自己用的空气指数实时图的爬虫 原

var http = require('http');
var fs = require('fs');
var cheerio = require('cheerio');
var request = require('request');

var url = "http://www.air-level.com/";
function fetchPage(x) {     //封装了一层函数
    request(x,function(error,response){
        var $ = cheerio.load(response.body); //采用cheerio模块解析html
            var time = $('.text-center h4').text().trim();
            var img_src = $('.text-center img').attr("src").trim();
            var filename=img_src.substr( img_src.lastIndexOf('/'))
            request(img_src).pipe(fs.createWriteStream('./image/' +filename));   
    })
}
fetchPage(url);      //主程序开始运行
setInterval(function(){
    fetchPage(url); 
},1000*60*30)
process.on('uncaughtException', function (err) {
  //打印出错误
  console.log(err);
  //打印出错误的调用栈方便调试
  console.log(err.stack);
});