Tuesday, November 19, 2019

Top 10 Gift Ideas for Programmers, Software Engineers, and Tech Geeks

My friend circle has a lot of programmers and non-programmers. When it comes to buying gifts for birthdays, anniversary, or holidays, I receive a lot of queries from my non-programmer family and friends about what to buy for a programmer? Well, buying a gift is easy but choosing or finding the right gift for someone is really really tough. I have had this experience when it comes to buying gifts for kids. I know they like toys but my wife told me to buy something more valuable, which not only keeps them engaged but also provides value, help them in learning and they appreciate every time they use. That's a lot to cater to one gift, but that's the perfect gift, isn't it?

Top 10 UNIX and Linux System Programming Books- Best of Lot, Must Read

I have been sharing programming books in this blog for a long time, starting with core Java; I moved to other related technology, like Spring, Design patterns, Data Structure and Algorithms, etc. Today, I am going to share some of the best UNIX and Linux programming books. The list contains some of the must-read UNIX books from great writers like Sir Richard. Stevens, Sir Brain Kernighan, who has contributed so much to the development of the UNIX operating system. Most of the books on this list are timeless,  classic, and don't age with time, much like UNIX, which is around for the last 40 years, and I am sure it will be around for the next 40 years, or maybe forever.

Sunday, November 17, 2019

How to send HTTP request using curl and wget command from Linux and UNIX? Example Tutorial

You can use either curl or wget command to send HTTP requests from UNIX or Linux operating system. Both commands allow you to send GET and POST requests, which means you can also call REST web services.  I have a Java web application, which runs on Linux and exposes WebServices. I was writing a UNIX script to download In some data from that web service when I hit by the question, how do I make an HTTP call from UNIX? What is the UNIX command should I use? If you are also facing the same problem, then you have come to the right ht place. Basically, you can use two UNIX commands to make the HTTP request, wget, and curl.

Top 5 Books to Learn Scala and Functional Programming - Best of Lot

Scala is one of the relatively new programming languages which encompasses best practices of many programming languages. The biggest strength of Scala is that it provides a beautiful blend of object-oriented programming and Functional programming. So, you can not only construct elegant class hierarchies for maximum code reuse and extensibility, but you can also implement their behavior using higher-order functions. It has a concise syntax with less ceremony, which also makes it ideal for scripting but doesn't underestimate its power. Like Java, Scala has also used for mission-critical applications by technical giants like Twitter, LinkedIn, and Intel.

Friday, November 15, 2019

10 Example of find command in UNIX and Linux

The find command is one of the most versatile commands in UNIX and Linux, and I used it a lot in my day to day work. I believe having a good knowledge of find command in UNIX and understanding of its different options and usage will increase your productivity a lot in UNIX based operating system, e.g. Redhat Linux or Solaris. If you are a QA, support personnel, and your works involve lots of searching text on Linux machine or if you are a Java or C++ programmer and your code resides in UNIX, find command can significantly help you to look for any word inside your source file in the absence of an IDE.

Thursday, November 14, 2019

10 Example of lsof commands in Linux and UNIX

It's been a long time since I have written anything on UNIX or Linux commands. Still, today, I'll talk about the lsof command, a utility command every system admin and developers love. The lsof command stands for list open file descriptors, and as the name suggests, it is used to find open files by the process. Since almost everything in UNIX are file, you can use lsof command to find an open regular file, a directory, a symbolic link, a special block file, an NFS mounted file, a socket stream, a shared library, a special character file, a regular pipe, a named pipe, an internet socket, a UNIX domain socket, and many others. I have mostly used it to find all the files opened by a particular process, which I will show you in the next section.

Tuesday, November 12, 2019

10 JDK 10 Features Java Developers Should Know

Hello Guys, while we all are talking about Java 9 and some people are yet to adopt Java 8 in their projects, here comes the new release of Java, the JDK 10. It's available to download now on Oracle's website. This is the first release in the latest release schedule, where you have a new Java release every six months, I know it's quite early, but that's a reality now. Apart from 6 monthly release, Every 3 years there is an LTS release, which is sort of major Java release. The next LTS release is Java 11 which should be out in September. So you can aim for that. Then you can update three years after that to the next LTS release.

Monday, November 11, 2019

How to Enroll on Spring Professional Certification (VMware EDU-1202) and Schedule Exam

So, you have been preparing for Spring certification for quite a sometime, and now you feel you are ready to take the exam, and it's time to buy the Spring certification voucher and schedule your exam. In this article, I'll show you how to buy the Spring certification voucher online. But, before purchasing a voucher, I would like to remind you that the Spring certification (VMware EDU-1202) voucher is only valid for 90 days, after that it will expire. So, it's best to buy the voucher only if you are ready for the exam i.e. you have gone through several Spring Mock tests and practice tests given in Spring study guides and you are consistently scoring over 80% on them.

