Class: RR::CommandRunner

Inherits:
Object
  • Object
show all
Defined in:
lib/rubyrep/command_runner.rb

Overview

This class implements the functionality to dispatch rubyrep commands.

Class Method Summary collapse

Class Method Details

.commands ⇒ Object

Returns a hash of all commands registered with #register.



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# File 'lib/rubyrep/command_runner.rb', line 11

def self.commands
  @commands ||= {}
end

.register(commands) ⇒ Object

Registers one or multiple commands. commands is a hash with

  • key: name of the command

  • value: a command hash defining the command

A command hash consists of

  • :description: short description of the command

  • :command: an object / class implementing the hash.

    Must have a method

# runs a command
# * +args+: array of command line parameters
#           note: will not contain the command name itself.
def run(args)



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# File 'lib/rubyrep/command_runner.rb', line 29

def self.register(commands)
  self.commands.merge!(commands)
end

.run(args) ⇒ Object

Dispatches commands as per given command line parameters.

  • args: array of command line parameters



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# File 'lib/rubyrep/command_runner.rb', line 41

def self.run(args)
  status = 0
  options = {}

  parser = OptionParser.new do |opts|
    opts.banner = <<EOS
Usage: #{$0} [general options] command [parameters, ...]

Asynchronous master-master replication of relational databases.
EOS
    opts.separator ""
    opts.separator "Available options:"

    opts.on("--verbose", "Show errors with full stack trace") do
      options[:verbose] = true
    end

    opts.on("-v", "--version", "Show version information.") do
      show_version
      options = nil
    end

    opts.on_tail("--help", "Show this message") do
      $stderr.puts opts
      
      $stderr.puts "\nAvailable commands:"
      commands.sort.each do |command_name, command_hash|
        $stderr.puts "  #{command_name.ljust(15)} #{command_hash[:description]}"
      end

      options = nil
    end
  end

  begin

    # extract general options
    general_args = []
    until args.empty?
      if args[0] =~ /^-/
        general_args << args.shift
      else
        break
      end
    end

    # parse general options
    parser.parse!(general_args)

    # process commands
    if options # this will be +nil+ if the --help or --version are specified
      if args.empty?
        $stderr.puts "No command specified.\n\n"
        run(['--help'])
        status = 1
      else
        command = args[0]
        if command == 'help' and args.size == 1
          run(['--help'])
          status = 0
        elsif commands.include? command
          status = commands[command][:command].run(args.slice(1, 1_000_000))
        else
          $stderr.puts "Error: Unknown command specified.\n\n"
          run(['--help'])
          status = 1
        end
      end
    end
  rescue Exception => e
    $stderr.puts "Exception caught: #{e}"
    $stderr.puts e.backtrace if options && options[:verbose]
    status = 1
  end

  return status
end

.show_version ⇒ Object

Prints the version to stderr



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# File 'lib/rubyrep/command_runner.rb', line 34

def self.show_version
  $stdout.puts "rubyrep version #{RR::VERSION}"
end