Book Image

Mastering Blockchain.. - Third Edition

By : Imran Bashir
Book Image

Mastering Blockchain.. - Third Edition

By: Imran Bashir

Overview of this book

Blockchain is the backbone of cryptocurrencies, with applications in finance, government, media, and other industries. With a legacy of providing technologists with executable insights, this new edition of Mastering Blockchain is thoroughly revised and updated to the latest blockchain research with four new chapters on consensus algorithms, Serenity (the update that will introduce Ethereum 2.0), tokenization, and enterprise blockchains. This book covers the basics, including blockchain’s technical underpinnings, cryptography and consensus protocols. It also provides you with expert knowledge on decentralization, decentralized application development on Ethereum, Bitcoin, alternative coins, smart contracts, alternative blockchains, and Hyperledger. Further, you will explore blockchain solutions beyond cryptocurrencies such as the Internet of Things with blockchain, enterprise blockchains, tokenization using blockchain, and consider the future scope of this fascinating and disruptive technology. By the end of this book, you will have gained a thorough comprehension of the various facets of blockchain and understand their potential in diverse real-world scenarios.
Table of Contents (24 chapters)
23
Index

Contract deployment

A simple contract can be deployed using Geth and interacted with using Web3 via the command-line interface (CLI) that geth provides (console or attach). The following are the steps to achieve that. As an example, the following source code will be used:

pragma solidity ^0.4.0;
contract valueChecker
{
    uint price=10;
    event valueEvent(bool returnValue);
    function Matcher (uint8 x) public returns (bool)
    {
        if (x>=price)
        {
            emit valueEvent(true);
            return true;
        }
    }
}

Run the geth client using the following command:

$ geth --datadir ~/etherprivate --networkid 786 --allow-insecure-unlock –rpc --rpcapi "web3,net,eth,debug,personal" --rpccorsdomain https://remix.ethereum.org --debug --vmdebug –nodiscover

or

$ geth --datadir ~/etherprivate --networkid 786 --allow-insecure-unlock --rpc --rpcapi "web3,net,eth,debug" --rpcport 8001 --rpccorsdomain &quot...