Skip to content

Linux

Commands

List all envirlonment variables

printenv

Editing the crontab

crontab -e

Editing the systemd service

vim /etc/systemd/system/xxx.service

To check all the systemd services on a Linux system

systemctl list-units --type=service

Checking the listening port

lsof -i tcp:8080

Change the hostname

  • Open the terminal and enter the following command to edit the hosts file:
vim /etc/hosts
  • In the hosts file, look for the line that contains the current hostname and edit it to the new hostname that you wish to use. Replace "old_hostname" with the current hostname and "new_hostname" with the new hostname you have chosen.
127.0.0.1 old_hostname

Change it to:

127.0.0.1 new_hostname
  • Now, enter the following command to edit the hostname file:
vim /etc/hostname

  • Replace the old hostname with the new hostname that you have chosen, and then save and close the file.

  • Reboot your system using the following command:

reboot

To find the specify process

ps -ef grep | xxx

To find the process by name

ps aux | grep xxx

find the Correct USB Device Name

lsblk

copy the ISO image to the USB flash drive

dd bs=1M conv=fdatasync if=./proxmox-ve_*.iso of=/dev/XYZ

SSH

Start the ssh-agent

eval "$(ssh-agent -s)"

To add ssh private key

ssh-add xxxx

To calculate the sha256 in macOS

shasum -a 256 filename

Network

to display the detailed output of the curl command

curl -v https://google.com

create a VLAN interface

ip link show

ip link add link eth0 name eth0.10 type vlan id 10

ip link set eth0.10 up

ip addr add 192.168.10.2/24 dev eth0.10 // optional

Disk

list the disk usage

df -h

list the large files

du -ah / | sort -rh | head -n 10
Back to top