/fssm

The File System State Monitor keeps track of the state of any number of paths and will fire events when said state changes (create/update/delete). FSSM supports using FSEvents on MacOS, Inotify on GNU/Linux, and polling anywhere else.

Primary LanguageRubyMIT LicenseMIT

FSSM project status

Monitor API

There are three ways you can run the monitor.

  1. call monitor with a path parameter, and define callbacks in a block
  2. call monitor with a block to configure multiple paths and callbacks
  3. create a monitor object and run each step manually

Monitor with path

This form watches one path, and enters the run loop automatically. The first parameter is the path to watch, and the second parameter is an optional glob pattern or array of glob patterns that a file must match in order to trigger a callback. The default glob, if ommitted, is '**/*'.

FSSM.monitor('/some/directory/', '**/*') do
  update {|base, relative|}
  delete {|base, relative|}
  create {|base, relative|}
end

Monitor with block

This form watches one or more paths, and enters the run loop automatically. The glob configuration call can be ommitted, and defaults to '**/*'.

FSSM.monitor do
  path '/some/directory/' do
    glob '**/*.yml'

    update {|base, relative|}
    delete {|base, relative|}
    create {|base, relative|}
  end

  path '/some/other/directory/' do
    update {|base, relative|}
    delete {|base, relative|}
    create {|base, relative|}
  end
end

Monitor object

This form doesn't enter the run loop automatically.

monitor = FSSM::Monitor.new

monitor.path '/some/directory/' do
  update {|base, relative|}
  delete {|base, relative|}
  create {|base, relative|}
end

monitor.run

Monitoring directories

By default, FSSM monitors changes in files only. To enable monitoring of files and directories, pass option directories => true in a hash to the monitor. Please note that this may not work as expected in all backends. For example:

FSSM::Monitor.new(:directories => true)
FSSM.monitor(dir, file_glob, :directories => true)

When directories are monitored, there's an additional third argument to the callbacks. Instead of

FSSM.monitor('/some/directory/', '**/*') do
  update {|base, relative|}
  delete {|base, relative|}
  create {|base, relative|}
end

you get this:

FSSM.monitor('/some/directory/', '**/*', :directories => true) do
  update {|base, relative, type|}
  delete {|base, relative, type|}
  create {|base, relative, type|}
end

The value of type argument is either :file or :directory.