Basic Linux Commands: A Beginner's Guide

Learning Linux can be overwhelming for new users. In this guide, I’ll cover some basic Linux commands to get you started with common tasks such as viewing files, changing permissions, and manipulating text files.

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Viewing a File

To view the content of a file, you can use the following commands:

• cat <file_name>: Displays the entire content of a file.

• more <file_name> or less <file_name>: Allows you to navigate through a file one page at a time.

• head -n <number> <file_name>: Shows the first n lines of a file.

• tail -n <number> <file_name>: Shows the last n lines of a file.

For example, to view the content of a file named example.txt, you can use:

cat example.txt

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Changing File Permissions

In Linux, you can change the access permissions of files using the chmod command. Permissions are defined by three groups: the owner, the group, and others.

• chmod 644 <file_name>: Sets read-write permissions for the owner and read-only for others.

• chmod 755 <file_name>: Sets read-execute permissions for all, but only the owner can write.

To grant execute permissions to a script script.sh, you can use:

chmod +x script.sh

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Checking Command History

To check the list of commands you've executed in the current session, you can use the history command:

history

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Removing a Directory

To remove a directory or folder, you can use rmdir for empty directories and rm -r for non-empty ones:

• rmdir <directory_name>: Removes an empty directory.

• rm -r <directory_name>: Removes a directory and its contents.

For example, to remove a directory named old_folder, you can use:

rm -r old_folder

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Creating and Manipulating Text Files

To create a new file and add content, you can use the echo or touch command, followed by a redirection operator (>, >>).

• To create a file named fruits.txt and view its content, use:

touch fruits.txt
cat fruits.txt

• To add content to devops.txt, one item per line, use:

echo "Apple" > devops.txt
echo "Mango" >> devops.txt
echo "Banana" >> devops.txt
echo "Cherry" >> devops.txt
echo "Kiwi" >> devops.txt
echo "Orange" >> devops.txt
echo "Guava" >> devops.txt

• To show only the top three fruits from devops.txt, use:

head -n 3 devops.txt

• To show only the bottom three fruits from devops.txt, use:

tail -n 3 devops.txt

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Creating a Second Text File and Finding Differences

To create a new file named Colors.txt and add content, use:

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 differences between fruits.txt and Colors.txt, you can use the diff command:

diff fruits.txt Colors.txt

This command will display the differences between the two files, allowing you to see where they differ.

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Conclusion

These basic Linux commands can help you get started with essential tasks in a Linux environment. Whether you're creating files, manipulating text, changing permissions, or exploring command history, these commands are the building blocks for more advanced Linux usage. Keep experimenting with them to become more comfortable in a Linux terminal.

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I hope this helps!

Happy Learning✨