BernardK

BernardK

Programming Ruby 3.2 (5th Edition): B1.0 page 240, short option with/without space

@noelrappin

page 240, last paragraph, lines 5-7 : the short option can have a space

… … … … … … … … … … … … … … … … … … … … … There’s one slight bit of weirdness here, which is
that a required argument is separated from a long option by a space but is flush against a
short option, so -xTHING

From the doc and experimentation, the marker can be separated by a space from the short option (it MUST be separated from a long option).

parser.on('-x XXX' … or parser.on('-xXXX' … have the same effect.

require "optparse"

parser = OptionParser.new

parser.on('-x XXX', '--xxx', 'Required argument via short name') do |value|
  puts "option -x is '-x XXX'"
end

parser.on('-zZZZ', '--zzz', 'Required argument via short name') do |value|
  puts "option -z is '-zZZZ'"
end

parser.parse!
% ruby -w rubyworld/option_doc.rb --help
Usage: option_doc [options]
    -x, --xxx XXX                    Required argument via short name
    -z, --zzzZZZ                     Required argument via short name

% ruby -w rubyworld/option_doc.rb -x x
option -x is '-x XXX'
% ruby -w rubyworld/option_doc.rb -z x
option -z is '-zZZZ'

First Post!

noelrappin

noelrappin

Author of Modern Front-End Development for Rails

Interesting, I must have misinterpreted the documentation. Thanks!

Where Next?

Popular Pragmatic Bookshelf topics Top

mikecargal
Title: Hands-On Rust (Chap 8 (Adding a Heads Up Display) It looks like ​.with_simple_console_no_bg​(SCREEN_WIDTH*2, SCREEN_HEIGHT*2...
New
jdufour
Hello! On page xix of the preface, it says there is a community forum "… for help if your’re stuck on one of the exercises in this book… ...
New
raul
Page 28: It implements io.ReaderAt on the store type. Sorry if it’s a dumb question but was the io.ReaderAt supposed to be io.ReadAt? ...
New
gilesdotcodes
In case this helps anyone, I’ve had issues setting up the rails source code. Here were the solutions: In Gemfile, change gem 'rails' t...
New
New
leba0495
Hello! Thanks for the great book. I was attempting the Trie (chap 17) exercises and for number 4 the solution provided for the autocorre...
New
AufHe
I’m a newbie to Rails 7 and have hit an issue with the bin/Dev script mentioned on pages 112-113. Iteration A1 - Seeing the list of prod...
New
creminology
Skimming ahead, much of the following is explained in Chapter 3, but new readers (like me!) will hit a roadblock in Chapter 2 with their ...
New
New
New

Other popular topics Top

New
AstonJ
Curious to know which languages and frameworks you’re all thinking about learning next :upside_down_face: Perhaps if there’s enough peop...
New
AstonJ
I have seen the keycaps I want - they are due for a group-buy this week but won’t be delivered until October next year!!! :rofl: The Ser...
New
Exadra37
I am asking for any distro that only has the bare-bones to be able to get a shell in the server and then just install the packages as we ...
New
Exadra37
Oh just spent so much time on this to discover now that RancherOS is in end of life but Rancher is refusing to mark the Github repo as su...
New
PragmaticBookshelf
Build highly interactive applications without ever leaving Elixir, the way the experts do. Let LiveView take care of performance, scalabi...
New
AstonJ
Saw this on TikTok of all places! :lol: Anyone heard of them before? Lite:
New
PragmaticBookshelf
Author Spotlight Mike Riley @mriley This month, we turn the spotlight on Mike Riley, author of Portable Python Projects. Mike’s book ...
New
PragmaticBookshelf
Get the comprehensive, insider information you need for Rails 8 with the new edition of this award-winning classic. Sam Ruby @rubys ...
New
AstonJ
This is cool! DEEPSEEK-V3 ON M4 MAC: BLAZING FAST INFERENCE ON APPLE SILICON We just witnessed something incredible: the largest open-s...
New

Sub Categories: