Unix Operating System Tutorials

UNIX operating system articles, tutorials and resources
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1. What Is Kernel? A kernel is a central component of an operating system. It acts as an interface between the user applications and the hardware. The sole aim of the kernel is to manage the communication between the software (user level applications) and the hardware (CPU, disk memory etc). The...
Sometimes you must have noticed that you have 1gb of data to write. But you are unable to decide that what media should you use. Because 1 DVD can be more than enough required and 1 CD is not enough for writing the data. And if you use another CD, that would be probably half free. So, you will be...
Introduction WINE (Wine Is Not an Emulator) is a free software application that aims to allow Unix-like computer operating systems to execute programs written for Microsoft Windows. Wine also provides a software library known as Winelib against which developers can compile Windows applications...
Netcat (also known as ‘nc’ or ‘Swiss Army knife’) is a networking utility used for reading or writing from TCP and UDP sockets using an easy interface. NetCat is designed as a Dependable ‘back-end’ device that can be used directly or easily driven by other programs and scripts. Netcat is a treat to...
I have been using linux for 2 years now, and I can tell you that I learn something new virtually every day. And a few of those things I have learned are very rare to be seen all the time. Here are a few of them. If you are using Redhat's netcfg utility to connect to the internet and you are sick...
Shell Tips & Tricks Create A Command Alias Most of us use 'ls -l' so, will it not be easier to have a smaller command to show us long listing, add the following line to ~/.bashrc alias ll='ls -l' Using it # ll
SSH is a abbreviation for Secure Shell is a network protocol that allows data-exchange between devices on the network..This is mainly used in linux OS's to access shell accounts , shell commands etc... SSH was mainly designed as a replacement modification to telnet etc..other insecure remote shells...
Concept: The UNIX kernel can keep track of many processes at once, dividing its time between the jobs submitted to it. Each process submitted to the kernel is given a unique process ID. Single-tasking operating systems, like DOS, or the Macintosh System, can only perform one job at a time. A...
In this tutorial of mine I am demonstrating some bash commands with some example scenarios/questions and their solutions.... What is Bash:- Bash or Bourne Again Shell is a reimplementation of Bourne shell... Bash is the default shell that comes with most of the linux distributions out...
Command line skills are something you pick up over time. When something needs to be done, you work out how, and from then on you know how to do it. Few take the time to systematically learn the ins and outs of the tools at their disposal, however, and so may not be aware of all the possibilities of...
Part I - Shell Tips & Tricks Clear and Disable Bash History Use the Bash inbuilt history command: history -cTo prevent writing of your Bash history to the history when you log out: unset HISTFILEAmpersand (Background Jobs)
Introduction Everyone of us might have come across a lot of text editors each of them having their own special features and style. GNU Emacs, apart from being a text editor, is a wonderful software which makes us believe it to be a mini operating system. Like other softwares, Emacs is...
GDB is GNU Project Debugger its basically is a debugger and allows you to see inside the program flow, control structure, working, code and we will see how we can do that. How to work with GDB We will we using a basic debugMe.c program throughout this tutorial helloworld.c ...
This is continuation of my previous articles .. Please don't miss them :- Bash Simple Tricks Bash Simple Tricks (continuation) Again I am following a question – solution approach to demonstrate my scripts.. Scripts
Cron is a Unix/Linux etc .. utility thaat allows the tasks to be run at specific time as well as at specific intervals..The job that the program does are know as CronJobs and are stored in a table (Cron Table).. Using To schedule any task with cron we can use crontab command in Unix.. Lets...
You might have studied various mechanisms through which two processes interact on same host. For example message queues, shared memory etc. But what about interaction between two process running on two different hosts (lets say on a LAN or WAN). Here comes the concept of network programming where...
du is an abbreviation for (Disk Usage), this command calculates & returns the size of entire directory tree as well as of individual files. df is an abbreviation for (Disk Free), it's job is to calculate and return the amount of free space of a disk/partition. These two commands report space...
Introduction Many times we write programs which runs many instances of itself, either while using fork or we manually run many copies of the same program, so during the development stage we may need to kill all running instances and modify the program and re-run, or there may be other situations...
xargs is an utility which is used to build & execute command-lines. xargs reads from the standard input (STDIN) space, tab, newline & end-of-file (EOF) delimited strings and executes the specified utility with the strings as argument(s). Most utilities/systems have a limit on the maximum no. of...
Now let us try to do same in Unix as we have discussed in the following Article - Splitting String Using Delimiter in Oracle In Unix it is pretty simple. We can use below commands to split echo "GO 4 EXPERT|99999|20130101|20131231"|cut -f1 -d"|" or echo "GO 4...