Guard is a command line tool to easily handle events on files modifications (FSEvent / Inotify / Polling support).
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Guard is a command line tool that easily handle events on files modifications.

If you have any questions please join us on our Google group or on #guard (



Ryan Bates made a Railscast on Guard, you can view it here:


Install the gem:

$ gem install guard

Or add it to your Gemfile (inside the development group):

gem 'guard'

and install it via Bundler:

$ bundle install

Generate an empty Guardfile with:

$ guard init

You may optionally place a .Guardfile in your home directory to use it across multiple projects. Also note that if a .guard.rb is found in your home directory, it will be appended to the Guardfile.

Add the guards you need to your Guardfile (see the existing guards below).

On Mac OS X

Install the rb-fsevent gem for FSEvent support:

$ gem install rb-fsevent

You have two possibilities:

Use the growl_notify gem (recommended):

$ gem install growl_notify

Use the growlnotify (cli tool for growl) + the growl gem.

$ brew install growlnotify
$ gem install growl

And add them to your Gemfile:

gem 'rb-fsevent'
gem 'growl_notify' # or gem 'growl'

The difference between growl and growl_notify is that growl_notify uses AppleScript to display a message, whereas growl uses the growlnotify command. In general the AppleScript approach is preferred, but you may also use the older growl gem. Have a look at the Guard Wiki for more information.

On Linux

Install the rb-inotify gem for inotify support:

$ gem install rb-inotify

Install the libnotify gem if you want visual notification support:

$ gem install libnotify

And add them to your Gemfile:

gem 'rb-inotify'
gem 'libnotify'

On Windows

Install the rb-fchange gem for Directory Change Notification support:

$ gem install rb-fchange

Install the win32console gem if you want colors in your terminal:

$ gem install win32console

Install the rb-notifu gem if you want visual notification support:

$ gem install rb-notifu

And add them to your Gemfile:

gem 'rb-fchange'
gem 'rb-notifu'
gem 'win32console'


Just launch Guard inside your Ruby / Rails project with:

$ guard [start]

or if you use Bundler, to run the Guard executable specific to your bundle:

$ bundle exec guard [start]

Guard will look for a Guardfile in your current directory. If it does not find one, it will look in your $HOME directory for a .Guardfile.

Command line options

-c/--clear option

Shell can be cleared after each change:

$ guard --clear
$ guard -c # shortcut

-n/--notify option

Notifications (growl/libnotify) can be disabled:

$ guard --notify false
$ guard -n f # shortcut

Notifications can also be disabled globally by setting a GUARD_NOTIFY environment variable to false

-g/--group option

Only certain guards groups can be run (see the Guardfile DSL below for creating groups):

$ guard --group group_name another_group_name
$ guard -g group_name another_group_name # shortcut

-d/--debug option

Guard can be run in debug mode:

$ guard --debug
$ guard -d # shortcut

-w/--watchdir option

Guard can watch in any directory (instead of the current directory):

$ guard --watchdir ~/your/fancy/project
$ guard -w ~/your/fancy/project # shortcut

-G/--guardfile option

Guard can use a Guardfile not located in the current directory:

$ guard --guardfile ~/.your_global_guardfile
$ guard -G ~/.your_global_guardfile # shortcut

An exhaustive list of options is available with:

$ guard help [TASK]


From version >= 0.7.0 Posix Signal handlers are no more used to interact with Guard. If you're using a version < 0.7, please refer to the README in the v0.6 branch.

When Guard do nothing you can interact with by entering a command + hitting enter:

  • stop|quit|exit|s|q|e + enter - Calls each guard's #stop method, in the same order they are declared in the Guardfile, and then quits Guard itself.
  • reload|r|z + enter - Calls each guard's #reload method, in the same order they are declared in the Guardfile.
  • pause|p + enter - Toggle files modification listening. Useful when switching git branches.
  • just enter (no commands) - Calls each guard's #run_all method, in the same order they are declared in the Guardfile.

Available Guards

A list of the available guards is present in the wiki.

Add a guard to your Guardfile

Add it to your Gemfile (inside the development group):

gem '<guard-name>'

You can list all guards installed on your system with:

$ guard list

Insert default guard's definition to your Guardfile by running this command:

$ guard init <guard-name>

You are good to go, or you can modify your guards' definition to suit your needs.

