bash script to start and stop resque workers.

resque.rb

#!/usr/bin/env ruby

require File.expand_path(File.join(File.dirname(__FILE__), '..', 'config', 'environment'))
require 'optparse'
require 'timeout'
require 'ostruct'

USAGE       = "usage: script/resque command [options]"
COMMANDS    = %w( start status stop )
TIMEOUT     = 60

DEFAULTS    = { :count      => 1,
                :queue      => '*',
                :interval   => 5.0,
                :background => 'yes',
                :verbose    => 1 }.freeze

PARAMETERS  = { 'count [N]'         => 'Number of resque forks',
                'queues [a,b,c]'    => 'Queues to observe',
                'interval [Float]'  => 'Polling frequency' }.freeze

################################################################
# PARAMETER PARSING
################################################################

def options
  @options ||= parse_options(:pidfile => pidfile)
end

def parse_options(additional = {})
  OpenStruct.new(DEFAULTS.dup.update(additional)).tap do |options|

    OptionParser.new do |opts|
      opts.banner = USAGE

      # optional parameters
      PARAMETERS.each do |option, description|
        flag = option.first
        name = option.split(' ').first

        opts.on("-#{flag}", "--#{option}", description) do |value|
          options.send("#{name}=", value) if value
        end
      end

      opts.on("-h", "--help", "Show this message") { puts opts;  exit }
    end.parse!(ARGV)

    options.command = ARGV.first

    unless COMMANDS.include?(options.command)
      puts USAGE
      exit(-1)
    end
  end
end

def pidfile
  i = 0
  loop do
    file = Rails.root.join('tmp', 'pids', "resque_worker.#{i += 1}.pid")
    return file   unless File.exists?(file)
  end
end

################################################################
# HELPER METHODS
################################################################

def parameterized_options
  options.marshal_dump.map { |p, v| "#{p.to_s.upcase}=#{v}" }.join(' ')
end

def pids
  files = Dir[Rails.root.join('tmp', 'pids', 'resque_worker.*.pid')]
  pids  = files.map do |file|
    [File.open(file) { |f| f.read.strip.to_i }, file] rescue nil
  end

  Hash[*pids.compact.flatten]
end

def kill!(signal)
  pids.each do |pid, file|
    begin
      Process.kill(signal, pid)
    rescue Errno::ESRCH
      File.delete(file)
    end
  end
end

################################################################
# COMMANDS
################################################################

def start
  `#{parameterized_options} rake resque:work`
end

def status
  pids.each do |pid, file|
    puts `ps -p #{pid} | sed -n 2p`
  end
end

def stop
  kill!('QUIT')

  begin
    Timeout::timeout(TIMEOUT) do
      sleep(1) while pids.present?
    end
  rescue Timeout::Error
    kill!('TERM')
    FileUtils.rm_f(pids.values)
  end
end

################################################################
# RUN COMMAND
################################################################

send(options.command)

This is a Ruby script, not a bash script! But yes, it can be run from the shell.