1.js

var http = require('http')
var fs = require('fs')
require('bufferjs');
var spawn = require('child_process').spawn

var PicFile ='c:\\ocr\\ocr.bin'
var ResFilePrefix = 'c:\\ocr\\output'
var ResFile = ResFilePrefix + ".txt"


http.createServer(function (req, res) {

  var body = new Buffer(0);

  req.on('data', function (chunk) {
    body = Buffer.concat(body, chunk)
  });

  req.on('end', function () {
    fs.writeFileSync(PicFile, body)
    var ocr = spawn('tesseract', [PicFile, ResFilePrefix, '-l', 'yan']);
    ocr.on('exit', function (code) {
      console.log('child process exited with code ' + code);

      if (code!=0) {
        res.end("ocr returned 0") 
        return
      }

    var str = fs.readFileSync(ResFile).toString().trim()
    res.writeHead(200);  		
    if (str=="") {
      res.end("ocr returned an empty string")
      return
    }    

    try {
      var ev = eval(str)
      var output = "output: " + ev      
      res.end(output) 	
      }
      catch (ex) {
        res.end("exception during evaluation: " + ex)
      }    	
    });
    
  });
}).listen(8080);

console.log('Server running at http://127.0.0.1:8080/');