A Selection of Important Linux Commands
CURIAWEB GmbH — Knowledgebase
Linux and Unix offer a wide range of commands that allow you to control your system directly via the terminal. Below is a compact overview of the most common commands, suitable for most Linux distributions (e.g., Ubuntu, Debian, CentOS, Fedora).
Tip: In many distributions, you can open the terminal with Ctrl + Alt + T. Alternatively, search for "Terminal" in the application menu.
File and Directory Commands
| Command |
Description |
ls |
Display the contents of a directory |
cd |
Change to another directory |
cp |
Copy a file or directory |
mv |
Move or rename a file |
chmod |
Change permissions of a file/directory |
chown |
Change owner and group of a file/directory |
dd |
Copy data block by block, clone, create images |
diff |
Compare the contents of two files line by line |
df |
Show free space of all mounted drives |
du |
Show disk usage of a directory |
grep |
Search for text patterns in files or output |
lsof |
List open files |
mount |
Mount a filesystem |
pwd |
Show the current working directory |
umount |
Unmount a filesystem |
mkdir |
Create a new directory |
rm |
Delete files or directories |
rmdir |
Delete an empty directory |
rsync |
Synchronize or transfer data |
ftp |
Start an FTP session |
sftp |
Start an SFTP session |
scp |
Securely transfer files |
shred |
Securely delete files |
Finding Files
| Command |
Description |
find |
Search for files by date, size, name, or pattern |
grep |
Search text in files or output |
locate |
Quick search using the `locatedb` database |
whereis |
Search for programs in standard directories |
which |
Show the path to a program in the `PATH` |
Compressing and Extracting Files
| Command |
Description |
bunzip2 |
Extract `.bz2` files |
bzip2 |
Compress files to `.bz2` format |
compress |
Compress files (older tools) |
gunzip |
Extract `.gz` files |
gzip |
Compress files to `.gz` format |
tar |
Create or extract tar archives (tar -czf, tar -xzf) |
uncompress |
Decompress files |
unzip |
Extract `.zip` archives |
zip |
Compress files to `.zip` format |
System Commands
| Command |
Description |
free |
Display memory usage |
uptime |
Show system uptime |
date |
Display date and time |
ps |
Show active processes |
pstree |
Display processes in a tree structure |
uname |
Show system information |
top |
Show running processes in real time |
kill |
Terminate a process (e.g., kill -9 PID) |
killall |
Terminate all processes with a given name |
clear |
Clear the terminal |
man |
Show the manual page for a command |
reboot |
Restart the system |
shutdown |
Shut down the system |
wall |
Send a message to all logged-in users |
User and Group Management
| Command |
Description |
chfn |
Change user information |
id |
Show user and group IDs |
last |
Show last logins |
login |
Log in as a user |
who |
Show currently logged-in users |
whoami |
Display the current username |
passwd |
Change a user's password |
su |
Switch to another user (e.g., root) |
sudo |
Run a command with administrative privileges |
useradd |
Create a new user |
userdel |
Delete a user |
usermod |
Modify a user |
groupadd |
Create a new group |
groupdel |
Delete a group |
groupmod |
Modify a group |
Network Commands
| Command |
Description |
ping |
Test connectivity to an IP/domain |
traceroute |
Show the data path to a target server |
netstat |
Show currently used ports and connections |
nslookup |
Perform a DNS query |
dig |
Advanced DNS lookup |
ifconfig |
Display/configure network interfaces (on modern systems often replaced by ip) |
Hardware Commands
| Command |
Description |
lscpu |
Display CPU information |
lshw |
Display detailed hardware information (requires root) |
lspci |
List PCI devices |
lsusb |
List USB devices |
Other Useful Commands
| Command |
Description |
head |
Display the first lines of a file |
tail |
Display the last lines of a file (e.g., tail -f for live logs) |
less |
View a text file page by page |
xargs |
Convert input into command arguments |
wget |
Download files from the web (HTTP/HTTPS/FTP) |
curl |
Transfer data to/from a server |
ssh |
Establish a secure connection to a remote computer |
cal |
Display a simple calendar |
Conclusion: These commands cover many of the daily tasks in Linux — from file management and system diagnostics to network and user management.
If you have any questions, our CURIAWEB Support will be happy to help you.
