Guard

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 (irc.freenode.net).

Features

• FSEvent support on Mac OS X 10.5+ (without RubyCocoa!, rb-fsevent gem, >= 0.3.5 required).
• Inotify support on Linux (rb-inotify gem, >= 0.5.1 required).
• Directory Change Notification support on Windows (rb-fchange, >= 0.0.2 required).
• Polling on the other operating systems (help us to support more OS).
• Automatic & Super fast (when polling is not used) files modifications detection (even new files are detected).
• Growl notifications (growl_notify gem or growlnotify & growl gem required).
• Libnotify notifications (libnotify gem required).
• Tested against Ruby 1.8.7, 1.9.2 and REE.

Screencast

Ryan Bates made a screencast on Guard, you can view it here: http://railscasts.com/episodes/264-guard

Install

Install the gem:

$ gem install guard

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

gem 'guard'

Generate an empty Guardfile with:

$ guard init

You may optionally place a .Guardfile in your home directory to use it across multiple projects.

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

Install either the growl_notify or the growl gem if you want notification support:

$ gem install growl_notify
$ # or
$ gem install growl

And add them to your Gemfile:

gem 'rb-fsevent'
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 this is currently known to not work in conjunction with Spork.

On Linux

Install the rb-inotify gem for inotify support:

$ gem install rb-inotify

Install the Libnotify gem if you want 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 Notifu gem if you want notification support:

$ gem install rb-notifu

And add them to your Gemfile:

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

Usage

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]

Signal handlers

Signal handlers are used to interact with Guard:

• Ctrl-C - Calls each guard's #stop method, in the same order they are declared in the Guardfile, and then quits Guard itself.
• Ctrl-\ - Calls each guard's #run_all method, in the same order they are declared in the Guardfile.
• Ctrl-Z - Calls each guard's #reload method, in the same order they are declared in the Guardfile.

You can read more about configure the signal keyboard shortcuts in the wiki.

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 just three simple methods: #guard, #watch & #group.

Required:

• The #guard method allows you to add a guard with an optional hash of options.

Optional:

• The #watch method 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.
• The #group method 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.
• The #ignore_paths method 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.

Example:

ignore_paths 'foo', 'bar'

group 'backend' do
  guard 'bundler' do
    watch('Gemfile')
  end

  guard 'rspec', :cli => '--color --format doc' do
    # Regexp watch patterns are matched with Regexp#match
    watch(%r{^spec/.+_spec\.rb$})
    watch(%r{^lib/(.+)\.rb$})         { |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" }
  end
end

group 'frontend' do
  guard 'coffeescript', :output => 'public/javascripts/compiled' do
    watch(%r{^app/coffeescripts/.+\.coffee$})
  end

  guard 'livereload' do
    watch(%r{^app/.+\.(erb|haml)$})
  end
end

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.setup

Guard::Dsl.evaluate_guardfile(:guardfile => '/your/custom/path/to/a/valid/Guardfile')
# or
Guard::Dsl.evaluate_guardfile(:guardfile_contents => "
  guard 'rspec' do
    watch(%r{^spec/.+_spec\.rb$})
  end
")

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

(global):
  shell
Group backend:
  bundler
  rspec: cli => "--color --format doc"
Group frontend:
  coffeescript: output => "public/javascripts/compiled"
  livereload

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` }
end

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!
CHANGELOG.md # bonus point!
Gemfile
guard-name.gemspec
Guardfile
lib/
  guard/
    guard-name/
      templates/
        Guardfile # needed for `guard init <guard-name>`
      version.rb
    guard-name.rb
test/ # or spec/
README.md

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={})
      super
      # init stuff here, thx!
    end

    # =================
    # = 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
      true
    end

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

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

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

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

  end
end

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
      true
    end

    def run_on_change(paths)
      true
    end
  end
end

Here is a very cool example by @avdi : http://avdi.org/devblog/2011/06/15/a-guardfile-for-redis

Development

• Source hosted at GitHub.
• Report issues and feature requests to GitHub Issues.

Pull requests are very welcome! Make sure your patches are well tested. Please create a topic branch for every separate change you make. Please do not change the version in your pull-request.

For questions please join us on our Google group or on #guard (irc.freenode.net).

Author

Thibaud Guillaume-Gentil

Contributors

https://github.com/guard/guard/contributors