Tuesday, November 19, 2019

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.

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.

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.

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.

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.