Users

Get root user

su root OR sudo -s

Get current debian version

less /etc/debian_version

Show users: less /etc/passwd

kacperbak:x:1000:1000:Kacper Bak,,,:/home/kacperbak:/bin/bash

Show users: less /etc/group

sudo:x:27:kacperbak
kacperbak:x:1000:

Network

Show open ports

sudo netstat -tulpn

Show firewall status

sudo ufw status

Services

Systemd

debug systemd on the fly

journalctl -f

Start a service

systemctl start app.service

Stop a service

systemctl stop app.service

Is-failed service

systemctl is-failed app.service

Reset all failed services

systemctl reset-failed

Show all services/units and their state.

systemctl list-units -t service --all | grep -w "active"

System

Get basic system information
lsb_release -a
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