JRuby**. JRuby currently doesn‘t use native file descriptors for the IO object, so we can‘t use this file descriptor as a stand-in.

@return [IO] An IO object wrapping the file descriptor @raise [NotImplementedError] if this is being called in JRuby

Watches a file or directory for changes, calling the callback when there are. This is only activated once \{process} or \{run} is called.

**Note that by default, this does not recursively watch subdirectories of the watched directory**. To do so, use the `:recursive` flag.

## Flags

`:access` : A file is accessed (that is, read).

`:attrib` : A file‘s metadata is changed (e.g. permissions, timestamps, etc).

`:close_write` : A file that was opened for writing is closed.

`:close_nowrite` : A file that was not opened for writing is closed.

`:modify` : A file is modified.

`:open` : A file is opened.

### Directory-Specific Flags

These flags only apply when a directory is being watched.

`:moved_from` : A file is moved out of the watched directory.

`:moved_to` : A file is moved into the watched directory.

`:create` : A file is created in the watched directory.

`:delete` : A file is deleted in the watched directory.

`:delete_self` : The watched file or directory itself is deleted.

`:move_self` : The watched file or directory itself is moved.

### Helper Flags

These flags are just combinations of the flags above.

`:close` : Either `:close_write` or `:close_nowrite` is activated.

`:move` : Either `:moved_from` or `:moved_to` is activated.

`:all_events` : Any event above is activated.

### Options Flags

These flags don‘t actually specify events. Instead, they specify options for the watcher.

`:onlydir` : Only watch the path if it‘s a directory.

`:dont_follow` : Don‘t follow symlinks.

`:mask_add` : Add these flags to the pre-existing flags for this path.

`:oneshot` : Only send the event once, then shut down the watcher.

`:recursive` : Recursively watch any subdirectories that are created.

  Note that this is a feature of rb-inotify,
  rather than of inotify itself, which can only watch one level of a directory.
  This means that the {Event#name} field
  will contain only the basename of the modified file.
  When using `:recursive`, {Event#absolute_name} should always be used.

@param path [String] The path to the file or directory @param flags [Array<Symbol>] Which events to watch for @yield [event] A block that will be called

  whenever one of the specified events occur

@yieldparam event [Event] The Event object containing information

  about the event that occured

@return [Watcher] A Watcher set up to watch this path for these events @raise [SystemCallError] if the file or directory can‘t be watched,

  e.g. if the file isn't found, read access is denied,
  or the flags don't contain any events

[Validate]