'wait on spawned procs to start'

def wait(self, **kwargs):

    status = 0
    for proc in self.procs:
        output = proc.stdout.read()
        if kwargs.get('once', False):
            proc.wait()
        if output:
            print(output)
            start = time.time()
            while ((time.time() - start) < WARNING_WAIT):
                time.sleep(0.1)
                if (proc.poll() is not None):
                    status += proc.returncode
                    break
    return status
