In this article, we will see the different ways to add a header record or a trailer record to a file. Let us consider a file, file1. $ cat file1 apple orange grapes banana Adding a line to the start of the file (header) 1. To add a header record using sed: $ sed ‘1i […]
DevOps
How to Install awscli
What is the AWS CLI? The AWS Command Line Interface (CLI) is for managing your AWS services from a terminal session on your own client, allowing you to control and configure multiple AWS services and implement a level of automation. If you’ve been using AWS for some time and feel comfortable clicking your way through […]
Shell Script to print pyramid of Stars
The Basics So here we will print the pyramid of stars in two parts as shown below. We will loop through the number provided by the user and print the first half of the stars using a for loop and other half using another for loop. The spaces and new line characters are added in […]
Shell/Bash Script to Find Prime Numbers in Linux
A prime number is a whole number that has exactly 2 different factors, 1 and itself. A number that is not a prime number will be called composite. Except 1 each natural number that is divisible by only 1 and itself is called a prime number. For example: 2,3,5,7,11,13,17,19,23,29… etc. There are total 25 prime […]
How to convert text files to all upper or lower case
As usual, in Linux, there are more than 1 way to accomplish a task. To convert a file (input.txt) to all lower case (output.txt), choose any ONE of the following: To convert a file (input.txt) to all lower case (output.txt) 1. dd: You may have used dd for many other purposes but it can be […]
ValueError: Masked arrays must be 1-D
Scatter plot is a basic plot of dots. You can draw it by calling plt.scatter(x,y). The following example shows a scatter plot of random dots: import numpy as np import matplotlib.pyplot as plt # Set the random seed for NumPy function to keep the results reproducible np.random.seed(42) # Generate a 2 by 100 NumPy Array […]
EFS Mount Issue “Failed to resolve server: Name or service not known”
The Problem mount.nfs4: Failed to resolve server fs-d3d54350.efs.us-east-1.amazonaws.com: Name or service not known or: ping: unknown host fs-d3d54350.efs.us-east-1.amazonaws.com The Solution 1. Open the Amazon VPC console. 2. Select the VPC. 3. Review the information in the Description tab. In this example, both settings are enabled. DNS resolution Enabled DNS hostnames Enabled 4. To update these […]
How to Stop and Start Ec2 instance using Jenkins
Jenkins is an open-source Continuous Integration tool. However, it’s not limited to Continuous Integration alone. Jenkins is supported by a large number of plugins that enhance its capability. The Jenkins tool is written in Java and so are its plugins. The tool has a minimalistic GUI that can be improved using specific plugins if required. […]
How to Use External Python modules in MySQL Shell
MySQL Shell is a great tool for working with MySQL. One of the features that make it stand out compared to the traditional mysql command-line client is the support for JavaScript and Python in addition to SQL statements. This allows you to write code you otherwise would have had to write outside the client. This […]
The Ultimate Beginner’s Guide to Static Website Hosting With Google Firebase (for FREE)
I am a total noob when it comes to web development but I am improving my tech skills every day. I have tried to keep this post as simple as I can so that it could help beginners like me. I have taken care of all the steps and codes I mentioned in this blog […]