Class: Gem::Command (Ruby 2.3.4)

In Files

  • rubygems/command.rb
  • rubygems/command_manager.rb
  • rubygems/commands/help_command.rb

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Gem::Command

Base class for all Gem commands. When creating a new gem command, define initialize, execute, arguments, defaults_str, description and usage (as appropriate). See the above mentioned methods for details.

A very good example to look at is Gem::Commands::ContentsCommand

Attributes

command[R]

The name of the command.

defaults[RW]

The default options for the command.

options[R]

The options for the command.

program_name[RW]

The name of the command for command-line invocation.

summary[RW]

A short description of the command.

Public Class Methods

add_common_option(*args, &handler) 
 
               # File rubygems/command.rb, line 63
def self.add_common_option(*args, &handler)
  Gem::Command.common_options << [args, handler]
end
add_specific_extra_args(cmd,args)

Add a list of extra arguments for the given command. args may be an array or a string to be split on white space.

 
               # File rubygems/command.rb, line 92
def self.add_specific_extra_args(cmd,args)
  args = args.split(/\s+/) if args.kind_of? String
  specific_extra_args_hash[cmd] = args
end
build_args()

Arguments used when building gems

 
               # File rubygems/command.rb, line 51
def self.build_args
  @build_args ||= []
end
build_args=(value) 
 
               # File rubygems/command.rb, line 55
def self.build_args=(value)
  @build_args = value
end
common_options() 
 
               # File rubygems/command.rb, line 59
def self.common_options
  @common_options ||= []
end
extra_args() 
 
               # File rubygems/command.rb, line 67
def self.extra_args
  @extra_args ||= []
end
extra_args=(value) 
 
               # File rubygems/command.rb, line 71
def self.extra_args=(value)
  case value
  when Array
    @extra_args = value
  when String
    @extra_args = value.split
  end
end
new(command, summary=nil, defaults={})

Initializes a generic gem command named command. summary is a short description displayed in `gem help commands`. defaults are the default options. Defaults should be mirrored in defaults_str, unless there are none.

When defining a new command subclass, use #add_option to add command-line switches.

Unhandled arguments (gem names, files, etc.) are left in options[:args].

 
               # File rubygems/command.rb, line 118
def initialize(command, summary=nil, defaults={})
  @command = command
  @summary = summary
  @program_name = "gem #{command}"
  @defaults = defaults
  @options = defaults.dup
  @option_groups = Hash.new { |h,k| h[k] = [] }
  @parser = nil
  @when_invoked = nil
end
specific_extra_args(cmd)

Return an array of extra arguments for the command. The extra arguments come from the gem configuration file read at program startup.

 
               # File rubygems/command.rb, line 84
def self.specific_extra_args(cmd)
  specific_extra_args_hash[cmd]
end
specific_extra_args_hash()

Accessor for the specific extra args hash (self initializing).

 
               # File rubygems/command.rb, line 100
def self.specific_extra_args_hash
  @specific_extra_args_hash ||= Hash.new do |h,k|
    h[k] = Array.new
  end
end

Public Instance Methods

add_extra_args(args)

Adds extra args from ~/.gemrc

 
               # File rubygems/command.rb, line 385
def add_extra_args(args)
  result = []

  s_extra = Gem::Command.specific_extra_args(@command)
  extra = Gem::Command.extra_args + s_extra

  until extra.empty? do
    ex = []
    ex << extra.shift
    ex << extra.shift if extra.first.to_s =~ /^[^-]/
    result << ex if handles?(ex)
  end

  result.flatten!
  result.concat(args)
  result
end
add_option(*opts)

Add a command-line option and handler to the command.

See OptionParser#make_switch for an explanation of opts.

handler will be called with two values, the value of the argument and the options hash.

If the first argument of #add_option is a Symbol, it’s used to group options in output. See `gem help list` for an example.

 
               # File rubygems/command.rb, line 335
def add_option(*opts, &handler) # :yields: value, options
  group_name = Symbol === opts.first ? opts.shift : :options

  @option_groups[group_name] << [opts, handler]
end
arguments()

Override to provide details of the arguments a command takes. It should return a left-justified string, one argument per line.

For example:

def usage
  "#{program_name} FILE [FILE ...]"
end

def arguments
  "FILE          name of file to find"
end

 
               # File rubygems/command.rb, line 245
def arguments
  ""
end
begins?(long, short)

True if long begins with the characters from short.

 
               # File rubygems/command.rb, line 132
def begins?(long, short)
  return false if short.nil?
  long[0, short.length] == short
end
defaults_str()

Override to display the default values of the command options. (similar to arguments, but displays the default values).

For example:

def defaults_str
  --no-gems-first --no-all
end
 
               # File rubygems/command.rb, line 259
def defaults_str
  ""
end
description()

Override to display a longer description of what this command does.

 
               # File rubygems/command.rb, line 266
def description
  nil
end
execute()

Override to provide command handling.

options will be filled in with your parsed options, unparsed options will be left in options[:args].

