Rexx (Restructured Extended Executor) is designed to be a scripting language. Its goal is to make scripting as easy, fast, reliable, and error-free as possible. Many programming languages are designed for compatibility with older languages and are written for specific audiences or platforms. Rexx ignores extraneous objectives. It was designed from day one to be powerful, yet easy to use. It is also very helpful for developing small programs that perform various text file transformations. This is an introductory tutorial that covers the basics of Rexx and how to deal with its various components and sub-components.
Features of Rexx
Rexx as a programming language has the following key features −
The ability to route commands to multiple environments
The ability to support functions, procedures, and commands associated with a specific invoking environment.
A built-in stack, with the ability to interoperate with the host stack if there is one.
Small instruction set containing just two dozen instructions
Case-insensitive tokens, including variable names
Character string basis
Dynamic data typing, no declarations
No reserved keywords, except in the local context
No include file facilities
Arbitrary numerical precision
Decimal arithmetic, floating-point
A rich selection of built-in functions, especially string and word processing
Automatic storage management
Content addressable data structures
Straightforward access to system commands and facilities
Simple error handling, built-in tracing, and debugger
Few artificial limitations
Simplified I/O facilities
To choose a Region follow the below step:
1. Sign in to the AWS Management Console.
2. Choose a service to go to that service's console.
3. In the navigation bar, choose the name of the currently displayed Region. Then choose the Region to which you want to switch.
Step instructions for how to assess and monitor the health and proper function of the application:
1. Navigate to your Amazon EC2 console and verify that you're in the correct region.
2. Choose Instance and select your launched instance.
3. Select the server to display your metadata page and choose the Status checks tab at the bottom of the page to review if your status checks passed or failed.
To verify the installation, follow the below instructions
Step 1. Connect to SSH:
Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.
In the navigation pane, choose Instances.
Select the instance and choose Connect.
Choose SSH Client
Copy the SSH command and paste it into the terminal.
ssh ubuntu@publicIP -i [Path of key pair file]
If it shows an access denied message run the following command, then run the above command again to connect via ssh.
chmod 400 [Path of key pair file]
Once launched in the Amazon EC2 Service, please connect to the instance via an SSH client using the ec2-user with the key pair associated at launch. Once connected as the ec2-user user, you will be able to sudo to the root user.
Step 2. Verify the installation
Follow the steps to verify the Rexx installation.
1. Login with ssh.
2. Type the below command to check the version.
3. To check the version :
How to use Rexx in the terminal:
1. After connecting with ssh write the below command:
sudo vi hello.rexx
3. Paste the following code into the file:
say 'Hello, World!'
4. Then run the below command to execute the code:
The output "Hello, World" should appear in your terminal.
That's it! You have successfully printed "Hello, World!" using Rexx in the terminal.
5. After using the above command then verify written the below command mentioned below image:
To monitor and assess application functions:-
a. Navigate to your Amazon EC2 console and verify that you're in the correct region.
b. Choose Instances and select your launched instance.
c. Select the server to display your metadata page and choose the Status checks tab at the bottom of the page to review if your status checks passed or failed.
For detailed information on how to use this application please visit: https://www.tutorialspoint.com/rexx/index.htm
For detailed information about managing and requesting increased service please visit: https://docs.aws.amazon.com/general/latest/gr/aws_service_limits.html