optimus-prime
An option parsing yak shave. I blame python.
Usage
Options
Create a parser class:
class OptionClass
include OptimusPrime
attr_reader :name, :age
option :name, :age
end
options = OptionClass.new
puts "Name: " + options.name
puts "Age: " + options.age
Then run your program:
$ ruby option_class.rb --name Pat --age 22
Name: Pat
Age: 22
Prompting for options
If you specify a :prompt option, the user will be prompted for
a value if one isn't provided already:
class OptionPromptClass
include OptimusPrime
attr_reader :name
option :name, :prompt => 'Enter a name:'
end
options = OptionPromptClass.new
puts "Name: " + options.name
Then run your program:
$ ruby option_prompt_class.rb
Enter a name: # enter "Pat"
Name: Pat
You can also have options that don't need a value (flags):
class FlagsClass
include OptimusPrime
attr_reader :verbose
flag :verbose
end
options = FlagsClass.new
puts "Verbose: " + options.verbose ? 'Yes' : 'No'
Then run your program:
$ ruby flags_class.rb --verbose
Verbose: Yes
Commands
You can specify commands using command, then passing a block
which will get evaluated in the context of an instance of the class,
so it will have all option values available.
class Commands
include OptimusPrime
option :name, :age
command :show do
puts "Name: " + (@name || '(n/a)')
puts "Age: " + (@age || '(n/a)')
end
end
Commands.new
Then run your program:
$ ruby commands.rb show --name Pat
Name: Pat
Age: (n/a)
Commands with arguments
class CommandsWithArgs
include OptimusPrime
command :show do |name|
puts "Name: " + name
end
end
CommandsWithArgs.new
Then run your program:
$ ruby commands_with_args.rb show Pat
Name: Pat
Commands as methods
class CommandsAsMethods
include OptimusPrime
command :show
def show(name)
puts "Showing: " + name
end
end
CommandsAsMethods.new
Then run your program:
$ ruby commands_as_methods.rb show Pat
Showing: Pat
Help
Add comments below command declarations to generate help:
command :show do |name|
# Shows the name.
#
# USAGE
#
# $ ruby commands.rb show Pat
puts "Name: " + name
end
Running your program:
$ ruby commands.rb help show
Shows the name.
TODO
- Actually use
optparse. It's good for what it does.