Introduction to Ethereum Survey Course
For more classroom teaching explanations, refer to open resources. Using what you have learned, create projects and complete the required content. The included features and requirements are as follows:
One: Install and run geth client
1. Download and install geth
First download geth: https://geth.ethereum.org/downloads/
Select path ↓
2. Configure environment variables
3. Run geth as shown in the following command:
Check out the geth command. Use geth version to view the geth version number to determine whether geth is successfully installed. As shown in the following command:
`geth version`
You can view the commands and related parameters supported by the geth tool through geth --help, which is convenient for later operations on geth.
As shown in the following command:
geth --help
The result of the operation is as follows:
Two: Build a geth alliance chain network and realize communication between multiple nodes
1. Initialize the genesis block
Add the genesis.json file in the root directory of geth, the code in genesis.json is as follows
{
"alloc": {
"0x63b47f8abf5d47c9a90bab0ce0c6222b6cb2808a": {
//使用账户1创建
"balance": "999000000000000000000"
}
},
"config":{
"chainId":10,
"homesteadBlock":0,
"eip155Block":0,
"eip158Block":0
},
"nonce":"0x0000000000000042",
"mixhash":"0x0000000000000000000000000000000000000000000000000000000000000000",
"difficulty": "0x2000",
"alloc": {
},
"coinbase":"0x0000000000000000000000000000000000000000",
"timestamp": "0x00",
"parentHash":"0x0000000000000000000000000000000000000000000000000000000000000000",
"extraData": "",
"gasLimit":"0xffffffff"
}
geth --datadir chain1 init genesis.jsonInitialize the genesis block using
geth --datadir chain1 init genesis.json
Start cmd in the geth installation directory, enter
geth --datadir chain1 --nodiscover console
Enter geth console mode, where chain1 is the account and block data directory
2. Build an alliance chain,
Win+R opens a second console and enters the following command. (command to initialize the genesis block)
geth --datadir ./data-init2/ init genesis.json
Start and enter the console. (Note that there is one more ipcdiable parameter here. If it is the same as the first console, an error will be reported: Erro starting protocol stack:Access is denied)
Create new accounts on the two consoles and record the addresses
Use eth.accountsthe command to view existing accounts, which are currently empty
personal.newAccount("root")Create 2 accounts using //root as password
Account 1: 0x134a886c1f30bd52febed873054de8b7ae7e92e5
Account 2: 0x751b26bf96544c6bc50c9290a0e64631f7a82ec1
Use eth.getBalancethe () command to view existing accounts, which are currently empty
1. View the peers of the node.
admin.peers
Let the two nodes establish a link by sharing the enode address.
admin.nodeInfo.enode
Copy the enode information of node 2, and execute the following command on the console of node 1.
admin.addPeer ("enode://0bd1b7da689dd574eae04d20484086a5c59d81981b927602ef745233a72eac3280ea1a193a41c24d05fae54ae9e78d4fd76b590ffc356c6786eb6f70b0e6b276@[::]:40404?discport=0")
When mining on console 1 miner.start(), we will find that such log information appears on the console of node 2, and the synchronization is successful
Check the amount of the coinbase address and find that there has been an increase.
Three: Use solidity to write smart contract programs and deploy them on the geth client
Compile a simple smart contract in remix
`pragma solidity ^0.4.18;`
`contract test{`
`function multiply(uint a)public view returns(uint d){`
`return a*7;`
`}`
`}
Compile the above code, and you can see the bytecode and ABI information in the compilation details
{
--
"object": "608060405234801561001057600080fd5b5060bb8061001f6000396000f300608060405260043610603f576000357c0100000000000000000000000000000000000000000000000000000000900463ffffffff168063c6888fa1146044575b600080fd5b348015604f57600080fd5b50606c600480360381019080803590602001909291905050506082565b6040518082815260200191505060405180910390f35b60006007820290509190505600a165627a7a723058209135a65fdddd7be677810243db99bc4cbe46fcf74ee4ce1a3a8cc7fdbab004ef0029",
--
}
ABI documents
[
{
"constant": true,
"inputs": [
{
"name": "a",
"type": "uint256"
}
],
"name": "multiply",
"outputs": [
{
"name": "d",
"type": "uint256"
}
],
"payable": false,
"stateMutability": "view",
"type": "function"
}
]
Create a contract object through ABI, then unlock the account we created before in cmd, and deploy the contract
contractInstance = myContract.new({data: bytecode,gas: 1000000, from: eth.coinbase}, function(e, contract){
if(!e){
if(!contract.address){
console.log("Contract transaction send: Transaction Hash: "+contract.transactionHash+" waiting to be mined...");
}else{
console.log("Contract mined! Address: "+contract.address);
console.log(contract);
}
}else{
console.log(e)
}
})
Four: Through the terminal operation, complete the contract function call (create an account and test the mining function
Use the first step code to create node 3, get the encode address and link to node 2
Unlock Node 3
Use node two to transfer money to node three
Send transfer order
eth.sendTransaction({from: "0x134a886c1f30bd52febed873054de8b7ae7e92e5", to: "0x0df12fd40b27405558103da6f6938eb8c257d", value: "74000000000000000"})
Query balance is
74
Five: The function of completing transactions between multiple nodes, and setting and estimating gas usage
set gas value
01337036)]
Use node two to transfer money to node three
Send transfer order
eth.sendTransaction({from: "0x134a886c1f30bd52febed873054de8b7ae7e92e5", to: "0x0df12fd40b27405558103da6f6938eb8c257d", value: "74000000000000000"})
Query balance is
74