spawn-with-fd-used-twice.js

var spawn = require('child_process').spawn;
var open = require('fs').openSync;

console.log('process stdout', process.pid);
console.error('process stderr', process.pid);

if(process.env.i_am_child) {
  console.error('child is alive');
} else {
  var fd = open('out.txt', 'a');

  process.env.i_am_child = true;

  // Redirect stdout and stderr in child to the same file
  var child = spawn(process.argv[0], process.argv.slice(1), {
    stdio: ['ignore', fd, fd]
  });

  console.error('spawned child', child.pid);

  child.on('exit', function(code,signal) {
    console.error('child exit with', code, signal);
  });
}