var http = require('http');var fs = require('fs'); function Mzitu(options) {  this.id = 1;     this.initialize.call(this, options);  return this;} Mzitu.prototype = {  constructor: Mzitu,  initialize: function _initialize(options) {    this.baseUrl = options.baseUrl;    this.dir = options.dir || '';    this.reg = options.reg;    this.total = options.total;    this.page = options.from || 1;  },  start: function _start() {    this.getPage();  },  getPage: function _getPage() {    var self = this,      data = null;     if (this.page <= this.total) {      http.get(this.baseUrl + this.page, function (res) {        res.setEncoding("utf8");         res.on('data', function (chunk) {          data += chunk;        }).on('end', function () {          self.parseData(data);        });      });    }  },  parseData: function _parseData(data) {    var res = [],      match;     while ((match = this.reg.exec(data)) != null) {      res.push(match[1]);    }     this.download(res);  },  download: function _download(resource) {    var self = this,      currentPage = self.page;     resource.forEach(function (src, idx) {      var filename = src.substring(src.lastIndexOf('/') + 1),        writestream = fs.createWriteStream(self.dir + filename);             http.get(src, function (res) {        res.pipe(writestream);      });       writestream.on('finish', function () {        console.log('page: ' + currentPage + ' id: ' + self.id++ + ' download: ' + filename);      });    });         self.page++;    self.getPage();  }};

var mzitu = new Mzitu({  baseUrl: 'http://www.mzitu.com/share/comment-page-',  dir: '',  reg: /<img/s*src="(.*?)"/s*alt=".*"/s*//>/g,  total: 141,  from: 1}); mzitu.start();