systemctl —— 方括号表示可以省略的部分。

systemctl

进程与系统

用法

systemctl <verb> <unit>

启动、停止和查看 systemd 服务；`enable` 只决定开机行为，想现在也启动要用 `enable --now`，改过 unit 文件后必须 `daemon-reload`。

常用选项

选项	含义
status <unit>	Whether it is running, its PID, and the last log lines.
start / stop / restart	Act on the service now, without changing boot behaviour.
reload	Re-read the config without dropping connections, if the service supports it.
enable --now <unit>	Start it now and also start it at every boot.
daemon-reload	Required after you edit a .service file, before restarting it.
list-units --failed	Everything that failed to start.
--user	Act on your own user units instead of the system ones.

示例

sudo systemctl restart nginx

Restart the web server.

systemctl status sshd --no-pager

Print the state and recent log lines without opening a pager.

sudo systemctl enable --now docker

Start Docker and make it come back after a reboot.

看什么在跑、什么在吃机器。先弄清是什么，再决定杀不杀。

怎么看

Q. systemctl 是做什么的？

启动、停止和查看 systemd 服务；`enable` 只决定开机行为，想现在也启动要用 `enable --now`，改过 unit 文件后必须 `daemon-reload`。

Q. 怎么写？

systemctl <verb> <unit> —— 方括号表示可以省略的部分。

Q. 值得记的选项有几个？

这里列了 7 个，完整列表在 man systemctl。这条命令属于进程与系统。