force run feature

README.md

@@ -1,15 +1,17 @@
-Want to restart your Rails dev server whilst you work? Now you can!
+Want to restart your Rails development server whilst you work? Now you can!
 
     guard 'rails', :port => 5000 do
       watch('Gemfile.lock')
       watch(%r{^(config|lib)/.*})
     end
 
-Three fun options!
+Four fun options!
 
-* `:port` is the port number to run on (default 3000)
+* `:port` is the port number to run on (default `3000`)
-* `:environment` is the environment to use (default development)
+* `:environment` is the environment to use (default `development`)
-* `:start_on_start` will start the server when starting Guard (default true)
+* `:start_on_start` will start the server when starting Guard (default `true`)
+* `:force_run` kills any process that's holding open the listen port before attempting to (re)start Rails (default `false`).
 
-This is super-alpha, but it works for me!
+This is super-alpha, but it works for me! Only really hand-tested in Mac OS X. Feel free to fork'n'fix for other
+OSes, and to add some real tests.
 

lib/guard/rails.rb

@@ -1,5 +1,6 @@
 require 'guard'
 require 'guard/guard'
+require 'rbconfig'
 
 module Guard
   class Rails < ::Guard::Guard
@@ -7,7 +8,12 @@ module Guard
 
     def initialize(watchers = [], options = {})
       super
-      @options = { :port => 3000, :environment => 'development', :start_on_start => true }.merge(options)
+      @options = {
+        :port => 3000,
+        :environment => 'development',
+        :start_on_start => true,
+        :force_run => false
+      }.merge(options)
     end
 
     def start
@@ -36,6 +42,7 @@ module Guard
     end
 
     def start_rails
+      kill_unmanaged_pid! if options[:force_run]
       system %{sh -c 'cd #{Dir.pwd} && rails s -e #{options[:environment]} -p #{options[:port]} --pid #{pid_file} &'}
       while !File.file?(pid_file)
         sleep 0.5
@@ -48,6 +55,23 @@ module Guard
         system %{kill -INT #{File.read(pid_file).strip}}
       end
     end
+
+    def unmanaged_pid
+      if RbConfig::CONFIG['host_os'] =~ /darwin/
+        %x{lsof -P}.each_line { |line|
+          if line["*:#{options[:port]} "]
+            return line.split("\s")[1]
+          end
+        }
+      end
+      nil
+    end
+
+    def kill_unmanaged_pid!
+      if pid = unmanaged_pid
+        system %{kill -INT #{pid}}
+      end
+    end
   end
 end