Skip to main content

Featured post

8 Top AWS services before you learn read today

AWS provides various services. This post gives clear understanding on AWS top services. Not only for traditional services, it also offer services for Mobile  IoS and Android Os.

Aws Service catalog helps organizations to manage their IT services.
List of Top AWS  ServicesEC2LambdaS3DynamoDBIAMAmazon CognitioDevice FarmMobile analyticsSNS AWS EC2 Instance EC2: Amazon Elastic Compute Cloud (EC2) provides secure, scalable, on-demand hardware virtualization in the cloud.
Using Amazon EC2 eliminates the need to invest in server hardware up front so that users can focus on, develop, and deploy applications faster. 
EC2 instances come in various hardware configurations and include an operating system.

Lambda Function in AWS AWS Lambda lets users run snippets of code without provisioning an infrastructure. 
This service is billed on a pay-as-you-go model, with users only paying for the execution time of their lambda code. 
There is no charge when code is not running. Lambda code can be set up to…

Learn VI editor Commands today

I have given VI editor commands to use in Ubuntu operating system. You can practice using them for your benefit and you can complete your work quickly.
Ubuntu vi editor commands

To begin changing or adding to text with vi, you can enter Insert or Replace modes, as shown in the following list. When you enter Insert or Replace mode, the characters you type will appear in the text document (as opposed to being interpreted as commands).
Ubuntu Vi editor commands
Press the Esc key to exit to Normal mode after you are done inserting or replacing text.

List of VI Editor Commands..

i—Typed text appears before current character.

a—Typed text appears after current character.

o—Open a new line below current line to begin typing.

s—Erase current character and replace with new text.

c?—Replace ? with l, w, $, or c to change the current letter, word, end of line, or line.

r—Replace current character with the next one you type.

Shift+i—Typed text appears at the beginning of current line.

Shift+a—Typed text appears at the end of currenta line.

Shift+o—Open a new line above current line to begin typing.

Shift+s—Erase current line and enter new text.

Shift+c—Erase from cursor to end of line and enter new text.

Shift+r—Overwrite as you type from current character going forward.

The following list contains keys you type to delete or paste text.

x—Delete text under cursor.

d?—Replace ? with l, w, $, or d to cut the current letter, word, or end of line from cursor or entire line.

y?—Replace ? with l, w, or $ to copy (yank) the current letter, word, or end of line from cursor.

p—Pastes cut or yanked text after cursor.

Shift+x—Delete text to left of cursor.

Shift+d—Cut from cursor to end of line.

Shift+y—Yank current line .

Shift+p—Pastes cut or yanked text before cursor.

Save VI editor changes...

Press - Esc key


Press Enter

Your work will be saved.


The above commands useful to work with VI editor. You can complete your task quickly and saves lot of time.


Most Viewed

Hyperledger Fabric Real Interview Questions Read Today

I am practicing Hyperledger. This is one of the top listed blockchains. This architecture follows R3 Corda specifications. Sharing the interview questions with you that I have prepared for my interview.

Though Ethereum leads in the real-time applications. The latest Hyperledger version is now ready for production applications. It has now become stable for production applications.
The Hyperledger now backed by IBM. But, it is still an open source. These interview questions help you to read quickly. The below set of interview questions help you like a tutorial on Hyperledger fabric. Hyperledger Fabric Interview Questions1). What are Nodes?
In Hyperledger the communication entities are called Nodes.

2). What are the three different types of Nodes?
- Client Node
- Peer Node
- Order Node
The Client node initiates transactions. The peer node commits the transaction. The order node guarantees the delivery.

3). What is Channel?
A channel in Hyperledger is the subnet of the main blockchain. You c…