subprocess.py 文件源码

def _close_fds(self, fds_to_keep):
            start_fd = 3
            for fd in sorted(fds_to_keep):
                if fd >= start_fd:
                    os.closerange(start_fd, fd)
                    start_fd = fd + 1
            if start_fd <= MAXFD:
                os.closerange(start_fd, MAXFD)