Operation
- To view the processes that is running,
top
OR
htop
You have to install htop with the following command
sudo apt install htop
- To view memory usage
free -h
where "h" is human readable numbers.
- To find the location of a program
whereis 7z
- To search text in a text file, replace the text that you are looking for in "some-search-text".
sudo cat /var/log/auth.log | grep some-search-text
If a file has been gzip (file extension is .gz), then, use zcat to
sudo zcat /var/log/auth.log.1.gz | grep some-search-text
Matching text1 and excluding text2, in this case, you need two grep commands. The first one is matching text1 and after that excluding text2.
sudo zcat /var/log/auth.log.1.gz | grep text1 | grep -Ev text2
- Find out current directory
pwd
- To search file in sub-directory:
find . -name myFileName*
- To cancel a command, CONTROL+C.
- To view current server name
hostname
- To change the host name
sudo hostnamectl set-hostname myserver01
Before rebooting the server,
sudo nano /etc/cloud/cloud.cfg
Then, change the following line from "false" to "true".
preseve_hostname: true
Save it and reboot the server.
- Viewing the server OS version
cat /etc/lsb-release
- To check if the server requires rebooting after apt update
cat /var/run/reboot-required
Daemon/service management
- To start, stop, restart or check status of a daemon
sudo systemctl [start|stop|restart|status] service_name
For example, check the fail2ban service
sudo systemctl status fail2ban
OR equivalent command:
sudo service fail2ban status
- To view all services
sudo systemctl -l
OR
sudo service --status-all
- To view failed services
sudo systemctl --failed
- Search for 'nginx' service
sudo service --status-all | grep nginx
apt command
- To view installed packages
sudo apt list --installed
sudo apt list -i
- View the list of upgradable packages,
apt list --upgradeable
- To upgrade the installed components,
sudo apt update
sudo apt full-upgrade
# you must reboot before upgrade
sudo reboot
# cleanup the unused components - this will recover some spaces
sudo apt --purge autoremove
# finally, upgrade the OS
sudo do-release-upgrade
sudo reboot
# cleanup the unused components - this will recover some spaces
sudo apt --purge autoremove
# finally, upgrade the OS
sudo do-release-upgrade
Personalize your console command by using "alias".
- Edit your console profile,
sudo nano ~/.bashrc
Then, add the following to the bottom of the file
alias f2b='sudo iptables -S | grep f2b'
alias f2b-log='sudo tail -n 30 /var/log/fail2ban.log'
alias auth-log='sudo tail /var/log/auth.log -n 100'
alias check-reboot='cat /var/run/reboot-required'
alias f2b-log='sudo tail -n 30 /var/log/fail2ban.log'
alias auth-log='sudo tail /var/log/auth.log -n 100'
alias check-reboot='cat /var/run/reboot-required'
Finally, saves the changes.
No comments:
Post a Comment