nodejs 循环获取从1到n的图片

for(var i = 1; i <= 69; i++) {
    var e = i;
    var url = "http://hichat.herokuapp.com/content/emoji/" + e + ".gif";//这里写图片的地址
    xz(i);
  }

  function xz(e) {
    http.get(url, function(res) {
      var imgData = "";

      res.setEncoding("binary"); //一定要设置response的编码为binary否则会下载下来的图片打不开

      res.on("data", function(chunk) {
        imgData += chunk;
      });

      res.on("end", function() {
        fs.writeFile(e + '.gif', imgData, "binary", function(err) {
          if(err) {
            console.log("down fail");
          }
          console.log("down success", e);
        });
      });
    });
  }