module Puppet::Util::CommandLine::Trollop

Constants

FLOAT_RE: Regex for floating point numbers
PARAM_RE: Regex for parameters
VERSION

Public Class Methods

die(arg, msg=nil) click to toggle source

Informs the user that their usage of 'arg' was wrong, as detailed by 'msg', and dies. Example:

options do
  opt :volume, :default => 0.0
end

die :volume, "too loud" if opts[:volume] > 10.0
die :volume, "too soft" if opts[:volume] < 0.1

In the one-argument case, simply print that message, a notice about -h, and die. Example:

options do
  opt :whatever # ...
end

Trollop::die "need at least one filename" if ARGV.empty?

    # File lib/puppet/util/command_line/trollop.rb
812 def die arg, msg=nil
813   if @last_parser
814     @last_parser.die arg, msg
815   else
816     #TRANSLATORS 'Trollop' is the name of a module and 'die' and 'options' are methods in it and should not be translated.
817     raise ArgumentError, _("Trollop::die can only be called after Trollop::options")
818   end
819 end

options(args=ARGV, *a, &b) click to toggle source

The easy, syntactic-sugary entry method into Trollop. Creates a Parser, passes the block to it, then parses args with it, handling any errors or requests for help or version information appropriately (and then exiting). Modifies args in place. Returns a hash of option values.

The block passed in should contain zero or more calls to opt (Parser#opt), zero or more calls to text (Parser#text), and probably a call to version (Parser#version).

The returned block contains a value for every option specified with opt. The value will be the value given on the commandline, or the default value if the option was not specified on the commandline. For every option specified on the commandline, a key “<option name>_given” will also be set in the hash.

Example:

require 'trollop'
opts = Trollop::options do
  opt :monkey, "Use monkey mode"                     # a flag --monkey, defaulting to false
  opt :goat, "Use goat mode", :default => true       # a flag --goat, defaulting to true
  opt :num_limbs, "Number of limbs", :default => 4   # an integer --num-limbs <i>, defaulting to 4
  opt :num_thumbs, "Number of thumbs", :type => :int # an integer --num-thumbs <i>, defaulting to nil
end

## if called with no arguments
p opts # => { :monkey => false, :goat => true, :num_limbs => 4, :num_thumbs => nil }

## if called with --monkey
p opts # => {:monkey_given=>true, :monkey=>true, :goat=>true, :num_limbs=>4, :help=>false, :num_thumbs=>nil}

See more examples at trollop.rubyforge.org.

    # File lib/puppet/util/command_line/trollop.rb
748 def options args=ARGV, *a, &b
749   @last_parser = Parser.new(*a, &b)
750   with_standard_exception_handling(@last_parser) { @last_parser.parse args }
751 end

with_standard_exception_handling(parser) { || ... } click to toggle source

If Trollop::options doesn't do quite what you want, you can create a Parser object and call Parser#parse on it. That method will throw CommandlineError, HelpNeeded and VersionNeeded exceptions when necessary; if you want to have these handled for you in the standard manner (e.g. show the help and then exit upon an HelpNeeded exception), call your code from within a block passed to this method.

Note that this method will call System#exit after handling an exception!

Usage example:

require 'trollop'
p = Trollop::Parser.new do
  opt :monkey, "Use monkey mode"                     # a flag --monkey, defaulting to false
  opt :goat, "Use goat mode", :default => true       # a flag --goat, defaulting to true
end

opts = Trollop::with_standard_exception_handling p do
  o = p.parse ARGV
  raise Trollop::HelpNeeded if ARGV.empty? # show help screen
  o
end

Requires passing in the parser object.

    # File lib/puppet/util/command_line/trollop.rb
778 def with_standard_exception_handling parser
779   begin
780     yield
781   rescue CommandlineError => e
782     $stderr.puts _("Error: %{value0}.") % { value0: e.message }
783     $stderr.puts _("Try --help for help.")
784     exit(-1)
785   rescue HelpNeeded
786     parser.educate
787     exit
788   rescue VersionNeeded
789     puts parser.version
790     exit
791   end
792 end

Private Instance Methods