test.js

var spawnSync = require('child_process').spawnSync;

var stdio = [
  { type: 'pipe', readable: true,  input: new Buffer('Fubar!') },
  { type: 'pipe', writable: true },
  { type: 'pipe', writable: true },
  { type: 'inherit', fd: 0 }
];

var options = {
  timeout: 1000,
  // -- maxBuffer is a minimum-value, not a precise limit: --
  maxBuffer: 12345,
  // cwd: '/some/where',
  // env: { some: 'key' }
  // stdio: stdio,
  // OR stdio: 'pipe',
  // OR stdio: ['pipe', 'inherit', ...],
  // -- This is a short-hand for setting stdio[0].input: --
  input: 'This gets echoed back. Aint that fun?',
  // uid: null,
  // gid: null,
  // windowsVerbatimArguments: true,
  // -- Encoding is applied to all inputs and outputs: --
  encoding: 'utf8'
}

var r = spawnSync('sh', ['-c', 'echo hello && cat'], options);
  
console.log(r);