AWS Global Infrastructure Explained
AWS global infrastructure is divided into regions. A region is a locations that hosts a collection of AWS data centers. Each region is a completely separate entity. AWS consumers can…
Overview of Key AWS Services
Following is a snapshot of key AWS services: Compute Amazon EC2: virtual computing AWS Lambda: serverless computing Amazon Elastic Container Service ECS: containerized computing Storage Amazon Elastic Block Store (EBS):…
Amazon Elastic Compute Cloud – EC2
Elastic Compute Cloud (EC2) refers to compute (server) resources. In AWS, servers are called Amazon EC2 instances or just “instances”. You can install application instances, web instances, database instances, gaming…
What is the difference between include, include_once, require, and require_once in PHP
PHP provides four functions which enable you to insert code from other files. * include()* require()* include_once()* require_once() All four can take a local file or URL as input. None…
Java Linked List
The Internet is full of code examples on how you can create your own LinkedList class. Java provides and very easy to use class LinkedList. Following is an example on…
MySQL column enumeration example
Problem: You are building a database and you have a field that can accept only certain responses. For example, there is a Gender column which accepts only M or F…
How to encrypt a string in PHP
The following code encrypts a string. crypt() function encrypts the string. The last line prints the encrypted string. There is no such function called decrypt(). This is because crypt uses…
Perl $_ vs. $_[]
For a beginner, Perl can be a frightening language. This is largely due the numerous special variables used in perl. Once a programmer understands the special variables, he/she begins to…
Installing and Using SSH on Unix/Linux
SSH client can be downloaded from www.openssh.com. To install, do the following: To use, type the following:
for loop in bash
For loops in bash a similar to commonly used languages such as Perl and C. bash loops do not use curly brackets for body demarcation. Example 1 Loop start from…