/ruby_cli

Factors out code needed to create Ruby command line applications

Ruby CLI ↑

Author

Martin Velez

Copyright

Copyright © 2011 Martin Velez

License

Distributed under the same terms as Ruby

Description ↑

“RubyCLI” is a Ruby library which factors out the code needed to create Ruby programswith a command line interface (CLI) which follows the Unix Philosophy design method outlined in www.faqs.org/docs/artu/ch01s06.html.

Currently, RubyCLI is short and simple. It uses Ruby’s core optparse library.

Design ↑

What does a command line application library need to do?

  1. Provide a user interface (UI)

    • Process options (use Ruby’s Option Parser)

    • Process arguments

  2. Pass options and arguments as parameters to other functions defined in libraries or other executables.

What does a command line application library need not do? 1. A command line application does not need to validate options or arguments. Libraries or other executables should do this.

Installation ↑

gem install ruby_cli

Alternative Tools ↑

There are other tools out there which can be used to write command line applications.

  1. clamp

    • I don’t like to learn new DSLs

  2. optparse

    • This library uses this to parse options.

  3. Thor

    • It does not try to follow the Unix Philosophy.

  4. Clip

    • OptionParser already exists.

Usage ↑

  1. New File

  2. Require the ruby_cli gem.

  3. Create a Ruby class.

  4. Call it “App”, for example.

  5. Include the RubyCLI module.

  6. Define the command method.

* This is where your program does the actual work.

* At this point you have options and arguments available. * Pass them as parameters to library functions or as options/arguments to other executables. * Be smart! Have libraries and other executables do the heavy work.

* Be smart! Fewer lines of code (LOC) is good.

  1. Define command options and defaults (optional)

* This is where you define a hash for your options and set the default values. * Remember, options by definition are optional.

  1. Define command arguments and defaults (optional)

Usage Example ↑

This example demonstrates how to use RubyCLI to create a #!/usr/bin/ruby

require ‘ruby_cli’

class App include RubyCLI

def command puts “hello world” end

end

if __FILE__ == $0 app = App.new(ARGV) app.run end

Dependencies ↑

  • Ruby 1.8.7 or greater

Acknowledgements ↑

Todd Werth

  • I used his Ruby command line application skeleton code. I borrowed

some ideas from there.

TODO ↑

  • ?

Source Code ↑

github.com/martinvelez/ruby_cli