node.js watch file

const fs = require('fs');

fs.watchFile('./test.txt', function (cur, pre) {
    if (!pre.isFile() && cur.isFile()) {
        console.log('==>file created');
    }
    else if (pre.isFile() && !cur.isFile()) {
        console.log('==>file deleted');
    }
    else if (pre.isFile() && cur.isFile() && Date.parse(pre.mtime) !== Date.parse(cur.mtime)) {
        console.log('==>file modified');
    }
});

//开始监视时test.txt必须存在
const watcher = fs.watch('./test.txt', function (event, filename) {
    // event为change或rename
    console.log(event, filename);
    if (event === 'rename') {
        console.log('文件不存在，监视停止');
        watcher.close();
    }
});