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Scripting 101: The missed part of your Computer Science Education

vaibhavx42 — Sun, 23 Apr 2023 12:01:11 +0000

Shell We Begin?

Computers are pretty good at doing the same thing over and over again as computer scientists we know that. But sometimes we forget that we can also do things better with them. While we have access to numerous tools that can enhance our productivity, our proficiency is often limited to a handful of tricks. In the face of challenges, we resort to copy-pasting commands as a quick fix. However, it's essential to expand our skill set and delve deeper into the realm of scripting. With a better understanding of scripting, we can overcome obstacles and accomplish more than ever before.

This series is an attempt to change how you work

Throughout this series, we will be exploring six to seven distinct topics that span the entire spectrum of scripting. The blogs will cover everything from the fundamentals of scripting to advanced techniques such as data wrangling and MetaProgramming

Each blog in this series will include exercises and external resources to help you apply the concepts covered. While the command line might feel difficult and confusing at first, it's designed to simplify your life, not make it more complex. So, don't be afraid to dive in and experiment. Practice consistently and use the provided resources to develop your skills.

Shell, What is it?

If you read the first line of the blog carefully it says Shell we begin instead of Shall we begin? The shell here is nothing but a command-line interface that provides a way for users to interact with the operating system.

but

We already have GUI and everything programmed why bother with the command line and shell scripting?

Yes, that's true for most things in fact 80 percent of things but Graphical interfaces and voice commands are limited in what they can do, restricting users to a set of programmed actions. To fully utilize the capabilities of a computer, one must turn to the old-school textual interface: The Shell. While shells may differ in specifics, their core function remains the same: running programs, providing input, and inspecting output in a structured way. Shells exist on almost every platform, providing users with a powerful tool for computer interaction.

You can also think of the shell as a mediator between you and your operating system, allowing you to perform tasks that may not be possible through the graphical user interface. Think of it as a command-line interface to interact with the kernel of your operating system. Whether you're on Windows, Linux, or macOS, the shell provides a powerful toolset for interacting with your system and getting things done.

Interacting with Shell

Upon launching your terminal, it is common to encounter a prompt that may resemble the following.

vaibhav:~$

This prompt provides information about the machine you're using (such as the name "vaibhav") and displays your current working directory (often indicated by "~" to represent the home directory).
The "$" symbol indicates that you are currently logged in as a non-root user. From this prompt, you can enter commands for the shell to execute, such as running a program.

vaibhav:~$ whoami

If you execute the "whoami" command in the Bash shell and you are logged in as a user named "vaibhav", the output will be

vaibhav:~$ whoami
vaibhav

Let's try some more commands

vaibhav:~$  echo this
this

When we ran the command "echo this" in the shell, we instructed the shell to execute the "echo" program with the argument "this". The "echo" program simply prints out its arguments to the terminal. To execute a command, the shell parses the input by splitting it into individual words based on whitespace. The first word is assumed to be the name of the program to be run, and any subsequent words are treated as arguments to that program.

But how does he shell know how to find the this or echo programs? Well, the shell is a programming environment, just like Python or Ruby, and so it has variables, conditionals, loops, and functions (next lecture!). When you run commands in your shell, you are really writing a small bit of code that your shell interprets. If the shell is asked to execute a command that doesn’t match one of its programming keywords, it consults an environment variable called $PATH that lists which directories the shell should search for programs when it is given a command:

vaibhav:~$ echo $PATH
/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin

When we use the "echo" command in the shell, the shell looks for an executable program file with that name by searching through a list of directories specified in the $PATH environment variable. If it finds an executable file with the name "echo" in one of the directories listed in $PATH, it runs that file.

To determine which file the shell is executing for a particular command, we can use the "which" command. This will show us the path to the executable file that would be executed if we ran the command. Alternatively, we can bypass the search through $PATH and execute a specific file by providing the full path to that file.

