I. Console Color Printing

Download console-color-mr

npm install console-color-mr --save-dev

The first usage:

Direct introduction of require('console-color-mr');

Modified the default color. console.info will output red directly

//use color
console.info('------------ default color--------');
console.info('info', 'fff'); //green text
console.warn('this is warn');//yellowBG text
console.error('this is error');//red text
console.debug('this is debug');//gray text
console.log('this is log','msg1'.red, 'msg2'.blue);
console.info('this is info','msg1'.red, 'msg2'.blue); //force change default color
console.info('----------------------------');

Use discoloration in variables or functions

console.group('---------variable use color------------');

let name = 'Michael';
let age  = 1000;

let obj = {
	name : 'michael',
	age  : '100'
};

function hello() {
	return 'hello';
}

function isBoole() {
	return true;
}

console.log(name);
console.log('Hello,My name is ' + name.green + ',I am a' + ' man'.yellow + '.');
console.log(age.blue);
console.log(obj.name.blue);
console.log(obj.name.greenBG);
console.log(hello().red);
//Boolean value must change to string.
console.log(isBoole().toString().red);

console.groupEnd();

The second usage:

After the first method is introduced, the original system object method will be modified. If you still want to use methods on system objects, save this reference with a variable.
let _console = require('console-color-mr');

_console.info('info');
_console.debug('debug');
_console.warn('warn');
_console.error('error');

style

'bold'

'italic'

'underline'

'inverse'

'strikethrough'

'white'

'grey'

'black'

'blue'

'cyan'

'green'

'magenta'

'red'

'yellow'

'whiteBG'

'greyBG'

'blackBG'

'blueBG'

'cyanBG'

'greenBG'

'magentaBG'

'redBG'

'yellowBG'

Reference link: https://blog.csdn.net/michael51/article/details/79035459

2. Implementing port and ip printing by koa (similar to vue)

1. Download os first

npm install os --save-dev

2. introduction

const os = require('os');

3. use

function getIPv4() {
	//The same interface may have more than one IP4v address, so use array storage
	let ipv4s = [];
	//Getting list objects of network interfaces
	let interfaces = os.networkInterfaces();
	Object.keys(interfaces).forEach(function(key) {
		interfaces[key].forEach(function(item) {
			//Skip IPv6 and'127.0.0.1'
			if ('IPv4' !== item.family || item.internal !== false) return;
			ipv4s.push(item.address); //Available ipv4s join arrays
			// console.log(key + '--' + item.address);
		})
	})
	return ipv4s[0]; //Return an available one.
}
let ipv4 = getIPv4();//LAN IP

Example:

const Koa = require('koa');
const app = new Koa();
// Ways of direct invocation
// const router = require('koa-router')();
// Or create router instances separately
const Router = require('koa-router');
const router = new Router();
const os = require('os');
const port = 3000;
require('console-color-mr');
//Get the local ipv4 address
function getIPv4() {
	//The same interface may have more than one IP4v address, so use array storage
	let ipv4s = [];
	//Getting list objects of network interfaces
	let interfaces = os.networkInterfaces();
	Object.keys(interfaces).forEach(function(key) {
		interfaces[key].forEach(function(item) {
			//Skip IPv6 and'127.0.0.1'
			if ('IPv4' !== item.family || item.internal !== false) return;
			ipv4s.push(item.address); //Available ipv4s join arrays
			// console.log(key + '--' + item.address);
		})
	})
	return ipv4s[0]; //Return one available
}
let ipv4 = getIPv4();
app.use(async (ctx, next) => {
	// ctx.body = 'Hello World';
	await next();
});
router.get('/home', async ctx => {
	ctx.body = 'Hello Router';
})
// Startup routing
app.use(router.routes()).use(router.allowedMethods())
// Above is the official recommendation. allowedMethods is used after routes to set response header based on ctx.status.
app.listen(port, () => {
	console.log('Listening at ' + 'http://localhost:'.green + port.green + '\n'.green + 'or at ' + 'http://'.green +
		ipv4.green + ':'.green + port.green)
});