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

* Update your local version of RubyGems

  gem update --system
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 or the local CPU starts with "arm" and the gem's
  CPU is exactly "arm" (for gems that support generic ARM architecture).
* 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".)

For the ARM architecture, gems with a platform of "arm-linux" should run on a
reasonable set of ARM CPUs and not depend on instructions present on a limited
subset of the architecture.  For example, the binary should run on platforms
armv5, armv6hf, armv6l, armv7, etc.  If you use the "arm-linux" platform
please test your gem on a variety of ARM hardware before release to ensure it
functions correctly.

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
armv7-linux        # Gem complied for an ARMv7 CPU running linux
arm-linux          # Gem compiled for any ARM CPU running linux

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_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 95

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

  @command_manager = Gem::CommandManager.instance
end

Instance Method Details

#arguments ⇒ Object

:nodoc:



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# File 'lib/rubygems/commands/help_command.rb', line 101

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 114

def execute
  arg = options[:args][0]

  if begins? "commands", arg then
    show_commands

  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
    show_help

  elsif arg then
    show_command_help arg

  else
    say Gem::Command::HELP
  end
end

#show_command_help(command_name) ⇒ Object

:nodoc:



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# File 'lib/rubygems/commands/help_command.rb', line 179

def show_command_help command_name # :nodoc:
  command_name = command_name.downcase

  possibilities = @command_manager.find_command_possibilities command_name

  if possibilities.size == 1 then
    command = @command_manager[possibilities.first]
    command.invoke("--help")
  elsif possibilities.size > 1 then
    alert_warning "Ambiguous command #{command_name} (#{possibilities.join(', ')})"
  else
    alert_warning "Unknown command #{command_name}.  Try: gem help commands"
  end
end

#show_commands ⇒ Object

:nodoc:



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# File 'lib/rubygems/commands/help_command.rb', line 140

def show_commands # :nodoc:
  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|
    command = @command_manager[cmd_name]

    summary =
      if command then
        command.summary
      else
        "[No command found for #{cmd_name}]"
      end

    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")
end

#show_help ⇒ Object

:nodoc:



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# File 'lib/rubygems/commands/help_command.rb', line 194

def show_help # :nodoc:
  command = @command_manager[options[:help]]
  if command then
    # help with provided command
    command.invoke("--help")
  else
    alert_error "Unknown command #{options[:help]}.  Try 'gem help commands'"
  end
end

#usage ⇒ Object

:nodoc:



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# File 'lib/rubygems/commands/help_command.rb', line 110

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