| Command | Description | Example |
|---|---|---|
pwd |
Print working directory | pwd |
ls |
List directory contents | ls |
cd [directory] |
Change directory | cd /home/user/Documents |
cp [source] [destination] |
Copy files or directories | cp file.txt /home/user/ |
mv [source] [destination] |
Move or rename files or directories | mv oldname.txt newname.txt |
rm [file] |
Remove files | rm file.txt |
touch [file] |
Create a new empty file | touch newfile.txt |
mkdir [directory] |
Create new directory | mkdir newdirectory |
rmdir [directory] |
Remove empty directory | rmdir olddirectory |
| Command | Description | Example |
|---|---|---|
cat [file] |
Concatenate and display file content | cat file.txt |
less [file] |
View file content page by page | less file.txt |
more [file] |
View file content with scrolling | more file.txt |
head [file] |
View the first 10 lines of a file | head file.txt |
tail [file] |
View the last 10 lines of a file | tail file.txt |
nano [file] |
Edit files with Nano editor | nano file.txt |
vi [file] |
Edit files with Vi editor | vi file.txt |
| Command | Description | Example |
|---|---|---|
chmod [mode] [file] |
Change file permissions | chmod 755 script.sh |
chown [owner][:group] [file] |
Change file owner and group | chown user:group file.txt |
| Command | Description | Example |
|---|---|---|
find [directory] -name [filename] |
Find files by name | find /home -name "*.txt" |
grep [pattern] [file] |
Search for a pattern within files | grep "search term" file.txt |
locate [name] |
Find files by name using a database | locate file.txt |
which [command] |
Show the path of a command | which python |
| Command | Description | Example |
|---|---|---|
uname -a |
Show all system information | uname -a |
df -h |
Show disk usage in human-readable format | df -h |
du -sh [directory] |
Show directory size | du -sh /home/user/ |
top |
Display real-time system processes | top |
free -h |
Show free and used memory | free -h |
uptime |
Show how long the system has been running | uptime |
who |
Show who is logged on | who |
dmesg |
Display kernel message buffer | dmesg |
| Command | Description | Example |
|---|---|---|
ip a |
Show IP addresses and network interfaces | ip a |
ping [host] |
Send ICMP ECHO_REQUEST to network hosts | ping google.com |
netstat -tuln |
Show listening ports | netstat -tuln |
ss -tuln |
Show listening ports (alternative to netstat) | ss -tuln |
curl [url] |
Transfer data from or to a server | curl http://example.com |
wget [url] |
Download files from the web | wget http://example.com/file.zip |
scp [source] [user@host:destination] |
Secure copy over SSH | scp file.txt user@remotehost:/home/user/ |
ssh [user@host] |
Connect to a remote host via SSH | ssh user@remotehost |
su - [user] |
Switch User e.g. su - root | su - root |
| Command | Description | Example |
|---|---|---|
apt update |
Update package lists (Debian/Ubuntu) | apt update |
apt upgrade |
Upgrade all packages (Debian/Ubuntu) | apt upgrade |
apt install [package] |
Install a package (Debian/Ubuntu) | apt install nginx |
yum update |
Update package lists (RHEL/CentOS) | yum update |
yum install [package] |
Install a package (RHEL/CentOS) | yum install httpd |
dnf update |
Update package lists (Fedora) | dnf update |
dnf install [package] |
Install a package (Fedora) | dnf install nginx |
| Command | Description | Example |
|---|---|---|
mount [device] [mountpoint] |
Mount a file system | mount /dev/sda1 /mnt |
umount [mountpoint] |
Unmount a file system | umount /mnt |
fdisk -l |
List disk partitions | fdisk -l |
mkfs.ext4 [device] |
Format a partition with ext4 | mkfs.ext4 /dev/sda1 |
fsck [device] |
Check and repair a file system | fsck /dev/sda1 |
| Command | Description | Example |
|---|---|---|
sh [script] |
Run a shell script | sh script.sh |
bash [script] |
Run a bash script | bash script.sh |
crontab -e |
Edit user crontab | crontab -e |
at [time] |
Schedule a job at a specific time | at 5pm |
| Command | Description | Example |
|---|---|---|
echo $VARIABLE |
Print value of a variable | echo $PATH |
export VARIABLE=value |
Set an environment variable | export PATH=/usr/local/bin:$PATH |
env |
List all environment variables | env |
| Command | Description | Example |
|---|---|---|
useradd [user] |
Add a new user | useradd newuser |
passwd [user] |
Change user password | passwd newuser |
userdel [user] |
Delete a user | userdel olduser |
groupadd [group] |
Add a new group | groupadd newgroup |
usermod -aG [group] [user] |
Add user to group | usermod -aG sudo newuser |
| Command | Description | Example |
|---|---|---|
tar -cvf [archive.tar] [directory] |
Create a tar archive | tar -cvf archive.tar /home/user/ |
tar -xvf [archive.tar] |
Extract a tar archive | tar -xvf archive.tar |
gzip [file] |
Compress a file with gzip | gzip file.txt |
gunzip [file.gz] |
Decompress a gzip file | gunzip file.txt.gz |
zip [archive.zip] [file] |
Create a zip archive | zip archive.zip file.txt |
unzip [archive.zip] |
Extract a zip archive | unzip archive.zip |
| Command | Description | Example |
|---|---|---|
alias [alias_name]='[command]' |
Create a command alias | alias ll='ls -la' |
history |
Show command history | history |
!! |
Run the last command again | !! |
man [command] |
Show the manual for a command | man ls |
echo [text] |
Print text to the terminal | echo "Hello, World!" |
date |
Show current date and time | date |
cal |
Show calendar | cal |