Questions tagged [ruby]

Ruby is a multi-platform open-source, dynamic object-oriented interpreted language. The [ruby] tag is for questions related to the Ruby language, including its syntax and its libraries. Ruby on Rails questions should be tagged with [ruby-on-rails].

The ruby tag is for questions related to the Ruby language, including its syntax and its libraries. Questions specifically about the Ruby on Rails framework should be tagged with ruby-on-rails in addition to ruby. Do not use this to tag ruby used in the Japanese language.

Ruby is an open-source dynamic object-oriented interpreted language that combines concepts from Perl, Smalltalk, and Lisp. It supports multiple programming paradigms including functional, object-oriented, and imperative. It also has a dynamic type system and automatic memory management; it is, therefore, similar in varying respects to Smalltalk, Python, Perl, Lisp, Dylan, and CLU. Ruby's primary purpose is to "help every programmer in the world to be productive, and to enjoy programming, and to be happy." Ruby focuses on simplicity and productivity.

Ruby was initially conceived on February 24, 1993, by Yukihiro Matsumoto ('Matz') and version 1.0 was released in 1996. Ruby's mindshare spiked around 2005 due to Ruby on Rails, an MVC (Model, View, Controller) framework for building web applications and usage continues to grow as of 2016 with Ruby continuing to find acceptance in the commercial marketplace. The current stable version is 3.2.0 (2022-12-25).

Documentation, Announcements, Issue Tracker

Ruby Programming Language
Official Issue tracker
Ruby Doc, Ruby Core API Documentation
Ruby Doc, Ruby Standard Library API Documentation
Security announcements for Ruby, Rails, RubyGems, Bundler, and more

Unofficial Reference

Implementations, Installers

Ruby version managers. chruby, rbenv, rvm, pik (Windows)
Ruby, the official implementation also known as Matz' Ruby Implementation (MRI), YARV-Ruby. Official Site, GitHub
JRuby, an implementation of Ruby on top of Java with access to the JVM
Rubinius, an implementation of Ruby supporting native OS threads and a core library written almost entirely in Ruby
Ruby Enterprise Edition (not maintained anymore), a branch of MRI Ruby made for efficiency
MacRuby, an implementation of Ruby on Apples Objective-C and Cocoa frameworks
MagLev an implementation on top of VMWare's GemStone virtual machine
IronRuby is an implementation of Ruby on top of Microsoft's .NET CLR/DLR platform
Cardinal is an implementation of Ruby for the Parrot Virtual Machine
Topaz is an implementation of Ruby written in Python, on top of RPython
RubyMotion is an implementation of Ruby to develop native iOS and OS X applications

Gems (Library)

Ruby Gems - The Standard Library
Ruby Toolbox - Ruby Gems categorization, ranking, and statistics
Awesome Ruby - A categorized collection of awesome Ruby libraries, tools, frameworks, and software. The essential Ruby to build modern Apps and Web Apps
Bundler - Manage your application's gem dependencies
DevKit - A windows toolkit that makes it easy to build and use native C/C++ extensions

Tools

repl.it - Online REPL
RSpec - A testing tool for Ruby
Minitest - A testing tool for Ruby
Rubular - A Ruby regular expression tool
Pry - REPL and debugger for Ruby
Rubocop - A Ruby linter and code formatter

Online Courses

Ruby for Beginners
Ruby Tutorial
Codeacademy - Learn the fundamentals of Ruby and dynamic programming
RubyMonk - Free, interactive tutorials
Learn Ruby The Hard Way - Free
Why's (Poignant) Guide to Ruby - Free
Pluralsight - Video Lessons, Coding Challenges, and Screencasts
Ruby Tapas - Video Lessons and Screencasts - A wide variety of intermediate to advanced Ruby concepts and techniques, as well as core object-oriented design principles
The Pragmatic Studio - Project Driven Online Courses
Web Application Architectures - Learn how to build and deploy modern web application architectures – applications that run over the Internet, in the "cloud," using a browser as the user interface. We're going to learn about web apps through the Ruby on Rails framework. Rails is a framework for creating web applications that are built on top of the Ruby programming language.
Flatiron School's Intro to Ruby - Free, introductory course with instructors available for help
The Odin Project - Free online curriculum for beginners.

Books

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228397 questions

votes

3 answers

RSpec: How could I use the array include matcher in the expect syntax

I use new RSpec syntax (expect instead of should) and I'd like to test if an array includes elements of another array. In the old syntax it would be: array1.should include(array2) In the new syntax I tried to write: expect(array1).to…

ruby unit-testing rspec

asked Feb 15 '13 at 07:59

mrzasa

22,895
11
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votes

2 answers

How to undefine class in Ruby?

