Our daily lives are tied to the digital world. Where once we had physical photos, CDs, books and files we now generate and buy the virtual equivalents. We store them on our electronic devices and assume that they will last forever in their digital homes, never needing to use data recovery to restore our virtual assets. But do they last forever?
Data Recovery when Computers Breakdown
A home computer can at any time be holding years of personal information and photos. Items that are irreplaceable to you. How long have you had your computer? The older a machine the greater the chance it will breakdown. When it does break you can feel you have lost part of who you are, this can be a scary time especially if you don’t have a backup. Try and stay calm and read this article from Cheeky Munkey about how to recover data from the hard drive within your computer.
Avoid Hard Drive Data Recovery with Backups
Never get to the point where you need to recover lost files. Most companies that deal with data will have multiple copies of it. Three copies of any file is considered the minimum required. Just as the hip-hop group De La Soul thought that three was The Magic Number you can also use three as the magic number to prevent the need for data recovery.
- The original.
- A local copy on transportable media (e.g. USB drive, external hard drive).
- An off site copy (e.g. cloud storage or on media stored elsewhere, such as a family members house).
Backups are your files insurance policy for when your computer breaks down or is lost. The Internet has made preserving copies of files easier with services like Apple’s iCloud, Microsoft’s OneDrive, Google Drive and Dropbox where saving to a local folder automatically generates a remote copy. But don’t forget your own local copy on portable media. Ultimately the Internet is run by businesses and businesses have been known to shut off services. So remember your three golden backups for all your content.
HTML Menu Bar Which Switches to Dropdown for Mobile
For a web site to be successful it must tick several boxes. It needs an attractive design, great content, no pop-ups, not throw to many advertisements at visitors and work well on a variety of screen sizes. The last point is important as mobile devices are now the dominant platform for accessing the web. Achieving multi-screen support from a single web site saves time (no need to update the design more than once). Time is a precious resource for most people and businesses.
A web site needs to respond to the device it is being viewed on, hence the term responsive design. When a website uses a menu to allow the viewer to jump to other pages, that menu should work well on different screen sizes. This article is a responsive menu tutorial giving an example implementation of the Responsive Nav plugin. This provides a basic responsive web site menu without using any other frameworks or libraries. As the screen shrinks the menu switches from traditional horizontal to a button. The button is used to dropdown the menu on smaller screens. Continue reading
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.
PHP 5.3 to 5.6 Upgrade for CentOS Using External Repos
CentOS Linux is often an option when configuring a Virtual Private Server (VPS). CentOS is designed for stability, being based upon Red Hat Enterprise Linux (RHEL). This means that although it has a long shelf life it may not have the latest features available to the Linux community. To help overcome this other repositories can be used to update the CentOS installation. Here is a list of some alternative repos for CentOS that provided various updated packages:
One package that may require updating is PHP. CentOS 6 will be supported until 2020 but comes with PHP 5.3, a few point releases behind the current PHP version. In this article the PHP available in CentOS 6 is updated to a later version. This tutorial is based upon a VPS running a minimal installation of the latest version of CentOS 6, the 64 bit version. The tutorial was tested on a Virtual Machine (VM) duplicate of the VPS on a local machine to ensure that the configuration steps correctly worked before applying the upgrade to live environment. Always have a backup of live data and always test upgrades on a duplicate test system. This minimises the risk to a live system.
It is assumed that the VPS is accessed via a Secure Shell (SSH). This method of access can be duplicated on a local test environment to replicate the real world set up. To upgrade PHP log in to the VPS and install an alternative repo, then use yum to install the later PHP version. Here repositories from Les RPM de Remi is used. Continue reading
Tutorial to Upload and Extract a Zip File from Windows to a CentOS VPS
On Linux files are normally compressed individually to create a .gzip version using the gzip utility. Or several files are collected into a Tape Archive, .tar, which is an uncompressed collection of files created using the tar utility. A .tar is then compressed to a .gzip to create a .tar.gz. In Windows files are normally zipped, which is a format that collects and compresses several files into a single .zip file in a single operation.
When managing a Linux based Virtual Private Server (VPS) or other remote Linux machine, such as a web server, there can be occasions when a zip file created on Windows needs to be extracted and managed on the remote Linux machine. This can be done with the Linux zip (to compress) and unzip (to extract) utilities.
Install Zip and Unzip onto CentOS
A VPS may not run a full blown Linux, for example a CentOS VPS may run the minimal CentOS installation for efficiency. In which case the zip and unzip utilities may not be installed. These utilities can be installed on CentOS using yum:
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
Create a Free Website Online Using WebMatrix, Azure and Microsoft Windows
If you have a Windows laptop or desktop computer you can get started with website development with free Microsoft tools. One of several free software tools that Microsoft provides is WebMatrix. This contains a HTML editor in an Integrated Development Environment (IDE) and the express version of Internet Information Server (IIS) (a web server used for testing your website). A Windows PC running WebMatrix allows you to develop a website and publish it online for free using Microsoft Azure cloud hosting. Microsoft free hosting is for a small number of low volume websites. If the website is successful and generates high traffic it can be upgraded to a registered domain and paid for high volume Azure hosting.
This tutorial was based upon using a Windows 8.1 PC but Windows 7 can run WebMatrix. You will need an Internet connection and a Microsoft account to install and run WebMatrix and to use Microsoft Azure. Continue reading
CentOS 7 Supports In-Place Upgrading from CentOS 6.x for 64-bit Versions
This article covers upgrading a minimal CentOS 6.x system to CentOS 7. CentOS is a popular GNU/Linux OS for servers (including web servers) and workstations. Popular because it is a community based version of RHEL. CentOS is often an OS option when purchasing and setting up a VPS. The current major version of CentOS is version 7. CentOS 7 can be installed via an in-place upgrade over CentOS 6. However, CentOS 7 is only a 64-bit OS and therefore the system being upgraded has to be running 64-bit CentOS 6.
NOTE: This article is for archived information purposes only. According to the CentOS Upgrade Tool web page, the tool is currently broken.
To check if CentOS is 64-bit or 32-bit use the uname command with the -p option (p for processor):
[root@servername ~]# uname -p
The 64-bit CentOS will display x86_64 and 32-bit will display i686.
Words of caution. If your system has been highly customised then performing an in-place upgrade from CentOS 6 to 7 may not be successful. In this case, as for upgrading a 32-bit system, a data backup, new CentOS 7 installation and data restore will be required. Do you need CentOS 7 now? There is also no need to rush to upgrade to CentOS 7. CentOS 6 will be receiving updates until the end of 2020. This article is for informational and test purposes only. You are responsible for you own actions and an in-place upgrade from CentOS 6 to CentOS 7 is probably more trouble than doing a fresh CentOS 7 install and data restore. For example upgrading a minimal CentOS 6.6. to CentOS 7 may not work according to this bug report.
The other consideration is whether the new CentOS 7 features will hinder operation of your system. The new features may require changes to the normal workflow or they may be incompatible with software that is being used on the system. Whilst the CentOS 7 Release Notes list some major changes the RHEL 7 Release Notes has a detailed discussion. Continue reading