BasicDaemon¶ ↑

A basic library for creating daemonized processes

This library works with Ruby 1.8, Ruby 1.9, and JRuby and is licensed under the MIT License.

Installation¶ ↑

The basic_daemon gem is hosted on GemCutter (gemcutter.org). This requires that you have gemcutter.org in your gem sources.

Install the basic_daemon gem:

sudo gem install basic_daemon

Gettings Started¶ ↑

There are currently two ways of using the basic_daemon library: 1) Objected Oriented; 2) Functional.

Object Oriented ¶ ↑

The basic idea here is to subclass BasicDaemon and overwride the “run” method.

require 'basic_daemon'

class MyDaemon < BasicDaemon
  def run
    foo = open("/tmp/out", "w")

    i = 1

    while true do
      foo.puts "loop: #{i}"
      foo.flush
      sleep 2

      i += 1
    end
  end
end

daemon = MyDaemon.new

if ARGV[0] == 'start'
  daemon.start
elsif ARGV[0] == 'stop'
  daemon.stop
  exit!
elsif ARGV[0] == 'restart'
  daemon.restart
else
  STDERR.puts "Usage: foo_daemon.rb <start|stop|restart>"
  exit!
end

Functional¶ ↑

Rather than subclassing BasicDaemon, a block is just passed to the start method.

require 'basic_daemon'

daemon = BasicDaemon.new

process = Proc.new do
    foo = open("/tmp/out", "w")

    i = 1

    while true do
      foo.puts "loop: #{i}"
      foo.flush
      sleep 2

      i += 1
    end
  end

if ARGV[0] == 'start'
  daemon.start &process
elsif ARGV[0] == 'stop'
  daemon.stop
  exit!
elsif ARGV[0] == 'restart'
  daemon.restart &process
else
  STDERR.puts "Usage: foo_daemon.rb <start|stop|restart>"
  exit!
end

Arguments¶ ↑

BasicDaemon creates file to store the process ID (PID). By default, this file is given the same name as the calling script sans the file extension and is stored in the /tmp directory. Also by default, the directory the calling script is working in is changed to the root directory (‘/’).

Each argument, :pidfile, :piddir, :workingdir, can be changed upon instantiation of the class.

Example:¶ ↑

Most Linux users will want to instantiate thusly:

BasicDaemon.new(:piddir => '/var/lock')

samullen/basic_daemon