node 图片验证码
var ccap = require('ccap')();//验证码
//获取验证码
exports.userCode = function(req, res){
if(res.url == '/favicon.ico')return res.end('');//Intercept request favicon.ico
var ary = ccap.get();
var txt = ary[0];
var buf = ary[1].toString('base64');
req.session.userCode = txt
res.json({pic:buf})
}