Class: Gem::HelpCommand

Inherits:
Command show all
Includes:
CommandAids
Defined in:
lib/rubygems/gem_commands.rb

Instance Attribute Summary

Attributes inherited from Command

#command, #defaults, #options, #program_name, #summary

Instance Method Summary collapse

Methods included from CommandAids

#begins?, #get_all_gem_names, #get_one_gem_name, #get_one_optional_argument

Methods inherited from Command

add_common_option, #add_option, add_specific_extra_args, common_options, #defaults_str, extra_args, extra_args=, #handles?, #invoke, #merge_options, #remove_option, #show_help, specific_extra_args, specific_extra_args_hash, #when_invoked

Methods included from DefaultUserInteraction

#ui, ui, #ui=, ui=, #use_ui, use_ui

Constructor Details

#initialize ⇒ HelpCommand

Returns a new instance of HelpCommand.



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# File 'lib/rubygems/gem_commands.rb', line 1457

def initialize
  super('help', "Provide help on the 'gem' command")
end

Instance Method Details

#arguments ⇒ Object 



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# File 'lib/rubygems/gem_commands.rb', line 1465

def arguments
  args = <<-EOF
    commands      List all 'gem' commands
    examples      Show examples of 'gem' usage
    <command>     Show specific help for <command>
  EOF
  return args.gsub(/^\s+/, '')
end

#execute ⇒ Object 



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# File 'lib/rubygems/gem_commands.rb', line 1474

def execute
  arg = options[:args][0]
  if begins?("commands", arg)
    out = []
    out << "GEM commands are:"
    out << nil

    margin_width = 4
    desc_width = command_manager.command_names.collect {|n| n.size}.max + 4
    summary_width = 80 - margin_width - desc_width
    wrap_indent = ' ' * (margin_width + desc_width)
    format = "#{' ' * margin_width}%-#{desc_width}s%s"

    command_manager.command_names.each do |cmd_name|
      summary = command_manager[cmd_name].summary
      summary = wrap(summary, summary_width).split "\n"
      out << sprintf(format, cmd_name, summary.shift)
      until summary.empty? do
        out << "#{wrap_indent}#{summary.shift}"
      end
    end

    out << nil
    out << "For help on a particular command, use 'gem help COMMAND'."
    out << nil
    out << "Commands may be abbreviated, so long as they are unambiguous."
    out << "e.g. 'gem i rake' is short for 'gem install rake'."

    say out.join("\n")

  elsif begins?("options", arg)
    say Gem::HELP
  elsif begins?("examples", arg)
    say Gem::EXAMPLES
  elsif options[:help]
    command = command_manager[options[:help]]
    if command
      # help with provided command
      command.invoke("--help")
    else
      alert_error "Unknown command #{options[:help]}.  Try 'gem help commands'"
    end
  elsif arg
    possibilities = command_manager.find_command_possibilities(arg.downcase)
    if possibilities.size == 1
      command = command_manager[possibilities.first]
      command.invoke("--help")
    elsif possibilities.size > 1
      alert_warning "Ambiguous command #{arg} (#{possibilities.join(', ')})"
    else
      alert_warning "Unknown command #{arg}. Try gem help commands"
    end
  else
    say Gem::HELP
  end
end

#usage ⇒ Object 



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# File 'lib/rubygems/gem_commands.rb', line 1461

def usage
  "#{program_name} ARGUMENT"
end