Init, short for "initialization," is the first process the Linux kernel starts after booting. It is responsible for bringing the system to a usable state by starting system processes, running startup scripts, and managing runlevels. SysvInit, Systemd, and OpenRC are the different and most used init...

dmesg command displays messages retrieved from the kernel ring buffer during boot. It contains a lot of useful informations about hardware, kernel modules and device drivers. In case of hardware failure, the dmesg gives all required informations. It is frequently combined with commands such as grep,...

This bash tip can be useful when you frequently use two commands back-to-back. Most used commands are probably cd & ls and cp /mv and cd.

1. cd and ls in one command

Open .bashrc :

nano ~/.bashrc

Add the following function at the end:

cds() {
        cd "$@" && ls;
}

After modifying .bas...

The dig command, short for "domain information groper," is used for querying DNS (Domain Name System) name servers. It can perform :

• DNS lookups and displays the answers returned from the queried name server(s).
• Query Specific Record Types such as MX (Mail Exchanger) records for email servers...

1. User & Login Information

1.1 who

Shows users currently logged in.

who
sc       tty1         2025-11-05 08:11

1.2 w

Displays who is logged in and their activity.

w

09:34:20 up  1:23,  1 user,  load average: 1,97, 2,00, 1,93
USER     TTY      FROM             LOGIN@   IDLE   JCPU   PCP...