Systemd提供了一个结构化的可配置方法来管理临时文件和目录，即systemd-tmpfiles，可以创建、删除和管理临时文件的服务。
$ systemctl list-units --all | grep systemd-tmpfiles
systemd-tmpfiles-clean.service loaded inactive dead Cleanup of Temporary Directories
systemd-tmpfiles-setup-dev.service loaded active exited Create Static Device Nodes in /dev
systemd-tmpfiles-setup.service loaded active exited Create Volatile Files and Directories
systemd-tmpfiles-clean.timer loaded active waiting Daily Cleanup of Temporary Directories
