let fs = require("fs");  
let path = require("path");  
  
// 递归创建目录 异步方法  
function mkdirs(dirname, callback) {  
    fs.exists(dirname, function (exists) {  
        if (exists) {  
            callback();  
        } else {  
            // console.log(path.dirname(dirname));  
            mkdirs(path.dirname(dirname), function () {  
                fs.mkdir(dirname, callback);  
                console.log('在' + path.dirname(dirname) + '目录创建' + dirname  +'目录');
            });  
        }  
    });  
}  
mkdirs('hello/a/b/c',() => {
    console.log('done');
})
// 递归创建目录 同步方法
function mkdirsSync(dirname) {
    if (fs.existsSync(dirname)) {
      return true;
    } else {
      if (mkdirsSync(path.dirname(dirname))) {
        fs.mkdirSync(dirname);
        return true;
      }
    }
}
// mkdirsSync('A/B/C/D');