使用nodejs爬取前程无忧前端技能排行

/*使用fiddler抓包，需要配置lan代理，且设置如下参数*/
process.env.https_proxy = "http://127.0.0.1:8888";
process.env.http_proxy = "http://127.0.0.1:8888";
process.env.NODE_TLS_REJECT_UNAUTHORIZED = "0";
/*使用到的模块*/
var request = require('superagent');  //发送客户端请求
require('superagent-proxy')(request);  //使用代理发送请求
var cheerio = require('cheerio');    //以jq类似的方法操作返回的字符，不需要用正则
require('superagent-charset')(request);//node不支持gbk,gb2312,this will add request.Request.prototype.charset.
var async = require('async');      //异步流控制模块
var fs = require('fs');
/*相关参数，通过fiddler抓包后复制过来*/
var ws = fs.createWriteStream('res.html',{flags:'w '}); //a 追加的读写模式，w 覆盖
var loginUrl = "https://login.51job.com/login.php";
var searchUrl = "http://search.51job.com/jobsearch/search_result.php";
var queryStrings = "fromJs=1&jobarea=020000&keyword=前端开发&keywordtype=2&lang=c&stype=2&postchannel=0000&fromType=1&confirmdate=9";
var loginForms = {
  lang: 'c',
  action: 'save',
  from_domain: 'i',
  loginname: '***',  //自己的用户名和密码
  password: '***',
  verifycode: '',
  isread: 'on'
};
var searchForms = {
  lang: 'c',
  stype: '2',
  postchannel: '0000',
  fromType: '1',
  line: '',
  confirmdate: '9',
  from: '',
  keywordtype: '2',
  keyword: '前端开发',
  jobarea: '020000',
  industrytype: '',
  funtype: ''
};
var searchFormsString='lang=c&stype=2&postchannel=0000&fromType=1&line=&confirmdate=9&from=&keywordtype=2&keyword=ǰ