class 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) click to toggle source

# File lib/rubygems/command.rb, line 62
def self.add_common_option(*args, &handler)
  Gem::Command.common_options << [args, handler]
end

add_specific_extra_args(cmd,args) click to toggle source

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 lib/rubygems/command.rb, line 91
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() click to toggle source

Arguments used when building gems

# File lib/rubygems/command.rb, line 50
def self.build_args
  @build_args ||= []
end

build_args=(value) click to toggle source

# File lib/rubygems/command.rb, line 54
def self.build_args=(value)
  @build_args = value
end

common_options() click to toggle source

# File lib/rubygems/command.rb, line 58
def self.common_options
  @common_options ||= []
end

extra_args() click to toggle source

# File lib/rubygems/command.rb, line 66
def self.extra_args
  @extra_args ||= []
end

extra_args=(value) click to toggle source

# File lib/rubygems/command.rb, line 70
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={}) click to toggle source

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 lib/rubygems/command.rb, line 117
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) click to toggle source

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

# File lib/rubygems/command.rb, line 83
def self.specific_extra_args(cmd)
  specific_extra_args_hash[cmd]
end

specific_extra_args_hash() click to toggle source

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

# File lib/rubygems/command.rb, line 99
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) click to toggle source

Adds extra args from ~/.gemrc

# File lib/rubygems/command.rb, line 384
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) { |value, options| ... } click to toggle source

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 lib/rubygems/command.rb, line 334
def add_option(*opts, &handler) # :yields: value, options
  group_name = Symbol === opts.first ? opts.shift : :options

  @option_groups[group_name] << [opts, handler]
end

arguments() click to toggle source

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 lib/rubygems/command.rb, line 244
def arguments
  ""
end

begins?(long, short) click to toggle source

True if long begins with the characters from short.

# File lib/rubygems/command.rb, line 131
def begins?(long, short)
  return false if short.nil?
  long[0, short.length] == short
end

defaults_str() click to toggle source

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 lib/rubygems/command.rb, line 258
def defaults_str
  ""
end

description() click to toggle source

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

# File lib/rubygems/command.rb, line 265
def description
  nil
end

execute() click to toggle source

Override to provide command handling.

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

# File lib/rubygems/command.rb, line 145
def execute
  raise Gem::Exception, "generic command has no actions"
end

get_all_gem_names() click to toggle source

Get all gem names from the command line.

# File lib/rubygems/command.rb, line 175
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() click to toggle source

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 lib/rubygems/command.rb, line 191
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() click to toggle source

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 lib/rubygems/command.rb, line 205
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() click to toggle source

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 lib/rubygems/command.rb, line 225
def get_one_optional_argument
  args = options[:args] || []
  args.first
end

handle_options(args) click to toggle source

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

# File lib/rubygems/command.rb, line 374
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) click to toggle source

True if the command handles the given argument list.

# File lib/rubygems/command.rb, line 361
def handles?(args)
  begin
    parser.parse!(args.dup)
    return true
  rescue
    return false
  end
end

invoke(*args) click to toggle source

Invoke the command with the given list of arguments.

# File lib/rubygems/command.rb, line 289
def invoke(*args)
  invoke_with_build_args args, nil
end

invoke_with_build_args(args, build_args) click to toggle source

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

# File lib/rubygems/command.rb, line 297
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) click to toggle source

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

# File lib/rubygems/command.rb, line 353
def merge_options(new_options)
  @options = @defaults.clone
  new_options.each do |k,v| @options[k] = v end
end

remove_option(name) click to toggle source

Remove previously defined command-line argument name.

# File lib/rubygems/command.rb, line 343
def remove_option(name)
  @option_groups.each do |_, option_list|
    option_list.reject! { |args, _| args.any? { |x| x =~ /^#{name}/ } }
  end
end

show_help() click to toggle source

Display the help message for the command.

# File lib/rubygems/command.rb, line 281
def show_help
  parser.program_name = usage
  say parser
end

show_lookup_failure(gem_name, version, errors, domain) click to toggle source

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

# File lib/rubygems/command.rb, line 154
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"
    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() click to toggle source

Override to display the usage for an individual gem command.

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

# File lib/rubygems/command.rb, line 274
def usage
  program_name
end

when_invoked(&block) click to toggle source

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 lib/rubygems/command.rb, line 319
def when_invoked(&block)
  @when_invoked = block
end

Private Instance Methods

wrap(text, width) click to toggle source

Wraps text to width

# File lib/rubygems/command.rb, line 500
def wrap(text, width) # :doc:
  text.gsub(/(.{1,#{width}})( +|$\n?)|(.{1,#{width}})/, "\\1\\3\n")
end