nodejs验证码生成与环境配置

首先安装系统：

sudo apt-get install libpangocairo-1.0-0 libcairo2-dev libgnomeui-dev libgstreamer0.10-dev libglib2.0-dev libjpeg-dev libgif-dev

然后再安装npm

npm install --save simple-captcha

var simpleCaptcha = require('simple-captcha');

  captcha: function(req, res) {
    var captcha = require('simple-captcha').create({width: 100, height: 40});
    req.session.captcha = captcha.text();
    console.log(req.session.captcha);
    captcha.generate();
    res.write(captcha.buffer('image/png'));
    res.end();
  }