Navigating the shell

A path in the shell is like a roadmap that shows you where your files and folders live. It's basically a list of directories separated by slashes on Linux and macOS or backslashes on Windows. On Linux and macOS, the path / is the big cheese of all directories - everything else is under it. But on Windows, each disk partition has its own top dog (like C:).

For the purposes of this class, we'll assume you're using a Linux file system. If a path starts with /, it's an absolute path. Any other path is relative to your current location. Speaking of location, you can use the "pwd" command to see where you are, and the "cd" command to change your current directory.

In a path, the dot "." refers to your current directory, kind of like how "you are here" on a mall map. And ".." refers to the directory one level up, like how you'd use the escalator to go up a floor.

vaibhav:~$ pwd
/home/vaibhav
vaibhav:~$ cd /home
vaibhav:/home$ pwd
/home
vaibhav:/home$ cd ..
vaibhav:/$ pwd
/
vaibhav:/$ cd ./home
vaibhav:/home$ pwd
/home
vaibhav:/home$ cd vaibhav
vaibhav:~$ pwd
/home/vaibhav
vaibhav:~$ ../../bin/echo hello
hello

In general, when we run a program, it will operate in the current directory unless we tell it otherwise. For example, it will usually search for files there, and create new files there if it needs to.

To see what lives in a given directory, we use the ls command:

vaibhav:~$ ls
vaibhav:~$ cd ..
vaibhav:/home$ ls
vaibhav
vaibhav:/home$ cd ..
vaibhav:/$ ls
bin
boot
dev
etc
home
...

Man Command the Saviour

MAN command is used to display the manual pages for other commands and topics. The manual pages, or "man pages" for short, provide detailed documentation and information about various commands, system calls, library functions, and other topics related to the Unix operating system.

When you type man followed by the name of a command or topic, the man command searches for and displays the corresponding manual page. For example, to view the manual page for the ls command, you would enter:

man ls

This would display the manual page for the ls command, which includes information about its usage, options, and examples.

Some commands for you to explore

mv - (to rename/move a file)
cp - (to copy a file)
mkdir - (to make a new directory)

Exercises

If you've reached this part of the blog know that I'm extremely proud of you trying to learn this topic You've been learning the hard thing, Keep up the great work and keep learning! Below are some exercises for you to try on your own you can always reach out to me if you're stuck anywhere

Install WSL from here. - If you are on Linux or macOS, you don’t have to do anything special. If you are on Windows, you need to make sure you are not running cmd.exe or PowerShell; you can use WSL to run UNIX like commands.
Look up the touch program. The man program is your friend.
Use the mkdir command to create a new directory called my_folder.
Use the cd command to navigate to my_folder.
Use the touch command to create two new files called file1.txt and file2.txt.
Use the ls command to verify that the two new files were created.
Use the echo command to write some text to file1.txt.

Whenever you do these tweet about them and tag me It's always better to learn in public .

Conclusion

In conclusion, understanding the shell and scripting is essential for any computer scientist, as it allows us to expand our skill set and accomplish more than ever before. The shell serves as a mediator between the user and the operating system, allowing us to perform tasks that may not be possible through the graphical user interface. By using the shell, we can interact with the kernel of our operating system and execute powerful commands.

Connect with Me

If you enjoyed this post and would like to stay updated on my work, feel free to connect with me on social media

Linkedin: Click here
Twitter: Click here

I'm always open to new connections and networking opportunities, so don't hesitate to reach out and say hello. Thank you for reading!

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Demystifying APIs

vaibhavx42 — Fri, 17 Mar 2023 06:59:31 +0000

What is an API?

APIs (Application Programming Interfaces) are a way for different software systems to communicate with each other. They allow the frontend (i.e. the part of the application that interacts with the user) to send requests to the backend (i.e. the part of the application that interacts with the database or other external services) and receive responses.

APIs are like the middlemen of the internet. They're the go-betweens that help different websites and apps talk to each other, kind of like that one friend you have who's really good at setting people up on dates.
Just like your matchmaking friend, APIs make sure that the right information gets sent to the right place, so everyone's happy and nobody gets ghosted.

