在CentOS5.6上安装Node.js（续）——编写程序验证安装

        在上一篇文章《在CentOS5.6上安装Node.js》中，只用简单的几步就完成了安装。虽然看起来安装都是成功的，但是实际如何就要求我们写一个程序来进行验证一下。由于最近也在学习MongoDB，所以就写一个读取MongoDB数据库：计算actionId为772的日志总数。

        1. 使用安装mongodb驱动

# npm install mongodb
npm WARN mongodb@0.9.6-23 package.json: bugs['web'] should probably be bugs['url']
npm WARN nodeunit@0.5.1 package.json: bugs['web'] should probably be bugs['url']

> mongodb@0.9.6-23 install /root/develop/node/node_modules/mongodb
> bash ./install.sh

================================================================================
=                                                                              =
=  To install with C++ bson parser do <npm install mongodb --mongodb:native>   =
=  the parser only works for node 0.4.X or lower                               =
=                                                                              =
================================================================================
Not building native library for cygwin
Using GNU make
mongodb@0.9.6-23 ./node_modules/mongodb

根据提示执行：

# cd node_modules/mongodb
# bash ./install.sh

   注意：驱动必须安装在项目所在的目录下，并不是安装一次所有项目都可以使用。

var http = require('http');
var mongodb = require('mongodb');

http.createServer(function(req, res){
  res.writeHead(200, {'Content-Type': 'text/plain;charset=utf-8'});
  mongodb.connect('mongodb://localhost:40202/log', function(err, conn){
    conn.collection('log', function(err, coll){
      coll.count({'action': 772}, function(err, count){
        res.write('The total of action 772 is ' + count + ".\n");
        res.end();
      });
    });
  });
}).listen(3000, '127.0.0.1');

console.log('Server running at http://127.0.0.1:3000/');

启动服务器：

# node mongo.js

参考文章：

Getting started with VMWare CloudFoundry, MongoDB and Node.js

Blog rolling with mongoDB, express and Node.js