See also: get_all_gem_names, get_one_gem_name, get_one_optional_argument

 
               # File rubygems/command.rb, line 146
def execute
  raise Gem::Exception, "generic command has no actions"
end
get_all_gem_names()

Get all gem names from the command line.

 
               # File rubygems/command.rb, line 176
def get_all_gem_names
  args = options[:args]

  if args.nil? or args.empty? then
    raise Gem::CommandLineError,
          "Please specify at least one gem name (e.g. gem build GEMNAME)"
  end

  args.select { |arg| arg !~ /^-/ }
end
get_all_gem_names_and_versions()

Get all [gem, version] from the command line.

An argument in the form gem:ver is pull apart into the gen name and version, respectively.

 
               # File rubygems/command.rb, line 192
def get_all_gem_names_and_versions
  get_all_gem_names.map do |name|
    if /\A(.*):(#{Gem::Requirement::PATTERN_RAW})\z/ =~ name
      [$1, $2]
    else
      [name]
    end
  end
end
get_one_gem_name()

Get a single gem name from the command line. Fail if there is no gem name or if there is more than one gem name given.

 
               # File rubygems/command.rb, line 206
def get_one_gem_name
  args = options[:args]

  if args.nil? or args.empty? then
    raise Gem::CommandLineError,
          "Please specify a gem name on the command line (e.g. gem build GEMNAME)"
  end

  if args.size > 1 then
    raise Gem::CommandLineError,
          "Too many gem names (#{args.join(', ')}); please specify only one"
  end

  args.first
end
get_one_optional_argument()

Get a single optional argument from the command line. If more than one argument is given, return only the first. Return nil if none are given.

 
               # File rubygems/command.rb, line 226
def get_one_optional_argument
  args = options[:args] || []
  args.first
end
handle_options(args)

Handle the given list of arguments by parsing them and recording the results.

 
               # File rubygems/command.rb, line 375
def handle_options(args)
  args = add_extra_args(args)
  @options = Marshal.load Marshal.dump @defaults # deep copy
  parser.parse!(args)
  @options[:args] = args
end
handles?(args)

True if the command handles the given argument list.

 
               # File rubygems/command.rb, line 362
def handles?(args)
  begin
    parser.parse!(args.dup)
    return true
  rescue
    return false
  end
end
invoke(*args)

Invoke the command with the given list of arguments.

 
               # File rubygems/command.rb, line 290
def invoke(*args)
  invoke_with_build_args args, nil
end
invoke_with_build_args(args, build_args)

Invoke the command with the given list of normal arguments and additional build arguments.

 
               # File rubygems/command.rb, line 298
def invoke_with_build_args(args, build_args)
  handle_options args

  options[:build_args] = build_args

  if options[:help] then
    show_help
  elsif @when_invoked then
    @when_invoked.call options
  else
    execute
  end
end
merge_options(new_options)

Merge a set of command options with the set of default options (without modifying the default option hash).

 
               # File rubygems/command.rb, line 354
def merge_options(new_options)
  @options = @defaults.clone
  new_options.each do |k,v| @options[k] = v end
end
remove_option(name)

Remove previously defined command-line argument name.

 
               # File rubygems/command.rb, line 344
def remove_option(name)
  @option_groups.each do |_, option_list|
    option_list.reject! { |args, _| args.any? { |x| x =~ /^#{name}/ } }
  end
end
show_help()

Display the help message for the command.

 
               # File rubygems/command.rb, line 282
def show_help
  parser.program_name = usage
  say parser
end
show_lookup_failure(gem_name, version, errors, domain)

Display to the user that a gem couldn’t be found and reasons why

 
               # File rubygems/command.rb, line 155
def show_lookup_failure(gem_name, version, errors, domain)
  if errors and !errors.empty?
    msg = "Could not find a valid gem '#{gem_name}' (#{version}), here is why:\n".dup
    errors.each { |x| msg << "          #{x.wordy}\n" }
    alert_error msg
  else
    alert_error "Could not find a valid gem '#{gem_name}' (#{version}) in any repository"
  end

  unless domain == :local then # HACK
    suggestions = Gem::SpecFetcher.fetcher.suggest_gems_from_name gem_name

    unless suggestions.empty?
      alert_error "Possible alternatives: #{suggestions.join(", ")}"
    end
  end
end
usage()

Override to display the usage for an individual gem command.

The text “[options]” is automatically appended to the usage text.

 
               # File rubygems/command.rb, line 275
def usage
  program_name
end
when_invoked(&block)

Call the given block when invoked.

Normal command invocations just executes the execute method of the command. Specifying an invocation block allows the test methods to override the normal action of a command to determine that it has been invoked correctly.

 
               # File rubygems/command.rb, line 320
def when_invoked(&block)
  @when_invoked = block
end

Private Instance Methods

wrap(text, width)

Wraps text to width

 
               # File rubygems/command.rb, line 501
def wrap(text, width) # :doc:
  text.gsub(/(.{1,#{width}})( +|$\n?)|(.{1,#{width}})/, "\\1\\3\n")
end