APIs are like the oxygen of the internet. They're everywhere and you don't even realize it. They're the secret sauce that makes all your favorite apps and websites work together seamlessly.
APIs are a fundamental building block of the modern internet, and their presence can be found everywhere from web development to mobile apps, to cloud computing and beyond.
Their widespread use and integration allow for seamless communication and data exchange, and their importance in driving innovation in the software industry cannot be overstated.

Types of API

Public API - Also known as Open API available to developers and other users with minimal restrictions.
Partner API - A partner API, only available to specifically selected and authorized outside developers or API consumers, is a means to facilitate business-to-business activities.
Internal API - An internal or private API is only meant to be used inside the company to link together systems and data. For instance, an internal API may link the payroll and HR systems of a firm.
Composite API - A composite API majority of the time, integrates two or more APIs to create a chain of connected or interdependent activities.

Types of API Protocols

SOAP - Simple Objects Access Protocol
REST - Representational State Transfer
JSON-RPC - JavaScript Object Notation- Remote Procedural Call
gRPC - Google Remote Procedural Call
GraphQL - Graph QL
XML-RPC - Extensible Markup Language Remote Procedural Call
Apache Thrift - Implementation of RPC framework

We will be focussing on Rest and Soap Protocol in this blog.

What is Rest and Soap Protocol

Soap Protocol
1. SOAP (Simple Object Access Protocol) is an XML-based protocol for sending and receiving messages over the internet. It is typically used for building web services and is often used as an alternative to REST.
2. SOAP messages are typically sent over HTTP, but can also be sent over other transport protocols such as SMTP (Simple Mail Transfer Protocol). A SOAP message consists of an Envelope element, which contains a header and a body. The header contains metadata, such as authentication information, while the body contains the actual data being sent.
3. Messages in SOAP are encoded in XML specifically and have a properly defined format:
  - Envelope: Literally envelopes the entire message/data in tags.
  - Header: Defines all extra information that might be needed to process this data. This is an optional element.
  - Body: This is where we actually write the request for data required/ where all the requested data is added.
  - Fault: Defines all the errors that may arise in the data during/due to transmission and measures to handle them.
REST Protocol
1. REST protocols overcome SOAP's dependency on XML by including JSON (the most popular), HTML, Python, plain text, and media files, REST protocols get around SOAP's reliance on XML. However, REST eliminates SOAP's extensibility to other protocols by only using HTTP/HTTPS for data delivery. RESTful APIs are APIs that use the REST protocol.
2. Client-server architecture and statelessness are requirements for REST APIs. It is implied by stateless communication that no client data is kept in memory in between GET queries. All of these GET queries to need to be separate and unconnected. Every action in REST is given a distinct URL, allowing the server to know exactly what to do in response to a request by knowing which instructions to carry out. Caching is supported via REST. Thus, in order to increase speed and efficiency, the browser can locally store the results of the request and periodically retrieve them as needed.
3. A typical REST request has the following components:
  - Endpoint: The destination URL from which data is being requested.
  - Method: We use predefined methods such as GET, POST, PUT or DELETE to fetch the data. These methods vary from one another. Ex. when using GET, the data is appended to the end of the URL string, whereas in POST, the data is sent along with the HTTP request.
  - Headers: They define the request's details and dictate the proper format in which the response must be received.
  - Body: The actual data sent by the service.

What are the main types of HTTP vulnerability?

Cross-site scripting - Commonly known XSS is when an attacker injects HTML markup or JavaScript into the affected web application's front-end client.
SQL injection - SQL injection is a code injection technique that might destroy your database.
DDOS attacks - A distributed denial-of-service (DDoS) attack is a malicious attempt to disrupt the normal traffic of a targeted server, service or network by overwhelming traffic
Cross-site request forgery - Cross-Site Request Forgery (CSRF) is an attack that forces an end user to execute unwanted actions on a web application in which they’re currently authenticated

How to secure an API?

