Data Structure
Networking
RDBMS
Operating System
Java
MS Excel
iOS
HTML
CSS
Android
Python
C Programming
C++
C#
MongoDB
MySQL
Javascript
PHP
Economics & Finance
Micro kernel is one of the classifications of kernel architecture and is often represented as μ-kernel. It is a minimalist operating system design that provides only the most essential services in kernel space, moving most operating system functionality to user space as separate processes. The core functions provided by a micro kernel are − Inter-process communication (IPC) − Message passing between processes Thread management − Basic thread creation and scheduling Low-level address space management − Memory protection and virtual memory basics In the micro kernel architecture, user services and kernel services are kept in different ... Read More
Scheduler activations is a technique that enables effective communication between the user-thread library and the kernel. This mechanism provides an elegant solution to the problem of managing user threads efficiently while maintaining kernel awareness of thread activities. How Scheduler Activations Work The kernel provides an application with a set of virtual processors (also called Lightweight Processes or LWPs). The application can then schedule user threads onto these available virtual processors. The key innovation is that the kernel must inform the application about certain critical events through a mechanism called upcalls. Scheduler Activations Architecture ... Read More
The grep command is used to search text and scan files for lines containing a match to given strings or words. It searches for lines that match regular expressions and outputs only the matching lines. Using grep with the recursive option, we can search through all files in a directory and its subdirectories for specific strings on Linux. Basic Recursive Search Syntax The basic syntax for recursive searching is: $ grep -r "search_term" /path/to/directory If no directory is specified, grep searches the current directory: $ grep -r "search_term" Examples ... Read More
In Linux system administration and data processing, displaying specific columns from text files is a fundamental task. Whether you're analyzing log files, processing CSV data, or extracting information from command outputs, knowing how to select and display specific columns efficiently is essential. This tutorial covers various methods to display columns using the awk and cut commands, two powerful text processing tools available in all Linux distributions. Display Single Column Let's start with a sample file containing the output of the ls -l command in long listing format: $ cat input.txt -rw-r--r-- 1 jarvis jarvis 200M ... Read More
Dockerfile is a text file containing a series of instructions that define how to build a Docker image. These instructions are executed sequentially when you run the docker build command, creating layers that form the final image. Understanding key Dockerfile instructions is essential for creating efficient, maintainable, and secure container images. In this article, we'll explore the most important Dockerfile instructions that every developer should master to build optimized Docker images. FROM The FROM instruction specifies the base image for your Docker image and must be the first instruction in any Dockerfile (except for ARG instructions that ... Read More
If you're a Linux user who loves to listen to music, then you're in luck! There are many command line music players available for Linux that can enhance your listening experience. Here are the top five command line music players for Linux − CMUS CMUS is a lightweight, fast, and powerful music player for terminal. It has a simple and intuitive interface that allows you to quickly navigate through your music library. CMUS supports various audio formats such as MP3, FLAC, and WAV, among others. One of the standout features of CMUS is its ability to handle large ... Read More
Linux provides a powerful command-line interface (CLI) that enables users to download files and browse websites efficiently. This article covers eight essential command-line tools that every Linux user should know for downloading files and web browsing tasks. Wget Wget is a free utility for downloading files from the web. It supports HTTP, HTTPS, and FTP protocols and can download files from single or multiple URLs. You can also use it to mirror entire websites or specific portions. Basic Syntax wget [options] [URL] Examples Download a single file − wget https://example.com/file.zip ... Read More
FTP (File Transfer Protocol) is a standard network protocol used to transfer files from one host to another over a TCP-based network, such as the Internet. An FTP server allows users to upload and download files over a network, and it is an essential tool for file sharing and remote file access. In this article, we will guide you through the process of installing an FTP server on Ubuntu with vsftpd, one of the most popular FTP servers available. Step 1: Install VSFTPD The first step in installing an FTP server on Ubuntu is to install the vsftpd ... Read More
When running applications in Docker containers, you often need to connect from the container to services running on the host machine's localhost. For example, if you have an Nginx container that needs to access a MySQL database running on your host's localhost (127.0.0.1), the default container networking won't allow this connection since the container has its own isolated network namespace. This article explains different methods to establish connectivity between Docker containers and host services, with solutions varying by operating system and networking requirements. Method 1 − Host Network Mode (Linux) The simplest solution on Linux is using ... Read More
A thread is a lightweight unit of CPU execution within a process. It comprises a thread ID, a program counter, a register set, and a stack. Multiple threads belonging to the same process share the code segment, data section, and operating system resources like open files and signals. A traditional heavyweight process has a single thread of control. However, if a process has multiple threads of control, it can perform more than one task concurrently. Many modern software applications are multithreaded, implementing the application as a single process with several threads of control. For example − A word ... Read More