What is abstract Classes

As from name it seem like something that is¬†hidden. Yes nature of the abstract classes are same. Abstract classes are those classes which can not be directly¬†initialized. Or in other word we can say that you can not create object of abstract classes. Abstract classes always created for inheritance purpose. You can only inherit abstract... Continue Reading →

Insertion Sort example and algorithm

Sorting is the process of arranging a list of elements in a particular order (Ascending or Descending). Insertion sort algorithm arranges a list of elements in a particular order. In insertion sort algorithm, every iteration moves an element from unsorted portion to sorted portion until all the elements are sorted in the list. Step by... Continue Reading →

Selection Sort algorithm

Selection sorting is conceptually the most simplest sorting algorithm. This algorithm first finds the smallest element in the array and exchanges it with the element in the first position, then find the second smallest element and exchange it with the element in the second position, and continues in this way until the entire array is... Continue Reading →

Bubble Sort Algorithm in data structure

Bubble sort algorithm starts by comparing the first two elements of an array and swapping if necessary, i.e., if you want to sort the elements of array in ascending order and if the first element is greater than second then, you need to swap the elements but, if the first element is smaller than second,... Continue Reading →

The Red Hat distribution of Linux provides a slightly more organized way of managing processes. Instead of hunting and killing them by finding their process id in the process table, Red Hat provides a collection of scripts in the ``/etc/rc.d/init.d'' directory which will allow you to start and stop processes as desired. For example, to... Continue Reading →

Checking Storage Space in linux

Checking Storage Space It is important to check from time to time that adequate free space remains on the storage devices. Use the "df" command to get a report of available space. It will look as follows (information shown is from the Internet server at my place of employment): Filesystem 1024-blocks Used Available Capacity Mounted... Continue Reading →

Cisco Router Configuration Backups

Cisco Router Configuration Backups At my place of employment, we have a WAN connecting several remote locations. These remote locations have Cisco routers connected via ISDN, or in some instances, Centrex data circuits, to provide Internet and WAN connectivity. Cisco router products allow using TFTP ("Trivial File Transfer Protocol") on a network server to read... Continue Reading →

System Shutdown and Restart linux

To shut down the system from a terminal session, sign in or "su" to the "root" account. Then type ``/sbin/shutdown -r now''. It may take several moments for all processes to be terminated, and then Linux will shut down. The computer will reboot itself. If you are in front of the console, a faster alternative... Continue Reading →

Linux Password & Shadow File Formats

Traditional Unix systems keep user account information, including one-way encrypted passwords, in a text file called ``/etc/passwd''. As this file is used by many tools (such as ``ls'') to display file ownerships, etc. by matching user id #'s with the user's names, the file needs to be world-readable. Consequentally, this can be somewhat of a... Continue Reading →


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