posix_spawn_file_actions_adddup2
int posix_spawn_file_actions_adddup2(posix_spawn_file_actions_t *, int, int);
error = posix_spawn_file_actions_adddup2(&fileacts, fd, STDOUT_FILENO);
error = posix_spawn_file_actions_adddup2(&fileacts, fd, STDOUT_FILENO);
error = posix_spawn_file_actions_adddup2(&fileacts, fd, STDOUT_FILENO);
error = posix_spawn_file_actions_adddup2(&fileacts, fd, STDOUT_FILENO);
error = posix_spawn_file_actions_adddup2(&fileacts, fd, STDOUT_FILENO);
RZ(posix_spawn_file_actions_adddup2(&fa, 1, 7));
RZ(posix_spawn_file_actions_adddup2(&fa, fd[0], STDIN_FILENO));