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There is a decent chance that if you have used Linux operating systems then you might have encountered the three famous data streams known as stdin, stderr and stdout. All these are different in their functions and have their own uses but one thing common between all three of them is that they are data streams that the shell creates. Let's understand more about what data streams actually mean and how they are beneficial. In terms of computing, a data stream is something that gives us the ability to transfer data from a source to an outflow and vice ... Read More
A thread is a lightweight unit of execution within a process and represents the basic unit of CPU utilization. It consists of a program counter, a stack, and a set of registers, allowing multiple execution paths within a single process. Process with Multiple Threads Process Code Section Data Section Files (shared resources) Thread 1 PC, Registers Stack Thread 2 ... Read More
The trend towards multicore systems continues to place pressure on system designers and application programmers to make better use of multiple computing cores. Designers of operating systems must write programming algorithms that utilize multiple processor cores to enable parallel execution as shown below − Parallel Execution on a Multicore System CPU Package Core 1 Task A Task B ... Read More
Internet radio has become a popular way of listening to music and news from all over the world. There are many internet radio players available for Linux, but finding the right one can be a challenge. Open source internet radio players for Linux are free and customizable, making them an excellent option for Linux users who want to personalize their listening experience. In this article, we will discuss the best open-source internet radio players for Linux and their features. We'll also talk about how to install and use these players on your Linux machine. Top Open Source Internet ... Read More
Secure Shell (SSH) is a cryptographic network protocol that provides secure remote access and file transfer over unsecured networks. It encrypts all traffic between hosts, ensuring data confidentiality and integrity. SSH is widely used by system administrators, developers, and IT professionals to remotely manage servers, access files, and execute commands. Understanding the SSH Authentication Error The "Too Many Authentication Failures" error occurs when an SSH server receives multiple failed authentication attempts in quick succession. By default, SSH servers limit authentication attempts to 6 tries within a short period. When this limit is exceeded, the server denies further attempts ... Read More
When we talk about opening a file in Linux, the process varies depending on the programming language and API being used. However, most high-level languages eventually call either the C library functions or directly invoke the Linux open() system call. This article focuses on what happens at the kernel level when a file is opened in C on a Linux system. The sys_open() System Call At the heart of file opening is the sys_open() system call. When you call open() in C, it eventually triggers this kernel function found in fs/open.c: int sys_open(const char *filename, int ... Read More
Document scanning has become an essential feature for smartphone users who need to digitize physical documents on the go. With numerous scanning applications available on the Google Play Store, choosing the right one can be challenging. Modern Android phones with high-quality cameras can capture excellent images, but converting these images to PDF or Word formats requires specialized applications. Among the various scanning applications available, CamScanner stands out as one of the most popular and feature-rich options for Android users. It offers both free and premium tiers, making it accessible to users with different needs and budgets. ... Read More
Pthreads refers to the POSIX standard (IEEE 1003.1c) that defines an API for thread creation and synchronization. This is a specification for thread behavior, not a specific implementation, allowing operating system designers to implement it according to their requirements. The Pthreads API provides a standardized way to create multithreaded programs in C, enabling concurrent execution of multiple threads within a single process. Each thread shares the same memory space but can execute different parts of the program simultaneously. How Pthreads Work In a Pthreads program, separate threads begin execution in specified functions. The main thread starts in ... Read More
When running a bash script on Linux, it's important to ensure that only one instance of the script is running at a time. This is especially important for scripts that perform critical tasks, such as database updates or email sending. Running multiple instances of the same script simultaneously can cause conflicts, data loss, and other errors. In this article, we will discuss different methods to ensure that only one instance of a bash script runs on Linux. Using Flock One way to ensure that only one instance of a bash script runs on Linux is to use the ... Read More
Bash is a powerful shell scripting language used on Linux and Unix systems. One of the most common tasks in shell scripting is evaluating arithmetic expressions. This article explores various methods to evaluate mathematical calculations in Bash scripts. Methods for Arithmetic Evaluation Bash provides several ways to evaluate arithmetic expressions. While the traditional expr command exists, modern Bash offers more efficient built-in methods. Using expr Command The expr command evaluates expressions passed as arguments: $ expr 2 + 3 5 Using Arithmetic Expansion $((...)) The preferred method uses double parentheses for ... Read More