The first method of security is to use HTTPS on your site
The second method of security is to use Password hash you can apply some logic to hash the password
The third method of security is to add a password over every endpoint so that no one can access it
The fourth method of security is to add timestamps in API authentication adding timestamps to APIs can help you secure the API.

If you have reached this point and have honestly read every part of this blog.

Give Yourself a Pat on back and keep Learning about API.

Stay tuned for more such amazing blogs🚀🙌

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What is AWS ? – An Introduction to AWS

vaibhavx42 — Fri, 17 Mar 2023 06:59:25 +0000

What is AWS? With the advent of cloud computing, & AWS being the major shareholder, AWS certification is one the most sought-after skills in the industry. Hey there! Today in this “What is AWS” blog you will be learning about the following things:

What is AWS? – An Introduction How to build applications in AWS? Signing up on AWS Demo What is AWS in simple terms? – Introduction What is AWS? – Amazon Web Services(AWS) is a cloud service from Amazon, which provides services in the form of building blocks, these building blocks can be used to create and deploy any type of application in the cloud.

These services or building blocks are designed to work with each other, and result in applications that are sophisticated and highly scalable.

What are the services provided by AWS? Each type of service in this “What is AWS” blog, is categorized under a domain, the few domains which are widely used are:

Compute Storage Database Migration Network and Content Delivery Management Tools Security & Identity Compliance Messaging Compute Services The Compute domain includes services related to compute workloads, it includes the following services:

EC2 (Elastic Compute Cloud) Lambda Elastic Beanstalk Amazon LightSail Storage Services The Storage domain includes services related data storage, it includes the following services:

S3 (Simple Storage Service) Elastic Block Store Amazon Glacier AWS Snowball Database Services The Database domain is used for database related workloads, it includes the following services:

Amazon Aurora Amazon RDS Amazon DynamoDB Amazon RedShift Migration Services The Migration domain is used for transferring data to or from the AWS Infrastructure, it includes the following services:

AWS Database Migration Service AWS SnowBall Networking and Content Delivery Services The Networking and Content Delivery domain is used for isolating your network infrastructure, and content delivery is used for faster delivery of content. It includes the following services:

Amazon Route 53 AWS CloudFront Management Tools The Management Tools domain consists of services which are used to manage other services in AWS, it includes the following services:

AWS CloudWatch AWS CloudFomation AWS CloudTrail Security & Identity, Compliance Services The Security & Identity, Compliance domain consist of services which are used to manage to authenticate and provide security to your AWS resources. It consists of the following services:

AWS IAM AWS KMS AWS Shield Messaging Services The Messaging domain consists of services which are used for queuing, notifying or emailing messages. It consists of the following domains:

Amazon SQS Amazon SNS Amazon SES Amazon Pinpoint What is AWS | AWS in 10 Minutes | AWS Tutorial For Beginners | AWS Training | Edureka

To learn more about the products of AWS, you can refer to our Amazon AWS Tutorial, which contains detailed information about all of these services.

You have a fair idea now about what is AWS, and the services which are covered in AWS, let’s go ahead and straightaway apply this knowledge to build applications. You might feel that you don’t know much about AWS, but then,

Sometimes you have to run before you can walk!

Keeping that in mind, let’s understand how does one build applications in AWS:

How to build applications in AWS? First and foremost, you should analyze, what is your application about? Is it something that requires you to be worried about the underlying infrastructure? Is it something that requires a database? Is it something that will require monitoring?

So, once you know all the requirements about your application, you can pick the domain, and hence choose a service.

Like for example, you want to deploy an application in AWS, which does not require you to worry about the underlying architecture, which service will you choose?

Well, in the compute section there is this service called Elastic Beanstalk. You just upload your application, and AWS does the rest for you. It’s that simple!

Of course, you wouldn’t know about any of these services without using them right? That’s why AWS came up with an amazing free-tier option.

Who is eligible for a free tier? Every customer from the time he registers on AWS receives the free tier option, and is eligible for the same till 1 year from the time he registers.