Undefining a method in Ruby is pretty simple, I can just use undef METHOD_NAME. Is there anything similar for a class? I am on MRI 1.9.2. I have to undefine an ActiveRecord Model, run two lines of code, and restore the model back to its original…

ruby ruby-on-rails-3 activerecord

asked Jul 16 '12 at 11:43

Bhushan Lodha

6,824
7
62
100

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3 answers

Programmatically get the number of jobs in a Resque queue

I am interested in setting up a monitoring service that will page me whenever there are too many jobs in the Resque queue (I have about 6 queues, I'll have different numbers for each queue). I also want to setup a very similar monitoring service…

ruby-on-rails ruby redis resque

asked Jun 27 '12 at 21:52

randombits

47,058
76
251
433

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6 answers

Ruby run shell command in a specific directory

I know how to run a shell command in Ruby like: %x[#{cmd}] But, how do I specify a directory to run this command? Is there a similar way of shelling out, similar to subprocess.Popen in Python: subprocess.Popen(r'c:\mytool\tool.exe',…

ruby shell command

asked Apr 13 '12 at 20:31

icn

17,126
39
105
141

votes

3 answers

Relative path to your project directory

In my Ruby project I am using a mess of things like moving and editing files on several remote boxes and I really need something like a relative path to my root project directory. I have many processing folders which are used in many methods. Right…

ruby

asked Feb 23 '12 at 15:59

qwebek

votes

5 answers

Checking character length in ruby

I got stuck in another situation: our users enter a text to be stored in a variable. The condition for that text is it can be allowed to enter only 25 characters, Now I have to write a regular expression which will check the condition, kindly help…

ruby string

asked Jan 06 '12 at 05:18

Vijay Sali

1,030
2
14
32

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3 answers

Role does not exist and unable to create database when using PostgreSQL

I am using Heroku for my application and it requires PostgreSQL but you can still use SQLite3 for development. Since Heroku strongly advised against having 2 different databases I decided to change to PostgreSQL for development. I installed the gem…

ruby-on-rails ruby ruby-on-rails-3 postgresql

asked Dec 26 '11 at 22:05

LearningRoR

26,582
22
85
150

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3 answers

Understanding Ruby's load paths

I'm a little confused about why my project can't load the files it needs, it's a really simple project tree: processor/ bin/ lib/ processor.rb processor/ mapper.rb reducer.rb and my processor.rb file looks like require…

ruby

asked Jul 12 '11 at 21:22

JP Silvashy

46,977
48
149
227

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4 answers

Rails 3: yield/content_for with some default value?

Is there any way to detect if #content_for was actually applied to a yield scope in Rails? A classic example being something like: <%= yield :page_title %> If a template doesn't set that with <% content_for :page_title, "Something…

ruby-on-rails ruby yield

asked May 07 '11 at 16:06

d11wtq

34,788
19
120
195

votes

5 answers

If I have a hash in Ruby on Rails, is there a way to make it indifferent access?

If I already have a hash, can I make it so that h[:foo] h['foo'] are the same? (is this called indifferent access?) The details: I loaded this hash using the following in initializers but probably shouldn't make a difference: SETTINGS =…

ruby-on-rails ruby ruby-on-rails-3

asked May 02 '11 at 19:29

Sarah W

votes

3 answers

How can I run a command five times using Ruby?

How can I run a command five times in a row? For example: 5 * send_sms_to("xxx");

ruby ruby-on-rails-3

asked Apr 15 '11 at 14:27

donald

23,587
42
142
223

votes

13 answers

Lisp and Erlang Atoms, Ruby and Scheme Symbols. How useful are they?

How useful is the feature of having an atom data type in a programming language? A few programming languages have the concept of atom or symbol to represent a constant of sorts. There are a few differences among the languages I have come across…

ruby erlang scheme lisp

asked Feb 02 '11 at 13:00

Muhammad Alkarouri

23,884
19
66
101

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5 answers

Finding the session id in rails 3

How can I get the current session id in rails 3? I've tried the following with no luck: session[:session_id] session['session_id'] session[:id] session['id'] session.id session.session_id

ruby-on-rails ruby session

asked Jan 28 '11 at 04:27

Austin

3,860
3
23
25

votes

4 answers

Rubygems, Bundler and RVM confusion

I read "Relationships between Rubygems, Bundler, and RVM" before asking it again. Well, there are many questions like this, but people who answered say they work with Rubygems, RVM and Bundler, and they have not explained how each of these work in…

ruby-on-rails ruby rubygems bundler rvm

asked Jan 05 '11 at 12:41

Anand

10,310
24
90
135

votes

8 answers

Sum the value of array in hash

This is my array [{:amount=>10, :gl_acct_id=>1, :alt_amount=>20}, {:amount=>20, :gl_acct_id=>2 , :alt_amount=>30}] i want result [{:amount => 30}] or {:amount = 30} Any idea?

ruby hash

asked Sep 16 '10 at 15:08

krunal shah

16,089
25
97
143

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Questions tagged [ruby]

Documentation, Announcements, Issue Tracker

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