Month: February 2019

C++ sizeof Operator

Posted on Updated on

sizeof is a keyword and a compile-time operator that determines the size of given variable OR data-type, and returns result in bytes.

We can also use sizeof keyword to get size of classes, structures, unions and any other user defined data type.


sizeof ( data type)

to get the size of given datatype. like: sizeof(int)


sizeof (variable name)

Example program:

#include <iostream>
using namespace std;

int main() {
cout << "Size of char : " << sizeof(char) << endl;
cout << "Size of int : " << sizeof(int) << endl;
cout << "Size of short int : " << sizeof(short int) << endl;
cout << "Size of long int : " << sizeof(long int) << endl;
cout << "Size of float : " << sizeof(float) << endl;
cout << "Size of double : " << sizeof(double) << endl;
cout << "Size of wchar_t : " << sizeof(wchar_t) << endl;

return 0;

Blockchain from Bitcoin’s perspective

Posted on Updated on

Blockchain technology is used as basis for a secure and transparent distributed ledger for the Bitcoin cryptocurrency. Its decentralized, public and immutable properties solve the double spending problem and allow every participant of the network to read the transaction history, help in
the validation process and pay and receive Bitcoin.

Cryptographically complex math ensures that everyone can do transactions with everyone without the need for a trusted third party. Next to financial transactions, this also holds for other claims. Entities can put claims on a decentralized ledger by digitally signing it, which allows any other entity to verify that these claims are made by that specific entity.

What is CURL ?

Posted on Updated on

cURL is basically a Client URL Library or a Command line tool, can be considered as a non-interactive web browser which is used to move data to or from server which supports various protocols such as:

cURL allows users to perform multiple files download / uploads with a single command. Multiple URLs can be specified in single command and they will be fetched in given order. It also supports proxy details, file uploads via FTP, sending requests over HTTP protocol, establishing connections via SSL, getting and setting cookies, user and password authentication, SMTP authentication and sending emails, authentication via POP3 and IMAP and many more. Simply, cURL can be used for everything that is related to data transfer using Internet protocols.

Install Hyperledger Fabric on Ubuntu 18.04.1 – Step by Step

Posted on Updated on

Installation of Hyperledger Fabric on Ubuntu is very straight forward and is a step-by-step process. We can majorly divide this whole process into two major parts: First we need to install all pre-requisites and then we proceed towards installation of Fabric itself.

Installing Prerequisites for Hyperledger Fabric:

  • CURL
  • GO Programming Language with setup of path variable
  • Docker & Docker Compose
  • Node.js Runtime & NPM
To install all these prerequisites run following commands in terminal window one by one, everything should go smooth.

sudo apt-get install curl
sudo apt-get install golang-go
export GOPATH=$HOME/go
export PATH=$PATH:$GOPATH/bin
sudo apt-get install nodejs
sudo apt-get install npm
sudo apt-get install python
sudo apt-get install docker
curl -fsSL | sudo apt-key add -
sudo add-apt-repository "deb [arch=amd64] $(lsb_release -cs) stable"
sudo apt-get update
apt-cache policy docker-ce
sudo apt-get install -y docker-ce
sudo apt-get install docker-compose
sudo apt-get upgrade

Till now the environment is ready to install Hyperledger Fabric, Now we will download fabric samples. To do that run following commands in terminal one by one…

sudo curl -sSL | sudo bash -s 1.1.0
sudo chmod 777 -R fabric-samples

Now go into first-network directory which is inside fabric-samples folder and then we will run generate script that will create certificates and keys for the entities on our first blockchain network. This will also create genesis block (first block on blockchain)

cd fabric-samples/first-network
sudo ./ generate

Bring your first network up by running following command. byfn stands for “Build Your First Network”

sudo ./ up

If everything works fine you should see start screen of fabric network. To bring network down following command is used.
sudo ./ down

Installing SQL Server Management Studio

Posted on Updated on

Installing SQL Server Management Studio and connecting with Database

Installing SQL Server 2017

Posted on Updated on

Learn to Install SQL Server 2017 in your local computer