How shall this help?

You can try every application in AWS and learn! The more you practice, the more you learn, what is AWS.

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Conquering APIs: My Experience with Keploy Fellowship

vaibhavx42 — Fri, 17 Mar 2023 06:58:12 +0000

API development can be a daunting task, especially for those new to the field. I can attest to the fact that I felt this way since the API's complexity seemed to be a mental block that I was unable to overcome. But afterward, a buddy informed me about a remote fellowship at Keploy where I could discover everything there is to know about APIs, and I seized the chance.

Experience

I'll never forget the first time I heard about Keploy Fellowship. I was like, "APIs? Postman? End-to-end testing? Sounds like a blast!" Little did I know I was in for the ride of my life.

We attended 1.5-hour-long sessions that were filled with learning and fun. Our instructors, Ankit, Nishant, and Animesh, were like knights in shining armor, swooping in to save us from the complexities of APIs.

Every session was like a journey, starting from the basics of HTTP and how the internet works to building our APIs and learning the mysteries of Go. And just when we thought we were starting to get the hang of things, we were hit with homework assignments. But our fearless instructors were always there to help us, solving our queries and un-sticking us from any hurdles.

The Keploy community was a huge help too, always there to lend a hand and offer support. And before we knew it, we were API experts, building our projects and ready to conquer the world!

Looking back, I can safely say that Keploy Fellowship was one of the most challenging and rewarding experiences of my life. I may never be able to look at APIs the same way again, but I'll always be grateful for the memories and the knowledge I gained.

(PS - People from Keploy are pretty friendly and nice and that makes the fellowship super enjoyable)

Let's Understand Keploy

Keploy is a developer tool that helps simplify and streamline the process of testing and data mocking for applications. It works by allowing developers to generate test files and data mocks directly from API calls.

In simpler terms, imagine you're building a new app and you need to test how it will work with real data. Keploy helps you create that data by automatically generating test files and mocks from your API calls. This saves you time and effort, as you don't have to manually create test data or write complicated test files.

Why You Should Apply apply for Keploy Fellowship:

Learn everything about APIs and Postman: Deepen your understanding of APIs and learn how to use Postman effectively.
Enhance technical skills: Get expert guidance and hands-on experience in end-to-end testing and data mocking.
Build a network: Connect with peers and mentors in the industry and grow your network.
Get hands-on experience: Apply your learning and develop real-world skills through practical projects and assignments.

Conclusion

In conclusion, the Keply Fellowship Program offers a unique and valuable opportunity for individuals to grow their skills and advance their careers in the tech industry. With its focus on hands-on learning, mentorship, and collaboration, participants are given the tools and support they need to succeed. My personal experience with the program has been incredibly rewarding, and I have gained invaluable knowledge and insights that I will carry with me for the rest of my career. I highly recommend the Keply Fellowship Program to anyone looking to boost their tech skills and take their career to the next level.

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Postman Student Expert

vaibhavx42 — Fri, 17 Mar 2023 06:56:21 +0000

Hi everyone this is priyanka I Just received Postman Student expert badge from @getpostman

and here i am with my next blog On how you can become Next Postman Student Expert

Excited ? To verify my badge

https://api.badgr.io/public/assertions/9SWGyPprSmyNJ26NVZyQEQ?identity__email=priyankaafssulur%40gmail.com

Have a look at above link Now without wasting much of time lets get started

So first what is postman?

Postman is a popular API client that makes it easy for developers to create, share, test and document APIs. This is done by allowing users to create and save simple and complex HTTP/s requests, as well as read their responses. The result - more efficient and less tedious work. So basically its a collaboration platform for API development. Postman's features simplify each step of building an API and streamline collaboration so you can create better APIs—faster

Why Postman?

It's Free and Easy to Start Wide support for all APIs and Schemas It's Extensible Support and Community(Which include Postman student expert and other community leads etc...)

