Using Exiting Methods

To invoke an explicit exit, use one of the exiting methods:

• exit!
• error!
• help!
• version!

exit!

The exit! method is a general way to invoke an explicit exit.

With No Argument

Without arguments, exit! simply exits the command. The exit code is set to 0.

class Mytrue < Cli::Command
  def run
    exit!
  end
end

Mytrue.run

Output:

$ mytrue
$ echo $?
0

With an Error

If the error option is true, the exit code is set to 1.

class Myfalse < Cli::Command
  def run
    exit! error: true
  end
end

Myfalse.run

Output:

$ myfalse
$ echo $?
1

With an Exit Code

You can specify the exit code.

class Myfalse < Cli::Command
  def run
    exit! code: 1
  end
end

With a Message

You can specify a message text that is printed before a command exits.

class Bye < Cli::Command
  def run
    exit! message: "bye :)"
  end
end

Or simply:

class Bye < Cli::Command
  def run
    exit! "bye :)"
  end
end

If a specified exit code is other than 0, the message is printed to STDERR.

class DontSayGoodbye < Cli::Command
  class Options
    arg "greeting"
  end

  def run
    if /bye/ =~ args.greeting
      exit! ":(", error: true # to STDERR
    else
      exit! ":)" # to STDOUT
    end
  end
end

With a Help Message

If the help option is true, the command's help message will be printed.

class HelpOrNothing < Cli::Command
  class Options
    bool "-h", desc: "show this help"
  end

  def run
    exit! help: options.h?
  end
end

HelpOrNothing.run ARGV

Output:

$ help-or-nothing -h
help-or-nothing [OPTIONS]

Options:
  -h  show this help

If the message argument is specified, both the specified message and the help message will be printed.

class TheFriday < Cli::Command
  class Help
    header <<-EOS
    Don't execute it on Friday the 13th.
    EOS
  end

  def the_friday?
    Time.now.day == 13 && Time.now.friday?
  end

  def run
    exit! "YOU DO IT!!!", help: true, error: true if the_friday?
  end
end

STDERR may be written:

YOU DO IT!!!

the-friday

Don't execute it on Friday the 13th.

With at_exit Handlers

exit! internally calls the standard exit method. So you can make a combination of exit! and at_exit handlers.

class FinallySmile < Cli::Command
  def run
    puts ":("
    exit!
  end
end

at_exit { puts ":)" }

FinallySmile.run

Output:

$ finally-smile
:(
:)

error!

The error! method is similar to exit!, however the error option is true as default.

These lines are equivalent:

exit! error: true
exit! code: 1
error!
error! code: 1

help!

The help! method is similar to exit!, however the help option is true as default.

If the message argument is specified, the error option is true as default. So,

help! "See help!"

is equivalent to

exit! "See help!", help: true, error: true

not

exit! "See help!", help: true

version!

The version! method prints the command's version and exits. The exit code is 0.

class VersionOrNothing < Cli::Command
  version "1.0.0"

  class Options
    bool "-v"
  end

  def run
    version! if options.v?
  end
end

Output:

$ version-or-nothing -v
1.0.0