getStdout(); while ($chunk = yield $stream->read()) { echo $chunk; } $code = yield $process->join(); echo "Process {$process->getPid()} exited with {$code}\n"; } Amp\Loop::run(function () { $hosts = ['8.8.8.8', '8.8.4.4', 'google.com', 'stackoverflow.com', 'github.com']; $promises = []; foreach ($hosts as $host) { $process = new Process("ping {$host}"); $process->start(); $promises[] = new \Amp\Coroutine(show_process_output($process)); } yield all($promises); });