Function child_is_sending_output

run-command.c:1513–1520

	return child_is_working(pp_child) && pp_child->process.in > 0;
}
static int child_is_sending_output(const struct parallel_child *pp_child)
{
	/*
	 * all pp children which buffer output through run_command via ungroup=0
	 * redirect stdout to stderr, so we just need to check process.err.
	 */
	return child_is_working(pp_child) && pp_child->process.err > 0;
}

struct parallel_processes {
	size_t nr_processes;