Class: Gem::Commands::HelpCommand

Inherits:
Gem::Command show all
Defined in:
lib/rubygems/commands/help_command.rb

Constant Summary collapse

EXAMPLES =

:stopdoc:

<<-EOF
Some examples of 'gem' usage.

* Install 'rake', either from local directory or remote server:

  gem install rake

* Install 'rake', only from remote server:

  gem install rake --remote

* Install 'rake', but only version 0.3.1, even if dependencies
are not met, and into a user-specific directory:

  gem install rake --version 0.3.1 --force --user-install

* List local gems whose name begins with 'D':

  gem list D

* List local and remote gems whose name contains 'log':

  gem search log --both

* List only remote gems whose name contains 'log':

  gem search log --remote

* Uninstall 'rake':

  gem uninstall rake

* Create a gem:

  See http://guides.rubygems.org/make-your-own-gem/

* See information about RubyGems:

  gem environment

* Update all gems on your system:

  gem update
EOF
PLATFORMS = 
<<-'EOF'
RubyGems platforms are composed of three parts, a CPU, an OS, and a
version.  These values are taken from values in rbconfig.rb.  You can view
your current platform by running `gem environment`.

RubyGems matches platforms as follows:

* The CPU must match exactly, unless one of the platforms has
  "universal" as the CPU.
* The OS must match exactly.
* The versions must match exactly unless one of the versions is nil.

For commands that install, uninstall and list gems, you can override what
RubyGems thinks your platform is with the --platform option.  The platform
you pass must match "#{cpu}-#{os}" or "#{cpu}-#{os}-#{version}".  On mswin
platforms, the version is the compiler version, not the OS version.  (Ruby
compiled with VC6 uses "60" as the compiler version, VC8 uses "80".)

Example platforms:

x86-freebsd        # Any FreeBSD version on an x86 CPU
universal-darwin-8 # Darwin 8 only gems that run on any CPU
x86-mswin32-80     # Windows gems compiled with VC8

When building platform gems, set the platform in the gem specification to
Gem::Platform::CURRENT.  This will correctly mark the gem with your ruby's
platform.
EOF

Instance Attribute Summary

Attributes inherited from Gem::Command

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

Instance Method Summary collapse

Methods inherited from Gem::Command

add_common_option, #add_extra_args, #add_option, add_specific_extra_args, #begins?, build_args, build_args=, common_options, #defaults_str, #description, extra_args, extra_args=, #get_all_gem_names, #get_all_gem_names_and_versions, #get_one_gem_name, #get_one_optional_argument, #handle_options, #handles?, #invoke, #invoke_with_build_args, #merge_options, #remove_option, #show_help, #show_lookup_failure, specific_extra_args, specific_extra_args_hash, #when_invoked

Methods included from UserInteraction

#alert, #alert_error, #alert_warning, #ask, #ask_for_password, #ask_yes_no, #choose_from_list, #say, #terminate_interaction

Methods included from DefaultUserInteraction

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

Constructor Details

#initialize ⇒ HelpCommand

:startdoc:



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# File 'lib/rubygems/commands/help_command.rb', line 81

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

Instance Method Details

#arguments ⇒ Object

:nodoc:



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# File 'lib/rubygems/commands/help_command.rb', line 85

def arguments # :nodoc:
  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/commands/help_command.rb', line 98

def execute
  command_manager = Gem::CommandManager.instance
  arg = options[:args][0]

  if begins? "commands", arg then
    out = []
    out << "GEM commands are:"
    out << nil

    margin_width = 4

    desc_width = command_manager.command_names.map { |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 then
    say Gem::Command::HELP

  elsif begins? "examples", arg then
    say EXAMPLES

  elsif begins? "platforms", arg then
    say PLATFORMS

  elsif options[:help] then
    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 then
    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::Command::HELP
  end
end

#usage ⇒ Object

:nodoc:



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# File 'lib/rubygems/commands/help_command.rb', line 94

def usage # :nodoc:
  "#{program_name} ARGUMENT"
end