Day 3 #90DaysOfDevOps

Day 3 #90DaysOfDevOps

Basic Linux Commands

1. To View What's Written in a File:

The cat command is used to display the contents of a file on the terminal. For example, to view the contents of a file named fruits.txt, run the following command:

cat fruits.txt

2.To Change the Access Permissions of Files:

The chmod command is used to change the access permissions of files. For example, to give the owner of a file read, write, and execute permissions and everyone else only read and execute permissions, run the following command:

chmod 755 filename

3.To Check Which Commands You Have Run Till Now:

The history command is used to show a list of all the commands you have run in the current terminal session. For example:

history

4.To Remove a Directory/Folder:

The rmdir command is used to remove an empty directory or folder. For example, to remove a directory named saurabh, run the following command:

rmdir saurabh

5.To Create a Fruits.txt File and to View the Content:

The touch command is used to create a new file. For example, to create a file named fruits.txt, run the following command

touch fruits.txt

You can use the cat command to view the contents of the newly created file:

cat fruits.txt

6.To Add Content in devops.txt (One in Each Line):

The echo command is used to add content to a file. For example, to add the words "Apple", "Mango", "Banana", "Cherry", "Kiwi", "Orange", and "Guava" to the file named devops.txt, one on each line, run the following commands:

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

7.To Show Only Top Three Fruits from the File:

The head command is used to display the first few lines of a file. For example, to show only the top three fruits from the devops.txt file, run the following command:

head -n 3 devops.txt

8.To Show Only the Bottom Three Fruits from the File:

The tail command is used to display the last few lines of a file. For example, to show only the bottom three fruits from the devops.txt file, run the following command:

tail -n 3 devops.txt

9.To Create Another File Colors.txt and to View the Content:

You can create another file named Colors.txt using the touch command:

touch Colors.txt

To view the contents of the newly created file, use the cat command:

cat Colors.txt

To Add Content in Colors.txt (One in Each Line)

Use the echo command to add the words "Red", "Pink", "White", "Black", "