splicer.js

var co = require('co');
var split = require('split');
var thunk = require('thunkify');
var pipe = thunk(require('multipipe'));
var read = require('co-read');
var write = require('co-write');
var JSONStream = require('JSONStream');

co(function*(){
  var headerData = {};
  var splitter = split();

  yield [
    pipe(process.stdin, splitter),
    function*(){
      var line;
      while (line = (yield read(splitter)).toString('utf8')) {
        if (line === '') {
          yield write(process.stdout, JSON.stringify(headerData));
          yield pipe(
            splitter,
            JSONStream.parse(['rows', true]),
            JSONStream.stringify(),
            process.stdout
          );
          return;
        }

        var m = /^(\S+):(.+)/.exec(line);
        var key = m && m[1].trim();
        var value = m && m[2].trim();
        if (m) headerData[key] = value;
      }
    }
  ];
})(function(err){
  if (err) throw err;
});