Essential Red Hat Linux Commands for Beginners

Essential Red Hat Linux Commands

Red Hat Enterprise Linux (RHEL) is widely used in enterprise environments, offering robust performance, stability, and security. Here’s a quick reference guide to the most commonly used commands in RHEL:

1. System Information Commands

uname -r: Display the kernel version.
```
uname -r
```
hostnamectl: View or modify system hostname and basic system information.
```
hostnamectl
```
uptime: Show how long the system has been running.
```
uptime
```
whoami: Display the currently logged-in user.
```
whoami
```
id: Show user ID (UID) and group ID (GID).
```
id
```

2. File Management Commands

ls: List files and directories.
```
ls -l
```
pwd: Print the current working directory.
```
pwd
```
cp: Copy files or directories.
```
cp source_file target_directory
```
mv: Move or rename files.
```
mv old_name new_name
```
rm: Remove files or directories.
```
rm file_name
```
mkdir: Create directories.
```
mkdir directory_name
```

3. User Management Commands

who: Display logged-in users.
```
who
```
adduser: Add a new user.
```
sudo adduser username
```
passwd: Change a user's password.
```
passwd username
```
usermod: Modify user accounts.
```
sudo usermod -aG groupname username
```
deluser: Delete a user.
```
sudo deluser username
```

4. Process Management Commands

ps: Display currently running processes.
```
ps -aux
```
top: Monitor system processes in real time.
```
top
```
kill: Terminate a process by PID.
```
kill PID
```
htop: Interactive process manager (requires installation).
```
htop
```

5. Package Management Commands (YUM/DNF)

dnf update: Update all packages.
```
sudo dnf update
```
dnf install: Install a package.
```
sudo dnf install package_name
```
dnf remove: Remove a package.
```
sudo dnf remove package_name
```
dnf search: Search for a package.
```
dnf search package_name
```

6. Networking Commands

ip a: Display network interfaces and IP addresses.
```
ip a
```
ping: Test network connectivity.
```
ping example.com
```
curl: Transfer data from or to a server.
```
curl http://example.com
```
wget: Download files from the web.
```
wget http://example.com/file
```

7. Disk Management Commands

df -h: Display disk usage in human-readable format.
```
df -h
```
du -sh: Show the size of a directory.
```
du -sh /path/to/directory
```
mount: Mount a filesystem.
```
sudo mount /dev/sdX /mnt
```
umount: Unmount a filesystem.
```
sudo umount /mnt
```
lsblk: List information about block devices.
```
lsblk
```

8. System Monitoring and Logs

journalctl: View system logs.
```
sudo journalctl
```
dmesg: Display kernel ring buffer messages.
```
dmesg
```
free -h: Show memory usage.
```
free -h
```

9. Permissions and Ownership Commands

chmod: Change file permissions.
```
chmod 755 file_name
```
chown: Change file ownership.
```
sudo chown user:group file_name
```

10. Shutdown and Reboot

shutdown: Shut down the system.
```
sudo shutdown now
```
reboot: Restart the system.
```
sudo reboot
```

Conclusion

These commands form the foundation for managing a Red Hat Enterprise Linux system. Whether you are an administrator or a curious learner, mastering these basics is essential for navigating the RHEL environment.

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Souy Soeng