Command Cheat Sheet

Package Management (DNF)

Action	Command
Search for a package	dnf search <keyword>
Install a package	sudo dnf install <package>
Remove a package	sudo dnf remove <package>
Update all packages	sudo dnf update
List installed packages	dnf list installed
View package info	dnf info <package>
Find which package owns a file	dnf provides <file-path>
List repositories	dnf repolist
Clear cache	sudo dnf clean all
View update history	dnf history

Service Management (systemctl)

Action	Command
Start a service	sudo systemctl start <service>
Stop a service	sudo systemctl stop <service>
Restart a service	sudo systemctl restart <service>
Reload configuration	sudo systemctl reload <service>
View status	systemctl status <service>
Enable at boot	sudo systemctl enable <service>
Disable at boot	sudo systemctl disable <service>
Start and enable at boot	sudo systemctl enable --now <service>
List running services	systemctl list-units --type=service --state=running

Firewall (firewalld)

Action	Command
Check status	sudo firewall-cmd --state
View all rules	sudo firewall-cmd --list-all
Allow a service	sudo firewall-cmd --add-service=http --permanent
Allow a port	sudo firewall-cmd --add-port=8080/tcp --permanent
Reload rules	sudo firewall-cmd --reload
List allowed services	sudo firewall-cmd --list-services

SELinux

Action	Command
Check mode	getenforce
Temporarily set Permissive	sudo setenforce 0
Temporarily set Enforcing	sudo setenforce 1
View file context	ls -Z <path>
Restore default context	sudo restorecon -Rv <path>
View booleans	getsebool -a | grep <keyword>
Set a boolean	sudo setsebool -P <boolean> on
View denial logs	sudo ausearch -m avc -ts recent

Networking

Action	Command
View IP addresses	ip addr show
View routing table	ip route show
View network connections	nmcli connection show
View listening ports	ss -tlnp
DNS lookup	dig <domain> or nslookup <domain>
Test connectivity	ping -c 3 <address>
Trace route	traceroute <address>

User Management

Action	Command
Add a user	sudo useradd <username>
Set a password	sudo passwd <username>
Delete a user	sudo userdel -r <username>
Add to a group	sudo usermod -aG <group> <username>
View user info	id <username>
Switch user	su - <username>

Logs

Action	Command
View system logs	journalctl
Current boot logs	journalctl -b
Follow in real time	journalctl -f
Specific service logs	journalctl -u <service>
Error level and above	journalctl -p err
Specific time range	journalctl --since "1 hour ago"

Disk & Storage

Action	Command
View disk usage	df -h
View directory size	du -sh <path>
List block devices	lsblk
View LVM	lvs / vgs / pvs

System Information

Action	Command
System version	cat /etc/redhat-release
Kernel version	uname -r
Hostname	hostnamectl
Uptime	uptime
Memory usage	free -h
CPU info	lscpu