text: var http = require('http');
  var incrementify = require('incrementify');
  var cdnDomain = 'http://3gimg.qq.com';
  
  function fetch(incData, callback) {
    var oldurl = cdnDomain + '/' + incData.oldfile;
    var message = '';
    var req = http.get(oldurl, function(res) {
      var txt = '';
      res.setEncoding('utf8');
      res.on('data', function(chunk) {
        txt += chunk;
      });
      res.on('end', function() {
  
        if (txt.indexOf('<title>404 Not Found</title>') !== -1) {
          message = 'file 404'.red;
        } else {
  
          var ret = incrementify.build(txt, incData.newfile, {
            oldfile_type: 'content',
            output: incData.incfile
          });
          message = ret.signal == 10 ? 'success'.green : 'error'.red;
        }
        callback(message);
      });
    });
    req.on('error', function(err) {
      message = 'error'.red;
      callback(message);
    });
  }
  
  module.exports = fetch;
  