spawn.js

var sys   = require('sys'),
    spawn = require('child_process').spawn,
    openssl    = spawn('python', ['test.py']);
    
openssl.stdout.on('data', function (data) {+
  sys.print('signature is valid: ' + data);
});

openssl.stderr.on('data', function (data) {
  sys.print('Error: ' + data);
});

openssl.on('exit', function (code) {
  console.log('child process exited with code ' + code);
});