Top 60 Linux Commands Cheat Sheet.

Essential commands for daily use.

A. File and Directory Management Commands

ssh: Secure Shell, used for secure remote access to a system.
ls: List directory contents.
pwd: Print the current working directory.
cd: Change directory to a different folder.
touch: Create an empty file or update the modified timestamp of an existing file.
echo: Print a message or the value of a variable.
nano: A simple text editor.
vim: A more advanced text editor with many features.
cat: Print the contents of a file to the console.
shred: Securely delete a file by overwriting its contents.
mkdir: Create a new directory.
cp: Copy a file from one location to another.
mv: Move a file from one location to another, or rename a file.
rm: Remove a file.
rmdir: Remove a directory if it is empty.
ln: Create a link to a file or directory.
head: Display the first lines of a file.
tail: Display the last lines of a file.
cmp: Compare two files byte by byte.
diff: Display the differences between two files.
sort: Sort the lines of a file.
find: Search for files in a directory hierarchy.
chmod: Change the permissions of a file or directory.
chown: Change the owner of a file or directory.

B. System Management Commands

clear: Clear the console.
useradd: Add a new user to the system.
sudo: Run a command with administrative privileges.
adduser: Add a new user to the system with more options than useradd.
su: Switch to another user account.
exit: Close the current terminal or log out of the current user account.
sudo passwd: Change the password for the current user.
sudo passwd [username]: Change the password for another user.
sudo apt: A package manager used to install, update, and remove software packages on Debian-based systems.
sudo apt update & install: Update package lists and install packages.
finger: Display information about a user.
man: Display the manual page of a command.
whatis: Display a brief description of a command.
which: Locate a command and display its path.
whereis: Locate the binary, source, and manual page files for a command.
wget: Download files from the web.
curl: Transfer data to or from a server.
zip: Compress files into a zip archive.
unzip: Extract files from a zip archive.
less: View a file one page at a time.

C. File Comparison & Manipulation Commands

ifconfig: Configure network interfaces.
ip address: Display IP address information.
ping: Test network connectivity by sending packets to a host.
resolvectl status: Display the current DNS resolver configuration.
netstat: Display network connections, routing tables, and interface statistics.
iptables: Configure and administer the netfilter firewall.
ufw: A user-friendly interface to manage iptables firewall rules.

D. Networking Management & Monitoring Commands

uname: Print system information, including kernel name, network node hostname, kernel release, and kernel version.
neofetch: Display system information in a colorful and visually appealing way.
cal: Display a calendar of the current month or year.
free: Display the amount of free and used system memory.
df and df -h: Display disk usage statistics for a file system.
ps: Report a snapshot of current processes.
top: Display dynamic real-time information about running processes.
kill: Send a signal to terminate a process.
pkill: Send a signal to terminate one or more processes based on their name.
systemctl: Control the system and service manager.
history: Display previously executed commands.
sudo reboot: Reboot the system with administrative privileges.
shutdown: Shutdown or reboot the system.

credits: [NetworkChuck]

Linux Commands Cheat Sheet with Examples :

1. File and Directory Management

ls
List files and directories.
Example:
```
ls
```
ls -l
List files with detailed information.
Example:
```
ls -l
```
mkdir
Create a new directory.
Example:
```
mkdir new_folder
```
rmdir
Remove an empty directory.
Example:
```
rmdir empty_folder
```
rm
Delete files or directories.
Example:
```
rm file.txt
```
cp
Copy files or directories.
Example:
```
cp source.txt destination.txt
```
mv
Move or rename files.
Example:
```
mv old_name.txt new_name.txt
```
pwd
Show the current directory.
Example:
```
pwd
```

cat
Display file contents.
Example:
```
cat file.txt
```
less
View file with pagination.
Example:
```
less file.txt
```
head
Display the first 10 lines of a file.
Example:
```
head file.txt
```
tail
Display the last 10 lines of a file.
Example:
```
tail file.txt
```
tail -f
Follow updates to a file (e.g., log file).
Example:
```
tail -f log.txt
```

grep
Search for a pattern in a file.
Example:
```
grep "search_term" file.txt
```
grep -r
Search recursively in directories.
Example:
```
grep -r "search_term" directory/
```
find
Locate files by name or criteria.
Example:
```
find /path -name "file.txt"
```
locate
Search files quickly using a pre-built database.
Example:
```
locate file.txt
```
updatedb
Update the database for locate.
Example:
```
sudo updatedb
```

df -h
Show free disk space in human-readable format.
Example:
```
df -h
```
du -h
Show disk usage of files/directories.
Example:
```
du -h directory/
```

ip addr
Display network interfaces and IP addresses.
Example:
```
ip addr
```
ping
Test connectivity to a host.
Example:
```
ping google.com
```
netstat
View network connections.
Example:
```
netstat -tuln
```
nslookup
Query DNS records for a domain.
Example:
```
nslookup example.com
```
traceroute
Trace the route to a host.
Example:
```
traceroute google.com
```

apt update
Update package lists.
Example:
```
sudo apt update
```
apt upgrade
Upgrade installed packages.
Example:
```
sudo apt upgrade
```
apt install
Install a package.
Example:
```
sudo apt install curl
```
apt remove
Remove a package.
Example:
```
sudo apt remove package_name
```
apt search
Search for a package.
Example:
```
apt search package_name
```

uname -a
Display system information.
Example:
```
uname -a
```
free -h
Show memory usage in human-readable format.
Example:
```
free -h
```
uptime
Show system uptime.
Example:
```
uptime
```