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Class: Gem::CommandManager

Relationships & Source Files
Super Chains via Extension / Inclusion / Inheritance
Instance Chain:
Inherits: Object
Defined in: lib/rubygems/command_manager.rb

Overview

The command manager registers and installs all the individual sub-commands supported by the gem command.

Extra commands can be provided by writing a rubygems_plugin.rb file in an installed gem. You should register your command against the CommandManager instance, like this:

# file rubygems_plugin.rb
require 'rubygems/command_manager'

Gem::CommandManager.instance.register_command :edit

You should put the implementation of your command in rubygems/commands.

# file rubygems/commands/edit_command.rb
class Gem::Commands::EditCommand < Gem::Command
  # ...
end

See Command for instructions on writing gem commands.

Constant Summary

Class Method Summary

  • .instance

    Return the authoritative instance of the command manager.

  • .new ⇒ CommandManager constructor

    Register all the subcommands supported by the gem command.

  • .reset

    Reset the authoritative instance of the command manager.

Instance Attribute Summary

Instance Method Summary

UserInteraction - Included

#alert

Displays an alert statement.

#alert_error

Displays an error statement to the error output location.

#alert_warning

Displays a warning statement to the warning output location.

#ask

Asks a question and returns the answer.

#ask_for_password

Asks for a password with a prompt

#ask_yes_no

Asks a yes or no question.

#choose_from_list

Asks the user to answer question with an answer from the given list.

#say

Displays the given statement on the standard output (or equivalent).

#terminate_interaction

Terminates the RubyGems process with the given exit_code

#verbose

Calls say with msg or the results of the block if really_verbose is true.

DefaultUserInteraction - Included

Text - Included

#clean_text

Remove any non-printable characters and make the text suitable for printing.

#format_text

Wraps text to wrap characters and optionally indents by indent characters.

#levenshtein_distance

This code is based directly on the Text gem implementation Returns a value representing the “cost” of transforming str1 into str2.

#truncate_text, #min3

Constructor Details

.newCommandManager

Register all the subcommands supported by the gem command.

[ GitHub ]

  
# File 'lib/rubygems/command_manager.rb', line 105

def initialize
  require 'timeout'
  @commands = {}

  BUILTIN_COMMANDS.each do |name|
    register_command name
  end
end

Class Method Details

.instance

Return the authoritative instance of the command manager.

[ GitHub ]

  
# File 'lib/rubygems/command_manager.rb', line 83

def self.instance
  @command_manager ||= new
end

.reset

Reset the authoritative instance of the command manager.

[ GitHub ]

  
# File 'lib/rubygems/command_manager.rb', line 98

def self.reset
  @command_manager = nil
end

Instance Method Details

#[](command_name)

Returns a Command instance for command_name

[ GitHub ]

  
# File 'lib/rubygems/command_manager.rb', line 131

def [](command_name)
  command_name = command_name.intern
  return nil if @commands[command_name].nil?
  @commands[command_name] ||= load_and_instantiate(command_name)
end

#command_names

Return a sorted list of all command names as strings.

[ GitHub ]

  
# File 'lib/rubygems/command_manager.rb', line 140

def command_names
  @commands.keys.collect {|key| key.to_s}.sort
end

#find_alias_command(cmd_name)

[ GitHub ]

  
# File 'lib/rubygems/command_manager.rb', line 197

def find_alias_command(cmd_name)
  alias_name = ALIAS_COMMANDS[cmd_name]
  alias_name ? alias_name : cmd_name
end

#find_command(cmd_name)

[ GitHub ]

  
# File 'lib/rubygems/command_manager.rb', line 182

def find_command(cmd_name)
  cmd_name = find_alias_command cmd_name

  possibilities = find_command_possibilities cmd_name

  if possibilities.size > 1
    raise Gem::CommandLineError,
          "Ambiguous command #{cmd_name} matches [#{possibilities.join(', ')}]"
  elsif possibilities.empty?
    raise Gem::CommandLineError, "Unknown command #{cmd_name}"
  end

  self[possibilities.first]
end

#find_command_possibilities(cmd_name)

[ GitHub ]

  
# File 'lib/rubygems/command_manager.rb', line 202

def find_command_possibilities(cmd_name)
  len = cmd_name.length

  found = command_names.select { |name| cmd_name == name[0, len] }

  exact = found.find { |name| name == cmd_name }

  exact ? [exact] : found
end

#instance

Returns self. Allows a CommandManager instance to stand in for the class itself.

[ GitHub ]

  
# File 'lib/rubygems/command_manager.rb', line 91

def instance
  self
end

#load_and_instantiate(command_name) (private)

[ GitHub ]

  
# File 'lib/rubygems/command_manager.rb', line 214

def load_and_instantiate(command_name)
  command_name = command_name.to_s
  const_name = command_name.capitalize.gsub(/_(.)/) { $1.upcase } << "Command"
  load_error = nil

  begin
    begin
      require "rubygems/commands/#{command_name}_command"
    rescue LoadError => e
      load_error = e
    end
    Gem::Commands.const_get(const_name).new
  rescue Exception => e
    e = load_error if load_error

    alert_error clean_text("Loading command: #{command_name} (#{e.class})\n\t#{e}")
    ui.backtrace e
  end
end

#process_args(args, build_args = nil)

[ GitHub ]

  
# File 'lib/rubygems/command_manager.rb', line 159

def process_args(args, build_args=nil)
  if args.empty?
    say Gem::Command::HELP
    terminate_interaction 1
  end

  case args.first
  when '-h', '--help' then
    say Gem::Command::HELP
    terminate_interaction 0
  when '-v', '--version' then
    say Gem::VERSION
    terminate_interaction 0
  when /^-/ then
    alert_error clean_text("Invalid option: #{args.first}. See 'gem --help'.")
    terminate_interaction 1
  else
    cmd_name = args.shift.downcase
    cmd = find_command cmd_name
    cmd.invoke_with_build_args args, build_args
  end
end

#register_command(command, obj = false)

Register the Symbol command as a gem command.

[ GitHub ]

  
# File 'lib/rubygems/command_manager.rb', line 117

def register_command(command, obj=false)
  @commands[command] = obj
end

#run(args, build_args = nil)

Run the command specified by args.

[ GitHub ]

  
# File 'lib/rubygems/command_manager.rb', line 147

def run(args, build_args=nil)
  process_args(args, build_args)
rescue StandardError, Timeout::Error => ex
  alert_error clean_text("While executing gem ... (#{ex.class})\n    #{ex}")
  ui.backtrace ex

  terminate_interaction(1)
rescue Interrupt
  alert_error clean_text("Interrupted")
  terminate_interaction(1)
end

#unregister_command(command)

Unregister the Symbol command as a gem command.

[ GitHub ]

  
# File 'lib/rubygems/command_manager.rb', line 124

def unregister_command(command)
  @commands.delete command
end