# What is the running system and service manager? [TOC] ###### tags: `*nix` `cli` --- ## First Method 系統第一個啟動的 process。 ### SysV ```shell $ ps -p 1 PID TTY TIME CMD 1 ? 00:00:01 init ``` ### systemd ```shell $ ps -p 1 PID TTY TIME CMD 1 ? 00:00:03 systemd ``` ### upstart ```shell $ ps -p 1 PID TTY TIME CMD 1 ? 00:00:01 init ``` ## Second Method 系統第一個啟動的 process 的 symbolic link。 ### SysV ```shell $ sudo ls -l /proc/1/exe lrwxrwxrwx 1 root root 0 Jan 1 00:00 /proc/1/exe -> /sbin/init ``` 或 ```shell $ sudo stat /proc/1/exe | grep File File: /proc/1/exe -> /sbin/init ``` ### systemd ```shell $ sudo ls -l /proc/1/exe lrwxrwxrwx 1 root root 0 Jan 1 00:00 /proc/1/exe -> /usr/lib/systemd/systemd ``` 或 ```shell $ sudo stat /proc/1/exe | grep File File: /proc/1/exe -> /usr/lib/systemd/systemd ``` ### upstart ```shell $ sudo ls -l /proc/1/exe lrwxrwxrwx 1 root root 0 Jan 1 00:00 /proc/1/exe -> /sbin/upstart ``` 或 ```shell $ sudo stat /proc/1/exe | grep File File: /proc/1/exe -> /sbin/upstart ``` ## Third Method `/sbin/init` 的指向。 ### SysV ```shell $ sudo ls -l /sbin/init lrwxrwxrwx 1 root root 0 Jan 1 00:00 /sbin/init ``` ### systemd ```shell $ sudo ls -l /sbin/init lrwxrwxrwx 1 root root 0 Jan 1 00:00 /sbin/init -> /lib/systemd/systemd ``` ### upstart ```shell $ sudo ls -l /sbin/init lrwxrwxrwx 1 root root 0 Jan 1 00:00 /sbin/init -> upstart ``` ## Reference - [Detecting which system manager is running on Linux System](https://linuxconfig.org/detecting-which-system-manager-is-running-on-linux-system) ## See Also - [Spring Boot Application as a Service](https://www.baeldung.com/spring-boot-app-as-a-service)