Linux is a powerful and flexible operating system that provides users with a robust command-line interface (CLI) to interact with the system. The command-line offers greater control, efficiency, and the ability to automate tasks. Mastering Linux commands can make you more productive and empower you to troubleshoot, manage, and configure systems. Here’s a guide to 40 of the most popular Linux commands, useful for both beginners and experienced users.
1. ls – List Directory Contents
The ls command lists the contents of a directory. By default, it shows files and subdirectories of the current directory.
- Usage:
ls - Options:
ls -l: Long listing format (permissions, size, owner)ls -a: Show hidden filesls -h: Human-readable sizes
2. cd – Change Directory
The cd command changes the current working directory.
- Usage:
cd /path/to/directory - Shortcuts:
cd ~: Navigate to home directorycd ..: Move up one level in directory structure
3. pwd – Print Working Directory
This command prints the full path of the current directory.
- Usage:
pwd
4. cp – Copy Files and Directories
The cp command copies files or directories from one location to another.
- Usage:
cp source destination - Options:
cp -r: Copy directories recursivelycp -i: Prompt before overwriting
5. mv – Move or Rename Files
The mv command is used to move or rename files and directories.
- Usage:
mv source destination
6. rm – Remove Files and Directories
The rm command deletes files or directories.
- Usage:
rm file - Options:
rm -r: Remove directories and their contents recursivelyrm -f: Force removal without prompting
7. touch – Create Empty Files
The touch command creates an empty file or updates the timestamp of an existing file.
- Usage:
touch filename
8. cat – Concatenate and Display File Content
The cat command displays the contents of a file on the terminal.
- Usage:
cat filename - Option:
cat -n: Number the lines
9. mkdir – Make Directories
The mkdir command creates a new directory.
- Usage:
mkdir directory_name - Option:
mkdir -p /path/to/dir: Create parent directories if needed
10. rmdir – Remove Empty Directories
The rmdir command removes empty directories.
- Usage:
rmdir directory_name
11. echo – Display a Line of Text
The echo command prints a line of text to the terminal.
- Usage:
echo "Hello World"
12. df – Disk Space Usage
The df command shows disk space usage of file systems.
- Usage:
df - Option:
df -h: Human-readable format
13. du – Directory Disk Usage
The du command estimates the file space usage of a directory.
- Usage:
du directory_name - Option:
du -h: Human-readable formatdu -sh: Summary for a directory
14. find – Search for Files
The find command searches for files in a directory hierarchy.
- Usage:
find /path -name filename - Option:
find / -type d: Search for directories
15. grep – Search Inside Files
The grep command searches for patterns within files.
- Usage:
grep "pattern" file - Option:
grep -i: Case-insensitive search
16. chmod – Change File Permissions
The chmod command changes the permissions of files or directories.
- Usage:
chmod 755 file - Common permissions:
755: Owner has full control, group and others can read/execute644: Owner can read/write, others can only read
17. chown – Change File Ownership
The chown command changes the ownership of a file or directory.
- Usage:
chown user:group file
18. ps – Process Status
The ps command displays information about running processes.
- Usage:
ps - Option:
ps aux: Detailed process view
19. kill – Terminate Processes
The kill command terminates a process by its PID (Process ID).
- Usage:
kill PID - Option:
kill -9 PID: Forcefully terminate a process
20. top – Real-Time Process Monitoring
The top command provides a real-time view of running processes and system resource usage.
- Usage:
top
21. tar – Archive Files
The tar command is used to compress or extract files from an archive.
- Usage:
- To create an archive:
tar -cvf archive.tar file - To extract:
tar -xvf archive.tar
- To create an archive:
22. zip – Compress Files
The zip command compresses files into a .zip archive.
- Usage:
zip archive.zip file
23. unzip – Extract Zip Archives
The unzip command extracts files from a .zip archive.
- Usage:
unzip archive.zip
24. wget – Download Files from the Web
The wget command downloads files from the web using HTTP, HTTPS, or FTP protocols.
- Usage:
wget http://example.com/file
25. curl – Transfer Data from a URL
The curl command retrieves content from a URL, supporting various protocols.
- Usage:
curl http://example.com
26. apt – Package Management (Debian-based)
The apt command manages software packages in Debian-based distributions (like Ubuntu).
- Usage:
- To install:
apt install package - To update:
apt update - To upgrade:
apt upgrade
- To install:
27. yum – Package Management (RedHat-based)
The yum command manages software packages on RedHat-based distributions like CentOS.
- Usage:
- To install:
yum install package - To update:
yum update
- To install:
28. df – Disk Usage Overview
This command shows the disk usage on mounted filesystems.
- Usage:
df -h(human-readable format)
29. nano – Text Editor
The nano command opens a basic text editor in the terminal.
- Usage:
nano filename
30. vim – Advanced Text Editor
The vim command opens a more advanced, but highly efficient text editor.
- Usage:
vim filename
31. history – Show Command History
The history command displays the list of previously executed commands.
- Usage:
history
32. alias – Create Shortcuts for Commands
The alias command creates shortcuts for longer commands.
- Usage:
alias shortname='command' - Example:
alias ll='ls -la'
33. ping – Test Network Connectivity
The ping command checks the network connection to a host.
- Usage:
ping google.com
34. netstat – Network Statistics
The netstat command shows network connections, routing tables, and interface statistics.
- Usage:
netstat -tuln
35. ss – View Network Sockets
The ss command is a faster and more efficient alternative to netstat.
- Usage:
ss -tuln
36. uptime – System Uptime and Load
The uptime command shows how long the system has been running and the system load.
- Usage:
uptime
37. whoami – Display Current User
The whoami command shows the currently logged-in user.
- Usage:
whoami
38. hostname – Display System’s Hostname
The hostname command displays or sets the system’s hostname.
- Usage:
hostname
39. man – Manual Pages
The man command shows the manual (help) pages for any Linux command.
- Usage:
man command - Example:
man ls
40. reboot and shutdown – Restart or Power Off the System
- To reboot:
reboot - To shut down:
shutdown now
Conclusion
These 40 Linux commands are some of the most commonly used and fundamental to managing a Linux system. Whether you are navigating the file system, managing processes, networking, or configuring your system, mastering these commands will significantly enhance your productivity and system management skills.