linux cli

List open files

lsof -i
lsof -i :3306
lsof # All open files in linux. Many lines come out.

i means internet(IPv4 and IPv6).

Netstat

List active internet connections, port

netstat -anpt

Process

See if the process is up

ps -ef | grep mariadb

Service (daemon) control

Assume sudo

systemctl start mariadb
systemctl stop mariadb
systemctl restart mariadb

systemctl enable mariadb
systemctl disable mariadb

systemctl status mariadb

service mariadb stop # systemctl is recommended way.

Listing

systemctl list-unit-files --type service -all # All services
systemctl list-units
systemctl list-units --state=failed

systemctl | grep running # All services running

service --status-all # All services

Where are the init services registered?

ll /etc/systemd/system

Link

ln -s /Users/chungchung/my/ZB/ZB-Assignments/month6/training-diary-backend ./training-diary-backend

This is a soft link. A hard link can't link to a directory.

System information

uname --all
uname -r # kernel version
uname -m

lspci # List pci to see connected hardwares. This is in pciutils package.

fdisk -l # See connected disks.

cat /etc/os-release # See OS information.