Method: GetoptLong#get

Defined in:

lib/getoptlong.rb

#get ⇒ Object Also known as: get_option

Get next option name and its argument, as an Array of two elements.

The option name is always converted to the first (preferred) name given in the original options to GetoptLong.new.

Example: [‘–option’, ‘value’]

Returns nil if the processing is complete (as determined by STATUS_TERMINATED).

# File 'lib/getoptlong.rb', line 427

def get
  option_name, option_argument = nil, ''

  #
  # Check status.
  #
  return nil if @error != nil
  case @status
  when STATUS_YET
    @status = STATUS_STARTED
  when STATUS_TERMINATED
    return nil
  end

  #
  # Get next option argument.
  #
  if 0 < @rest_singles.length
    argument = '-' + @rest_singles
  elsif (ARGV.length == 0)
    terminate
    return nil
  elsif @ordering == PERMUTE
    while 0 < ARGV.length && ARGV[0] !~ /\A-./
      @non_option_arguments.push(ARGV.shift)
    end
    if ARGV.length == 0
      terminate
      return nil
    end
    argument = ARGV.shift
  elsif @ordering == REQUIRE_ORDER
    if (ARGV[0] !~ /\A-./)
      terminate
      return nil
    end
    argument = ARGV.shift
  else
    argument = ARGV.shift
  end

  #
  # Check the special argument `--'.
  # `--' indicates the end of the option list.
  #
  if argument == '--' && @rest_singles.length == 0
    terminate
    return nil
  end

  #
  # Check for long and short options.
  #
  if argument =~ /\A(--[^=]+)/ && @rest_singles.length == 0
    #
    # This is a long style option, which start with `--'.
    #
    pattern = $1
    if @canonical_names.include?(pattern)
      option_name = pattern
    else
      #
      # The option `option_name' is not registered in `@canonical_names'.
      # It may be an abbreviated.
      #
      matches = []
      @canonical_names.each_key do |key|
        if key.index(pattern) == 0
          option_name = key
          matches << key
        end
      end
      if 2 <= matches.length
        set_error(AmbiguousOption, "option `#{argument}' is ambiguous between #{matches.join(', ')}")
      elsif matches.length == 0
        set_error(InvalidOption, "unrecognized option `#{argument}'")
      end
    end

    #
    # Check an argument to the option.
    #
    if @argument_flags[option_name] == REQUIRED_ARGUMENT
      if argument =~ /=(.*)/m
        option_argument = $1
      elsif 0 < ARGV.length
        option_argument = ARGV.shift
      else
        set_error(MissingArgument,
                  "option `#{argument}' requires an argument")
      end
    elsif @argument_flags[option_name] == OPTIONAL_ARGUMENT
      if argument =~ /=(.*)/m
        option_argument = $1
      elsif 0 < ARGV.length && ARGV[0] !~ /\A-./
        option_argument = ARGV.shift
      else
        option_argument = ''
      end
    elsif argument =~ /=(.*)/m
      set_error(NeedlessArgument,
                "option `#{option_name}' doesn't allow an argument")
    end

  elsif argument =~ /\A(-(.))(.*)/m
    #
    # This is a short style option, which start with `-' (not `--').
    # Short options may be catenated (e.g. `-l -g' is equivalent to
    # `-lg').
    #
    option_name, ch, @rest_singles = $1, $2, $3

    if @canonical_names.include?(option_name)
      #
      # The option `option_name' is found in `@canonical_names'.
      # Check its argument.
      #
      if @argument_flags[option_name] == REQUIRED_ARGUMENT
        if 0 < @rest_singles.length
          option_argument = @rest_singles
          @rest_singles = ''
        elsif 0 < ARGV.length
          option_argument = ARGV.shift
        else
          # 1003.2 specifies the format of this message.
          set_error(MissingArgument, "option requires an argument -- #{ch}")
        end
      elsif @argument_flags[option_name] == OPTIONAL_ARGUMENT
        if 0 < @rest_singles.length
          option_argument = @rest_singles
          @rest_singles = ''
        elsif 0 < ARGV.length && ARGV[0] !~ /\A-./
          option_argument = ARGV.shift
        else
          option_argument = ''
        end
      end
    else
      #
      # This is an invalid option.
      # 1003.2 specifies the format of this message.
      #
      if ENV.include?('POSIXLY_CORRECT')
        set_error(InvalidOption, "invalid option -- #{ch}")
      else
        set_error(InvalidOption, "invalid option -- #{ch}")
      end
    end
  else
    #
    # This is a non-option argument.
    # Only RETURN_IN_ORDER fell into here.
    #
    return '', argument
  end

  return @canonical_names[option_name], option_argument
end