concat.js

/**
 You will be given text on process.stdin. Buffer the text and reverse it using
 the `concat-stream` module before writing it to stdout.

 `concat-stream` is a write stream that you can pass a callback to to get the
 complete contents of a stream as a single buffer. Here's an example that uses
 concat to buffer POST content in order to JSON.parse() the submitted data:

 var concat = require('concat-stream');
 var http = require('http');

 var server = http.createServer(function (req, res) {
        if (req.method === 'POST') {
            req.pipe(concat(function (body) {
                var obj = JSON.parse(body);
                res.end(Object.keys(obj).join('\n'));
            }));
        }
        else res.end();
    });
 server.listen(5000);

 In your adventure you'll only need to buffer input with `concat()` from
 process.stdin.

 */


var concat = require('concat-stream');

process.stdin.pipe(concat(function(data) {
	   console.log( data.toString().split("").reverse().join(""));
}));