Sunday, November 10, 2019

How Spring MVC Framework works? How HTTP Request is processed?

One of the frequently asked Spring MVC Interview questions is about explaining the flow of web request i.e. how an HTTP request is processed from start to end. In other words, explaining the flow of request in Spring MVC. Since many of my readers ask this question time and again, I thought to summarize the flow of request processing in a short article. It all starts with the client, which sends a request to a specific URL. When that request hits the web container like Tomcat it looks into web.xml and finds the Servlet or Filter which is mapped to that particular URL. It the delegate that Servlet or Filter to process the request. Since Spring MVC is built on top of Servlet, this is also the initial flow of request in any Spring MVC based Java web application.

Saturday, November 9, 2019

find + du + sort + head command example in Linux - How to search large files and directories in host to free some disk space

Hello guys, 100% full disk space is a common problem and as a programmer or Linux user, you often need to free disk space by deleting biggest files and directories. In order to do that, you need to know some Linux find command examples to list and delete some biggest files and directories and that's what you will learn in this tutorial. As a Java developer, you also need to also support your application, most of which mostly run on Linux machines. Though production is monitored by the dedicated support teams and they receive regular alerts on the status of file system space, they often come running to you or the developer responsible about what to do when disk space is almost full or reaching 100%.

Thursday, November 7, 2019

Do you Need to Pass OCAJP before taking OCPJP - Core Java Certification from Oracle

Even though we now have Java 11 certification, I know many Java developers who are going for Java certification like Java SE 8 Programmer 1 and 2, also known as OCAJP 8 and OCPJP 8 with exam code 1Z0-808 and 1Z0-809. Even though Oracle split Java certification into 2 after acquiring Sun Microsystem in 2010, there is still confusion among Java developers whether they need to pass just one OCAJP exam or both OCAJP and OCPJP exam to become a certified Java developer. Well, The short answer is Yes, if you want to become a Java certified engineer then you need to pass both OCAJP and OCPJP, but the long answer depends upon your situation, e.g. whether you hold any previous Java certification or not, which we'll discuss in the second section.

Wednesday, November 6, 2019

Top 5 Books for Programming/Coding Interviews - Best of lot

If you are preparing for Programming Job interviews and looking for some of the best books for programming questions, then you have come to the right place. In this article, I am going to share a couple of good books to prepare coding, software design, and data structure algorithm questions, which are essential for any coding interviews. Though a programming interview also explores other areas of software development, e.g., the programming language, you would be mainly used in your project, like, C++ or Java. The database and SQL based questions, the operating systems, and UNIX related questions, some of the software design and object-oriented design pattern questions, and much more, but coding based questions form the core of programming interviews.

Monday, November 4, 2019

How do you find length of a Singly Linked list using Loop and Recursion

Hello guys, here is one of the classical programming questions how do you find the length of a linked list using recursion and without recursion. This is not about the LinkedList class of Java API but the linked list data structure, which is made of nodes that contain both data and address of the next node. In order to calculate the length, you need to count all nodes in the linked list. Since it's a singly linked list you can only move in one direction from the head to tail.  This coding problem was asked to me on my first interview with a multinational Investment bankAfter that, this question has been asked to me on several occasions in other Programming Job Interviews as well.

Top 5 Websites to Learn Python Coding for FREE - Best of Lot

Believe it or not, but Python has inspired many people to learn to code and its continually inspiring them. I know a handful of people who are learning Python for different reasons, starting from web development to machine learning. I have seen new people learning Python to write web apps using Django, create a Machine learning Model using Python, and just to write some handy scripts to automate the boring stuff. Python is currently the world's #1 programming language and its popularity is growing every passing day, thanks to Data Science and Machine learning and awesome Python libraries like Pandas, NumPy, and TensorFlow.

Saturday, November 2, 2019

5 Websites to Learn SQL Online for FREE

The SQL is one of the most important skills for any programmer be it a Java, C++, Python, JavaScript, or Ruby developer. Almost 95% of the Java applications use a relational database in their back-end and almost all web applications use the database. In recent years, one of the most common way to learn any programming skill is online, at your comfort of the office or home and SQL is no different. Learning SQL online has another advantage of a quick head start because you don't need to install a database and create tables to write some SELECT queries. The installation and setup is definitely a tough part for beginners and I have gone through that pain every time I have to learn a new database.