App::Cmd - write command line apps with less suffering


version 0.013


in yourcmd:

  use YourApp::Cmd;

in YourApp/

  package YourApp::Cmd;
  use base qw(App::Cmd);

in YourApp/Cmd/Command/

  package YourApp::Cmd::Command::blort;
  use base qw(App::Cmd::Command);
  use strict; use warnings;

  sub opt_spec {
    return (
      [ "blortex|X",  "use the blortex algorithm" ],
      [ "recheck|r",  "recheck all results"       ],

  sub validate_args {
    my ($self, $opt, $args) = @_;

    # no args allowed but options!
    $self->usage_error("No args allowed") if @$args;

  sub run {
    my ($self, $opt, $args) = @_;

    my $result = $opt->{blortex} ? blortex() : blort();

    recheck($result) if $opt->{recheck};

    print $result;

and, finally, at the command line:

  knight!rjbs$ yourcmd blort --recheck

  All blorts successful.


App::Cmd is intended to make it easy to write complex command-line applications without having to think about most of the annoying things usually involved.

For information on how to start using App::Cmd, see App::Cmd::Tutorial.



  my $cmd = App::Cmd->new(\%arg);

This method returns a new App::Cmd object. During initialization, command plugins will be loaded.

Valid arguments are:

  no_commands_plugin - if true, the command list plugin is not added

  no_help_plugin     - if true, the help plugin is not added

  plugin_search_path - The path to search for commands in. Defaults to
                       results of plugin_search_path method

If no_commands_plugin is not given, App::Cmd::Command::commands will be required, and it will be registered to handle all of its command names not handled by other plugins.

If no_help_plugin is not given, App::Cmd::Command::help will be required, and it will be registered to handle all of its command names not handled by other plugins. Note: "help" is the default command, so if you do not load the default help plugin, you should provide our own or override the default_command method.



This method runs the application. If called the class, it will instantiate a new App::Cmd object to run.

It determines the requested command (generally by consuming the first command-line argument), finds the plugin to handle that command, parses the remaining arguments according to that plugin's rules, and runs the plugin.

It passes the contents of the global argument array (@ARGV) to "prepare_command", but @ARGV is not altered by running an App::Cmd.



  my $program_name = $app->arg0;

  my $full_program_name = $app->full_arg0;

These methods return the name of the program invoked to run this application. This is determined by inspecting $0 when the App::Cmd object is instantiated, so it's probably correct, but doing weird things with App::Cmd could lead to weird values from these methods.

If the program was run like this:

  knight!rjbs$ ~/bin/rpg dice 3d6

Then the methods return:

  arg0      - rpg
  full_arg0 - /Users/rjbs/bin/rpg

These values are captured when the App::Cmd object is created, so it is safe to assign to $0 later.


  my ($cmd, $opt, @args) = $app->prepare_command(@ARGV);

This method will load the plugin for the requested command, use its options to parse the command line arguments, and eventually return everything necessary to actually execute the command.


This method returns the name of the command to run if none is given on the command line. The default default is "help"


  $app->execute_command($cmd, \%opt, @args);

This method will invoke validate_args and then run on $cmd.


This method returns the plugin_search_path as set. The default implementation, if called on "YourApp::Cmd" will return "YourApp::Cmd::Command"

This is a method because it's fun to override it with, for example:

  use constant plugin_search_path => __PACKAGE__;


  if ($cmd->app->global_options->{verbose}) { ... }

This method returns the running application's global options as a hashref. If there are no options specified, an empty hashref is returend.



This method sets the global options.


  my @names = $cmd->command_names;

This returns the commands names which the App::Cmd object will handle.


  my @plugins = $cmd->command_plugins;

This method returns the package names of the plugins that implement the App::Cmd object's commands.


  my $plugin = $cmd->plugin_for($command);

This method returns the plugin (module) for the given command. If no plugin implements the command, it returns false.


  my ($command_name, $opt, @args) = $app->get_command(@args);

Process arguments and into a command name and (optional) global options.


  print $self->app->usage->text;

Returns the usage object for the global options.


The top level usage line. Looks something like

  "yourapp [options] <command>"


Returns an empty list. Can be overridden for pre-dispatch option processing. This is useful for flags like --verbose.


  $self->usage_error("Your mother!");

Used to die with nice usage output, during validate_args.


  • publish and bring in Log::Speak (simple quiet/verbose output)

  • publish and use our internal enhanced describe_options

  • publish and use our improved simple input routines


Copyright 2005-2006, (code (simply)). All rights reserved; App::Cmd and bundled code are free software, released under the same terms as perl itself.

App::Cmd was originally written as Rubric::CLI by Ricardo SIGNES in 2005. It was refactored extensively by Ricardo SIGNES and John Cappiello and released as App::Cmd in 2006. Yuval Kogman performed significant refactoring and other improvements on the code.