Guardfile DSL

The Guardfile DSL consists of the following methods:

  • #guard: allows you to add a guard with an optional hash of options.
  • #watch: allows you to define which files are supervised by this guard. An optional block can be added to overwrite the paths sent to the guard's #run_on_change method or to launch any arbitrary command.
  • #group: allows you to group several guards together. Groups to be run can be specified with the Guard DSL option --group (or -g). This comes in handy especially when you have a huge Guardfile and want to focus your development on a certain part. Guards that don't belong to a group are considered global and are always run.
  • #callback: allows you to execute arbitrary code before or after any of the start, stop, reload, run_all and run_on_change guards' method. You can even insert more hooks inside these methods. Please checkout the Wiki page for more details.
  • #ignore_paths: allows you to ignore top level directories altogether. This comes is handy when you have large amounts of non-source data in you project. By default .bundle, .git, log, tmp, and vendor are ignored. Currently it is only possible to ignore the immediate descendants of the watched directory.


ignore_paths 'foo', 'bar'

group 'backend' do
  guard 'bundler' do

  guard 'rspec', :cli => '--color --format doc' do
    # Regexp watch patterns are matched with Regexp#match
    watch(%r{^lib/(.+)\.rb$})         { |m| "spec/lib/#{m[1]}_spec.rb" }
    watch(%r{^spec/models/.+\.rb$})   { ["spec/models", "spec/acceptance"] }
    watch(%r{^spec/.+\.rb$})          { `say hello` }

    # String watch patterns are matched with simple '=='
    watch('spec/spec_helper.rb') { "spec" }

group 'frontend' do
  guard 'coffeescript', :output => 'public/javascripts/compiled' do

  guard 'livereload' do

Using a Guardfile without the guard binary

The Guardfile DSL can also be used in a programmatic fashion by calling directly Guard::Dsl.evaluate_guardfile. Available options are as follow:

  • :guardfile - The path to a valid Guardfile.
  • :guardfile_contents - A string representing the content of a valid Guardfile

Remember, without any options given, Guard will look for a Guardfile in your current directory and if it does not find one, it will look for it in your $HOME directory.

For instance, you could use it as follow:

gem 'guard'
require 'guard'


Guard::Dsl.evaluate_guardfile(:guardfile => '/your/custom/path/to/a/valid/Guardfile')
# or
Guard::Dsl.evaluate_guardfile(:guardfile_contents => "
  guard 'rspec' do

Listing defined guards/groups for the current project

You can list the defined groups and guards for the current Guardfile from the command line using guard show or guard -T:

# guard -T

Group backend:
  rspec: cli => "--color --format doc"
Group frontend:
  coffeescript: output => "public/javascripts/compiled"

User config file

If a .guard.rb is found in your home directory, it will be appended to the Guardfile. This can be used for tasks you want guard to handle but other users probably don't. For example, indexing your source tree with Ctags:

guard 'shell' do
  watch(%r{^(?:app|lib)/.+\.rb$}) { `ctags -R` }

Create a new guard

Creating a new guard is very easy, just create a new gem (bundle gem if you use Bundler) with this basic structure:

.travis.yml  # bonus point! # bonus point!
        Guardfile # needed for `guard init <guard-name>`
test/ # or spec/

Guard::GuardName (in lib/guard/guard-name.rb) must inherit from Guard::Guard and should overwrite at least one of the five basic Guard::Guard instance methods.

Here is an example scaffold for lib/guard/guard-name.rb:

require 'guard'
require 'guard/guard'

module Guard
  class GuardName < Guard

    def initialize(watchers=[], options={})
      # init stuff here, thx!

    # =================
    # = Guard methods =
    # =================

    # If one of those methods raise an exception, the Guard::GuardName instance
    # will be removed from the active guards.

    # Called once when Guard starts
    # Please override initialize method to init stuff
    def start

    # Called on Ctrl-C signal (when Guard quits)
    def stop

    # Called on Ctrl-Z signal
    # This method should be mainly used for "reload" (really!) actions like reloading passenger/spork/bundler/...
    def reload

    # Called on Ctrl-\ signal
    # This method should be principally used for long action like running all specs/tests/...
    def run_all

    # Called on file(s) modifications
    def run_on_change(paths)


Please take a look at the existing guards' source code for more concrete example and inspiration.

Alternatively, a new guard can be added inline to a Guardfile with this basic structure:

require 'guard/guard'

module ::Guard
  class InlineGuard < ::Guard::Guard
    def run_all

    def run_on_change(paths)

Here is a very cool example by @avdi :


Pull requests are very welcome! Please try to follow these simple "rules", though:

  • Please create a topic branch for every separate change you make;
  • Make sure your patches are well tested;
  • Update the README (if applicable);
  • Update the CHANGELOG (maybe not for a typo but don't hesitate!);
  • Please do not change the version number.

For questions please join us on our Google group or on #guard (


Thibaud Guillaume-Gentil