Linux commands can seem daunting at first, but with practice and understanding, they become powerful tools for navigating and managing your system efficiently. In this guide, we will walk through some essential commands, from viewing files to managing directories and comparing contents.

Viewing File Contents

One of the fundamental tasks in Linux is viewing the contents of a file. The cat command is commonly used for this purpose:

cat filename.txt

This command will display the entire contents of the specified file on the terminal.

Changing File Permissions

Linux offers powerful permissions management for files and directories. The chmod command is used to change access permissions:

chmod permissions filename

For example, to give read, write, and execute permissions to the owner of the file:

chmod u+rwx filename

Viewing Command History

To check which commands you have run previously, you can use the history command:

history

This command will display a list of previously executed commands along with their line numbers.

Removing Directory/Folder

To remove a directory and all its contents, you can use the rm command with the -r option:

rm -r directory_name

Creating and Viewing File Content

To create a file, you can use the touch command. For example:

touch fruits.txt

To view the contents of the file:

cat fruits.txt

Adding Content to a File

You can add content to a file using redirection. For example, to add fruits to devops.txt:

echo "Apple" > devops.txt
echo "Mango" >> devops.txt
echo "Banana" >> devops.txt

Showing Top and Bottom Items

To show the top three fruits from the file:

head -n 3 fruits.txt

To show the bottom three fruits from the file:

tail -n 3 fruits.txt

Creating and Comparing Files

To create another file Colors.txt and view its content:

touch Colors.txt
cat Colors.txt

To add content to Colors.txt:

echo "Red" > Colors.txt
echo "Pink" >> Colors.txt
echo "White" >> Colors.txt
echo "Black" >> Colors.txt
echo "Blue" >> Colors.txt
echo "Orange" >> Colors.txt
echo "Purple" >> Colors.txt
echo "Grey" >> Colors.txt

To find the difference between fruits.txt and Colors.txt:

diff fruits.txt Colors.txt

This will display the lines that are unique to each file, helping you understand the differences between them.

Conclusion

Mastering these basic Linux commands provides a solid foundation for efficient system navigation and management. With practice and exploration, you'll become more comfortable with the Linux command line, empowering you to accomplish a wide range of tasks with ease.