Ruby Tutorial

• Ruby Tutorial
• Ruby Environment
• Ruby Installation in Linux
• Ruby Installation in Windows
• Ruby Command Line
• Ruby Environment Variables
• Ruby Syntax
• Ruby Data Types
• Ruby Classes And Objects
• Ruby Class Case
• Ruby Variables
• Ruby Operators
• Ruby Comments
• Ruby Conditional Statements
• Ruby Loop
• Ruby Method
• Ruby Block
• Ruby Module
• Ruby String
• Ruby Array
• Ruby Hash
• Ruby Date & Time
• Ruby Range
• Ruby Iterators
• Ruby File Input and Output
• Ruby File Class and Methods
• Ruby Dir Class and Methods
• Ruby Exceptions

Ruby CGI

• Ruby CGI Programming
• Ruby CGI Method
• Ruby CGI Cookie
• Ruby CGI Session

Ruby Advanced

• Ruby Object Orientation
• Ruby Regular Expressions
• Ruby Database Access – DBI Tutorial
• Ruby Connection To Mysql – MySql2
• Ruby Send Mail – SMTP
• Ruby Socket Programming
• Ruby XML, XSLT and XPath Tutorial
• Ruby eb Service Application – SOAP4R
• Ruby Multithreading
• Ruby JSON
• Ruby RubyGems

Ruby Environment

In Ruby, like in many programming languages, an "environment" refers to the context in which a program runs. This context includes things like environment variables, the current directory, command-line arguments, and loaded libraries.

Here's a brief overview of some important aspects of the Ruby environment:

1. Environment Variables:

Environment variables are global settings that affect your system's behavior. In Ruby, you can access environment variables through the ENV object:

puts ENV['PATH'] # Prints the PATH environment variable

You can also set environment variables for the duration of your program:

ENV['MY_VARIABLE'] = 'my value'
puts ENV['MY_VARIABLE'] # Prints "my value"

2. Current Directory:

The current directory is the directory from which your Ruby script is being run. You can get the current directory with Dir.pwd:

puts Dir.pwd # Prints the current directory

You can also change the current directory with Dir.chdir:

Dir.chdir('/path/to/new/directory')
puts Dir.pwd # Prints the new directory

3. Command-Line Arguments:

Command-line arguments are inputs that you can pass to your Ruby script from the command line. These are accessible through the ARGV array:

# Suppose you run: ruby my_script.rb arg1 arg2
puts ARGV[0] # Prints "arg1"
puts ARGV[1] # Prints "arg2"

4. Loaded Libraries:

In Ruby, you can load libraries (also known as gems) with require:

require 'json' # Loads the json library

The $LOAD_PATH (or $:) variable contains the list of directories that Ruby will check when you call require. If you're developing a library, you might need to add its directory to $LOAD_PATH.

5. Ruby Version:

The RUBY_VERSION constant contains the version of Ruby that's currently running:

puts RUBY_VERSION # Prints the Ruby version, e.g. "2.7.1"

Remember, the environment in which your Ruby script runs can greatly affect its behavior. It's often important to control this environment to ensure that your script works as expected.

1. Ruby environment variables:

   • Description: Environment variables are key-value pairs that can be used to configure and control the behavior of Ruby applications.
   • Code example:

     # Accessing an environment variable
     puts ENV['MY_VARIABLE']
     

2. Managing Ruby gems in the environment:

   • Description: Use the gem command to manage Ruby gems, which are packages or libraries.
   • Code example:

     # Install a gem
     gem install my_gem
     
     # List installed gems
     gem list
     
     # Remove a gem
     gem uninstall my_gem
     

3. Managing dependencies in Ruby environment:

   • Description: Use a tool like Bundler to manage and install project dependencies.
   • Code example:

     # Gemfile
     source 'https://rubygems.org'
     gem 'my_gem', '~> 1.0'
     

     # Install dependencies
     bundle install
     

4. Ruby environment path:

   • Description: The PATH environment variable specifies the directories where executable files are located.
   • Code example:

     # Add Ruby binaries to the PATH
     export PATH="$PATH:/path/to/ruby/bin"