Class: Cmd

Inherits:
Object
  • Object
show all
Extended by:
ClassMethods
Includes:
ClassMethods
Defined in:
lib/cmd.rb

Overview

A simple framework for writing line-oriented command interpreters, based heavily on Python’s cmd.py.

These are often useful for test harnesses, administrative tools, and prototypes that will later be wrapped in a more sophisticated interface.

A Cmd instance or subclass instance is a line-oriented interpreter framework. There is no good reason to instantiate Cmd itself; rather, it’s useful as a superclass of an interpreter class you define yourself in order to inherit Cmd’s methods and encapsulate action methods.

Direct Known Subclasses

TarkinSh

Defined Under Namespace

Modules: ClassMethods

Class Attribute Summary collapse

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods included from ClassMethods

custom_exception_handlers, define_collect_method, doc, docs, handle, prompt, prompt_with, shortcut, shortcut_table, shortcuts

Constructor Details

#initialize ⇒ Cmd

Returns a new instance of Cmd.



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# File 'lib/cmd.rb', line 147

def initialize
  @stdin, @stdout = STDIN, STDOUT
  @stop = false
  setup
end

Class Attribute Details

.hide_undocumented_commands ⇒ Object

Flag that sets whether undocumented commands are listed in the help



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# File 'lib/cmd.rb', line 129

def hide_undocumented_commands
  @hide_undocumented_commands
end

Instance Attribute Details

#current_command=(value) ⇒ Object

The current command



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# File 'lib/cmd.rb', line 143

def current_command=(value)
  @current_command = value
end

#stdin=(value) ⇒ Object (writeonly)

STDIN stream used



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# File 'lib/cmd.rb', line 137

def stdin=(value)
  @stdin = value
end

#stdout=(value) ⇒ Object (writeonly)

STDOUT stream used



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# File 'lib/cmd.rb', line 140

def stdout=(value)
  @stdout = value
end

Class Method Details

.run(intro = nil) ⇒ Object 



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# File 'lib/cmd.rb', line 131

def run(intro = nil)
  new.cmdloop(intro)
end

Instance Method Details

#cmdloop(intro = nil) ⇒ Object Also known as: run

Starts up the command loop



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# File 'lib/cmd.rb', line 154

def cmdloop(intro = nil)
  preloop
  write intro if intro
  begin
    set_completion_proc(:complete)
    begin
      execute_command
    # Catch ^C
    rescue Interrupt
      user_interrupt
    # I don't know why ZeroDivisionError isn't caught below...
    rescue ZeroDivisionError
      handle_all_remaining_exceptions(ZeroDivisionError)
    rescue => exception
      handle_all_remaining_exceptions(exception)
    end
  end until @stop
  postloop
end

#do_exit ⇒ Object 



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# File 'lib/cmd.rb', line 194

def do_exit; stoploop end

#do_help(command = nil) ⇒ Object 



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# File 'lib/cmd.rb', line 177

def do_help(command = nil)
  if command
    command = translate_shortcut(command)
    docs.include?(command) ? print_help(command) : no_help(command)
  else
    documented_commands.each {|cmd| print_help cmd}
    print_undocumented_commands if undocumented_commands?
  end
end

#no_help(command) ⇒ Object

Called when the command has no associated documentation, this could potentially mean that the command is non existant



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# File 'lib/cmd.rb', line 189

def no_help(command)
  write "No help for command '#{command}'"
end

#turn_off_readline ⇒ Object

Turns off readline even if it is supported



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# File 'lib/cmd.rb', line 197

def turn_off_readline
  @readline_supported = false
  self
end