npm install yargs --save

const yargs = require(‘yargs‘);

let argv = yargs.argv;
console.log(argv);

const yargs = require(‘yargs‘);

let argv = yargs.argv;
console.log(argv._);

const yargs = require(‘yargs‘);

let argv = yargs
    .alias(‘n‘, ‘name‘)
    .alias(‘s‘, ‘save‘)
    .alias(‘w‘, ‘width‘)
    .argv;

console.log(argv);

const yargs = require(‘yargs‘);

let argv = yargs
    .alias(‘s‘, ‘src‘)
    .alias(‘d‘, ‘dst‘)
    .demandOption([‘s‘, ‘d‘], ‘s 与 d 必须填写‘)
    .default(‘s‘, ‘a.txt‘)
    .default(‘d‘, ‘b.txt‘)
    .describe(‘s‘, ‘源文件‘)
    .describe(‘d‘, ‘目标文件‘)
    .argv;

console.log(argv);

const yargs = require(‘yargs‘);

let argv = yargs
    .option(‘s‘, {
        alias: ‘src‘,
        demandOption: true,
        default: ‘a.txt‘,
        describe: ‘源文件‘,
        type: ‘string‘
    })
    .option(‘d‘, {
        alias: ‘dst‘,
        demandOption: true,
        default: ‘b.txt‘,
        describe: ‘目标文件‘,
        type: ‘string‘
    })
    .argv;

console.log(argv);

const yargs = require(‘yargs‘);

let argv = yargs
    .alias(‘s‘, ‘save‘)
    .boolean([‘s‘])
    .argv;

console.log(argv);

const yargs = require(‘yargs‘);

let argv = yargs
    .alias(‘s‘, ‘save‘)
    .usage(‘Usage: --s <filename>‘)
    .example(‘--s a.txt‘, ‘设置源文件‘)
    .epilog(‘copyright‘)
    .help(‘info‘)
    .argv;

console.log(argv);