Class: Spawner::Main

Inherits:
Object
  • Object
show all
Defined in:
lib/spawner/main.rb

Overview

The main application for the “spawner” command line tool.

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Main

Initializes a new main object.



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# File 'lib/spawner/main.rb', line 21

def initialize
  @config = {}
end

Instance Attribute Details

#config ⇒ Object (readonly)

The configuration options parsed from the command line arguments



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# File 'lib/spawner/main.rb', line 17

def config
  @config
end

Class Method Details

.run(args) ⇒ Object

Convenience method for creating and running.



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# File 'lib/spawner/main.rb', line 12

def self.run( args )
  new.run( args )
end

Instance Method Details

#parse(args) ⇒ Object

Parse the given array of command line args and return the command to run.



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# File 'lib/spawner/main.rb', line 50

def parse( args )
  opts = OptionParser.new
  opts.banner = 'Usage: spawner [options] command'

  opts.separator ''
  opts.on('-s', '--spawn NUMBER', Integer,
          'number of child processes to spawn') {|s| config[:spawn] = s}
  opts.on('-p', '--pause SECONDS', Float,
          'time to wait before re-spawning') {|p| config[:pause] = p}

  opts.separator ''
  opts.on('--stdin FILENAME', String,
          'child process reads input from here') {|fn| config[:stdin] = fn}
  opts.on('--stdout FILENAME', String,
          'child process writes output to here') {|fn| config[:stdout] = fn}
  opts.on('--stderr FILENAME', String,
          'child process writes errors to here') {|fn| config[:stderr] = fn}

  opts.separator ''
  opts.separator 'common options:'

  opts.on_tail( '-h', '--help', 'show this message' ) do
    puts opts
    exit
  end
  opts.on_tail( '--version', 'show version' ) do
    puts "spawner #{::Spawner::VERSION}"
    exit
  end

  opts.parse! args
  if args.empty?
    puts opts
    abort "missing command"
  end
end

#run(args) ⇒ Object

Parse the given command line args and run the command according to the arguments passed in.



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# File 'lib/spawner/main.rb', line 28

def run( args )
  parse(args)
  args << config

  spawner = ::Spawner.new(*args)
  Signal.trap('INT') { spawner.stop }

  count = config[:spawn] || 1
  puts "starting #{count} child processes (Ctrl-C to quit)"

  spawner.start
  spawner.join

  puts 'sleeping for 7 seconds'
  sleep 7

  puts 'finished'
end