To become Postman Student Expert You can go through this link

https://www.postman.com/company/student-program/

And apply here https://docs.google.com/forms/d/e/1FAIpQLSeXYUXbptNSve8dzquJzV6O3PtfWaSqx-Y1BjemYoM9m9168A/viewform

Then After Applying you will receive another mail related to what is the further steps that what is to be done

Now you need to fork a repository made to be a postman student expert

https://www.postman.com/postman/workspace/postman-student-program/collection/9065401-a1abb6df-a8ae-4841-baf4-79d6e67f7934?ctx=documentation

Then you need to Start training and after you send the first request Go to visualize tab for better understanding and for the next steps to be performed

After completing all the skill test and the Test collection You need to fill a form and Hola you are now Postman Student Expert

Also There is one more challenge going on Related to this that is 30 days of Postman

Have A look Here for more details :- https://www.postman.com/postman/workspace/30-days-of-postman-for-developers/documentation/1559645-1ac59603-2ea0-4568-ac54-9f793bc06456

I Just started with this challenge Hope to complete it Soon

Happy Learning !!!

Do Feel free to reach out to me for any kind of help

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How I became Google Cloud Certified

vaibhavx42 — Fri, 17 Mar 2023 06:56:00 +0000

Introduction

The Google Cloud Digital Leader certification is the fundamental Google Cloud certification and an excellent way to expand your basic yet introductory technical understanding of Google Cloud.

The exam is the perfect starting point for those looking to expand their knowledge of cloud computing and how Google Cloud products and services can be utilized to achieve an organization's objectives. It serves as a fundamental certification and is comparable to the AWS Cloud Practitioner and Azure Fundamentals certifications.

Preparation

When a friend first told me about the Google Cloud Digital Leader certification, I knew I had to give it a shot. So, I scheduled the exam for December 2022 and began my preparation in October.
Despite the tight timeline, I was determined to put in the necessary effort to ensure success. And let me tell you, my hard work paid off! I passed the exam with flying colors.
My secret weapon? The official guides provided by Google. I also utilized some supplementary materials to supplement my learning, but those guides were my trusty sidekick throughout the preparation process.

It's safe to say, the Google Cloud Digital Leader certification is the perfect opportunity for anyone looking to enhance their skills and advance their career in the field of cloud computing

Exam Day

I was ready to conquer the Google Cloud exam on December 30th, but it seemed the invigilator had other ideas. It was like a horror movie where the villain keeps delaying the climax. But thanks to the extra study time, I was more than prepared.

As I was about to submit my exam, my internet suddenly crashed. It felt like my 1.25 months of preparation went down the drain. But thanks to the helpful Kryterion support team, they were able to submit the exam on my behalf and saved me from a total meltdown.

Results & Blockchain Verification

After completing the exam, be aware that it may take several business days for your results to be reviewed. I took the exam on Friday and received an email confirming that I had passed the following Monday.

One unique aspect of Google's certifications is that they use Accredible, a digital badge and certificate platform built on blockchain, to manage their certification programs. This enables recruiters or your current employer to verify your certification in real-time using blockchain technology. You can check my certification if you would like to test the verification validation yourself.

RESOURCES

I primarily relied on the official guides provided by Google. In addition, I also utilized some supplementary materials which are:

Exam Pro - This site provided a wide range of materials, including lectures, practice questions, and mock exams, which helped me to study effectively.
Exam Topic - It was necessary to understand the scenario-based questions I could expect to encounter on the test, Exam topics helped in providing those questions.
NOTES - Flashcards and notes made by Sarah Walker-Leptich were extremely helpful for revising the key concepts on a daily basis. These notes and flashcards were a great way to quickly review the material and refresh my memory before the exam

Conclusion

Keep calm. The exam is not as difficult as you may imagine.
Make use of the option to review questions later.
Answer all questions, as there is no penalty for incorrect answers.
When faced with questions you are unsure of, try eliminating the answer choices to narrow down your options.
If you encounter any issues during the exam, don't worry. Reach out to a specialist who can help resolve the problem or schedule your exam for a more suitable date based on your availability.

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