If you want to display only a list of directories, enter the following command on the console.

ls -l | grep '^d'

If you want to show just a list of files, type the following command on the console.

ls -l | grep -v '^d'

sudo yum install gitk

I tried it in Ubuntu 14.04.2 LTS, and it is working fine

Step 1: (the purpose of the first line in designating which interpreter to use for the rest of the file), and save the file as a hello-world.rb

#!/usr/bin/env ruby
puts "Hello World!"

Step 2: (make the file executable with the below command)

chmod u+x... 

You can do a two-way

First way

There is a “Computer” icon on the Desktop, right-click on that and select “Properties”, see image below

So, the System Properties Dialog will be open, and you can see under th...

Open Command Prompt with administrator privileges. Please refer to the image below for more details. Right-click on Command Prompt and select Run as administrator.

...

• A model just generates the model. Scaffold generates a controller and views, too.

./script/generate model mymodelname

• creates an ActiveRecord model that is typically connected to a database, but doesn't have to be.

./script/generate scaffold scaffoldname</pre... 

• Rails starts its web server on port 3000 by default. If you want to use a different port, such as 8888, run the command below.

ruby script/server -p 8888

SQL (Structured Query Language) categories in three languages

1. Data Definition Language (DDL)

Which is also known for Data Description Language used for specifying the database schema, like as creating, modifying, and destroying tables, views, indices, and stored procedures

• A CREATE statement (example of Create Table)...

• Open http://nodejs.org/, then click on Download (http://nodejs.org/download/), so you can view the following details on the screen.
  <img src="https://s3.amazonaw...

Ruby - String Class

• If you have multiple Rails versions installed on your application, and if you want to create a Rails application using the command below

rails demo_apps

• In this case, it will create a Rails application "apps" with the latest version installed on our machine.

• If y...

<% .... %> is Scriptlet 

and

<%= ... %> is Expression 

• To rollback your most recent migration, execute the command below

rake db:migrate:rollback

• If you want to rollback a specific migration, you need to execute the command below

rake db:migrate VERSION=

In Ruby 2.4.0, the Fixnum and Bignum classes were merged into Integer, resolving a long-standing issue.

• Fixnum for small integers (range depends on implementation, usually limited to machine word size)

• Bignum for larger integers (arbitrary precision)

Let’s see this in action.

Ruby 2.3.3

<code class="h...