Module: Trollop

Defined in:
lib/convoy/trollop.rb

Defined Under Namespace

Classes: CommandlineError, HelpNeeded, Parser, VersionNeeded

Constant Summary collapse

VERSION = 
"2.0"
FLOAT_RE =

Regex for floating point numbers

/^-?((\d+(\.\d+)?)|(\.\d+))([eE][-+]?[\d]+)?$/
PARAM_RE =

Regex for parameters

/^-(-|\.$|[^\d\.])/

Class Method Summary collapse

Class Method Details

.die(arg, msg = nil) ⇒ Object

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?



851
852
853
854
855
856
857
 
# File 'lib/convoy/trollop.rb', line 851

def die arg, msg=nil
    if @last_parser
        @last_parser.die arg, msg
    else
        raise ArgumentError, "Trollop::die can only be called after Trollop::options"
    end
end

.options(args = ARGV, *a, &b) ⇒ Object

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 :name, "Monkey name", :type => :string        # a string --name <s>, defaulting to nil
  opt :num_limbs, "Number of limbs", :default => 4  # an integer --num-limbs <i>, defaulting to 4
end

## if called with no arguments
p opts # => {:monkey=>false, :name=>nil, :num_limbs=>4, :help=>false}

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

See more examples at trollop.rubyforge.org.



786
787
788
789
 
# File 'lib/convoy/trollop.rb', line 786

def options args=ARGV, *a, &b
    @last_parser = Parser.new(*a, &b)
    with_standard_exception_handling(@last_parser) { @last_parser.parse args }
end

.with_standard_exception_handling(parser) ⇒ Object

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.



816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
 
# File 'lib/convoy/trollop.rb', line 816

def with_standard_exception_handling(parser)
    begin
        yield
    rescue CommandlineError => e
        raise Convoy::UserError.new(e.message, e)
            #$stderr.puts "Error: #{e.message}."
            #$stderr.puts "Try --help for help."
            #exit(1)
    rescue HelpNeeded
        parser.current_help_formatter ? parser.current_help_formatter.print(parser) : parser.educate
        exit
    rescue VersionNeeded
        puts parser.version
        exit
    end
end