View PHP Environment Configuration Settings and Superglobals on a Page
PHP is a great computer and web site scripting language and extremely popular. It is used primarily for developing interactive web sites and many use it for day-to-day programming tasks. There are several versions in general use and sometimes the configuration of PHP between servers and machines needs to be compared. The phpinfo() function is a one line solution to show the current live PHP set up. To show PHP settings simply create a one line PHP web file on the server containing <?php phpinfo(); ?> and point the browser at it. HTML tags are NOT required because the phpinfo() function pumps them out.
Note: phpinfo() outputs a lot of useful information, information that hackers find interesting so use it with care. Ideally do not have the phpinfo() page on a public facing web site. On the occasions you do take precautions to reduce information leakage. Put the page in a password protected directory, do not call it phpinfo.php as this is obvious to hackers (use something more obscure and a reminder to delete it when finished, e.g. quick-config-check.php), finally don’t forget to delete it when the PHP settings have been checked.
A PHP script will need access to other settings that PHP provides, often via system wide globals known as the superglobals. The $_SERVER array provides access to the _SERVER superglobal and is shown by phpinfo() in a table. Occasionally it can be worthwhile viewing such values from another PHP file. This can be done in a few lines of code. The following provides some details on showing PHP settings and global values in web pages.
C# Encryption and Decryption of a String With a Simple Function Call
Cryptography is a big subject area and extremely important for modern software and programs. If you are writing any type of software you need an understanding of software security and methods to keep data, code and users secure. Encrypting data keeps it secure because it hides its meaning, converting the plaintext (or cleartext) to ciphertext. To see the data again you need to decrypt the ciphertext back to plaintext. A simple example is the encryption of passwords to protect them from use by others.
Encryption and decryption of a password or other strings containing data can be done in many ways. There are many character substitution or transposition methods that pre-date the computing era and can be traced back to classical times. Modern computer based methods use symmetric key and asymmetric key mathematical algorithms. There are lots of well established algorithms from which to choose. However not everyone wants to take a course in cryptography just to be able to encrypt a string to hide some data and decrypt it back again. That’s where this example C# encryption and decryption code comes in handy. This code was tested in Visual Studio 2013.
This C# code has been boiled down to an encryption function that takes a plaintext string and passphrase and returns an encrypted string. There is the reverse function that takes the ciphertext and the passphrase and returns the plaintext. This is a quick and easy method of adding some encryption to a C# project, or any .NET project. The encrypt decrypt C# string functions are in a simple class. An example project shows how simple it is to use them. Continue reading
Renaming Websites and Folders in WebMatrix
Using a free package it is possible to develop a website on Windows using Microsoft WebMatrix. This program allows you to run a website on your local Windows computer. When a website is created in WebMatrix it will usually have the name EmptySiteX where X is a number. The name is the same as the folder in which the website files are stored. Where does WebMatrix create this folder? This folder is normally in My Web Sites in the logged on user’s Documents folder:
C:\Users\John Doe\Documents\My Web Sites\EmptySite1
(Tip: Using the WebMatrix settings this default location can be changed.)
Changing a website name in WebMatrix is easy. Open the website in WebMatrix with the Home tab selected. Ensure site folder is visible (select Files or the files icon on the left hand panel to see everything that makes up the site). Bring up the context menu (usually right-click) on the top level folder. Select Rename and enter the new name:
A brief status message is displayed at the bottom of WebMatrix. Then to completed the WebMatrix rename site an edit of the IIS Express applicationhost.config file is required. Continue reading
Running PHP to Test Websites on Windows PCs
PHP is a programming language that is popular for for adding powerful features to websites. What does PHP mean? PHP originally stood for Personal Home Page (after its inventor, Rasmus Lerdorf, wanted more features for his personal website), but now it stands for PHP Hypertext Preprocessor (creating a recursive acronym, which programmers like). PHP is easy to set-up and run on a Windows PC using the free Microsoft WebMatrix, an Integrated Development Environment (IDE) for building websites.
With the free WebMatrix package PHP on Windows is a single click install and allows website testing using IIS Express (the version of Microsoft Internet Information Server for Windows clients). This tutorial assumes that WebMatrix is installed and running on your Windows 7 or higher PC. If not see our article Develop a Website on Windows Using Microsoft WebMatrix to set it up and get a basic website going. Continue reading
GCSE, O-Level and A-Level Computing Subjects
Listed here are Computing and Computer Science school level qualifications available in the UK. The GCSE and O-Level exams are commonly taken at the end of Year 11 (pupils reach the age of sixteen during that year). The A-Level is commonly taken at the end of Year 13 ( pupils reach the age of eighteen during that year). Some colleges offer these qualifications to mature students. Some schools allow pupils to take examinations earlier.
This list deals with computer science qualifications, learning how computers work from the inside and how to program them. The list does not cover ICT, learning how to use computers as a tool in everyday life and the workplace.