Operating System Articles - Page 174 of 199

This article will guide you to understand the Zombie process and Daemons, and also help us to find the process which is running in the background.What is Zombie Process?When a process ends the execution, then it will have an exit status to report to its master process. Because of that little bit of information, the process will remain in the OS process table as a zombie process, which indicates that it is not to be scheduled for future, but this process cannot be completely removed or the process ID will not be used until the exit has been determined and ... Read More

This article we will teach you to schedule a cron job to be executed at a specific time in a day.General Syntax of a Cron JobMIN    HOUR    Day of month    Month    Day of Week    Command 0-59   0-23       1-31          1-12       0-6       linux command or scriptTo see the list of cron jobs which exists on the machine, run the below command# crontab -u test1 -l no crontab for test1To Add the New Cron Job to Test1 User, run the below Command #crontab -u test1 ... Read More

Green threads are created and scheduled by Virtual machine without using OS libraries. “Green” was the project code name of the thread project which was developed by the Java, therefore the name of the thread is “Green”. It can not make use of multiprocessor.On the other hand, Native threads are created and scheduled by Kernel of operating system. It can swap between threads from running thread to non-running thread. All modern OS supports native thread. Sr. No.KeyGreen ThreadNative Thread1Basic Green threads are created and scheduled by Virtual machine without using OS librariesNative threads are created and scheduled by Kernel of operating system2Platform Dependent It ... Read More

Are you working as a Linux Admin? Do you generally defend script documents or any important files? You might be aware that, Chattr (change Attribute) is a command line Linux utility that is used to set/unset exact attributes to a file in Linux process to comfortable unintended deletion or change of major files and folders, although you’re logged in as a root user.This article helps you to look after your records or folders that may support in disallowing an unauthorized user to delete your touchy contents.Protecting FileIn the below example abc.txt is the file nameProtecting a fileTo protect file, use ... Read More

Everpad is a fantastic tool for work, but it is also a great tool outside of the workspace. It is an open-source client for the note taking. Although there isn’t an official Everpad client available for Linux, by installing Wine, you can use the exact Everpad client. This article describes “how to install Everpad client in Ubuntu”It supports Unity Lens which allows you to search through your Everpad, then click to open them for additional editing. From the application, you can create and manage all of your Everpad from one single place.Installing EverpadTo install Everpad, we require Everpad ppa  from ... Read More

Bower is a bundled supervisor for the web and offers a conventional technique for the drawbacks in entrance-finish package management. It basically maintains and monitors all packages and examines new updates. Bower also makes use of a take place file called bower.Json to keep track of applications. This article explains about -“How to install bower on Ubuntu”.To install bower, we require pre-installed Node.js and NPM. To verify the node.js version, use the following command-$ node -vThe sample output should be like this-v6.9.2To verify the NPM version, use the following command$ npm -vThe sample output should be like this-3.10.9If you wants ... Read More

Cat command is a well known Unix utility that reads files sequentially. Writing them to conventional output. The name is derived from its function for concatenating and listing the documents. Tac (that is “cat” backwards) concatenates every record to traditional output much like the cat command. However in opposite: line-by means of-line, printing the last line first. This article explains about “How to use ‘cat’ and ‘tac’ commands with examples”.The basic example of cat command should be like this –$ cat text.txtThe above command is to read files and display them to stdout, meaning to display the content of files ... Read More

This article will teach you on, how to schedule a corn job for executing a script or command or shell script at a particular time every day. As a system administrator, we know the importance of running the routine maintenance jobs in the background automatically. The Linux corn utility will help us to maintain these jobs to run in the background.General Syntax of a Cron JobMIN HOUR Day of month Month Day of Week Command 0-59 0-23 1-31 1-12 0-6 Any Linux command or scriptTo see a list of cron jobs which exists on the machine, run the below command ... Read More

The grep command is used to search text or scans the given record for lines containing a match to the given strings or words. Use grep to search for lines of text that match one or many regular expressions, and outputs only the matching lines. Using the grep command, we can recursively search all files for a string on a Linux.Syntax of is shown as below-$ grep -r "word"For example, for searching “Linux” word in Downloads directory. The command should be like this~/Downloads$ grep -r "Linux"The sample output should be like this –zookeeper_installation.htm:Any of Linux OS − Supports development and ... Read More

In this article, we will learn about how to install and configure the Nginx Web server. Nginx is the most popular web server where some of the most popular and high traffic sites are hosted where it is more friendly and secured than Apache and it is also used as a web server.PrerequisitesUbuntu 16.04 installed on the machine with a non-root user with sudo permissions on the machine.Installing the Nginx in MachineWe can install the Nginx, which is available on Ubuntu’s default repository so can directly install the Nginx using the apt command.Before we install the Nginx we needed to ... Read More