Strings in Ruby

Watch out! This tutorial is over 4 years old. Please keep this in mind as some code snippets provided may no longer work or need modification to work on current systems.

Ruby has many ways of making strings, which are generally variations of the many ways Perl has of making strings. Double quotes allow values to be interpolated into the string, while single quotes do not. Most escapes are treated literally in single quotes, including the fact that \n is treated as two characters, a backward slash followed by an n.

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How To Set Up SSH Keys

Watch out! This tutorial is over 4 years old. Please keep this in mind as some code snippets provided may no longer work or need modification to work on current systems.

SSH keys provide a more secure way of logging into a virtual private server with SSH than using a password alone. While a password can eventually be cracked with a brute force attack, SSH keys are nearly impossible to decipher by brute force alone. Generating a key pair provides you with two long string of characters: a public and a private key. You can place the public key on any server, and then unlock it by connecting to it with a client that already has the private key. When the two match up, the system unlocks without the need for a password. You can increase security even more by protecting the private key with a passphrase.

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Manually Create a Sticky Floating Footer Bar in WordPress

Watch out! This tutorial is over 4 years old. Please keep this in mind as some code snippets provided may no longer work or need modification to work on current systems.

A sticky floating footer bar allows you to prominently display your important content to users. This bar remains visible to users at all time, so they are more likely to click on it and discover more useful content.

This method requires you to add code in your WordPress files, so we will be using the File Manager plugin, already installed on the DkIT WordPress servers.

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Introduction to Java

Watch out! This tutorial is over 4 years old. Please keep this in mind as some code snippets provided may no longer work or need modification to work on current systems.

JAVA was developed by Sun Microsystems Inc in 1991, later acquired by Oracle Corporation. It was conceived by James Gosling and Patrick Naughton. It is a simple programming language.  Writing, compiling and debugging a program is easy in java.  It helps to create modular programs and reusable code and is ‘platform independent’.

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Getting Started with the Computing Department WordPress Infrastructure

Watch out! This tutorial is over 4 years old. Please keep this in mind as some code snippets provided may no longer work or need modification to work on current systems.

The Department of Computing & Mathematics at DkIT has a very advanced WordPress Infrastructure for use by students in their class work and end of year projects.  We use a Viglen IX2300 (2 x Quad Core Xeon CPUs, 12 GB RAM, 2 x 146 GB SATA disks) for the primary web server, and two Viglen HX2220i units provide MySQL Database Replication, failover and load balancing services to the master web server. These servers are all powered by Debian Linux.

Also, traffic to the servers is cached at the college’s main reverse proxy server (regardless of source). The result is a very fast setup indeed!

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Using the WordPress functions.php file

Watch out! This tutorial is over 4 years old. Please keep this in mind as some code snippets provided may no longer work or need modification to work on current systems.

functions.php or the theme functions file is a template used by WordPress themes. It acts like a plugin and gets automatically loaded in both admin and front-end pages of a WordPress site. Usually this file is used to define functions, classes, actions and filters to be used by other templates in the theme. It can be used to add features and extend the functionality of both the theme, and the WordPress installation.

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Ruby Expressions

Watch out! This tutorial is over 4 years old. Please keep this in mind as some code snippets provided may no longer work or need modification to work on current systems.

This is the first in a series for beginners on the Ruby Programming Language. Note that Ruby is a programming language. Ruby on Rails (“RoR”) is a web-application framework that is implemented in Ruby. Do not confuse the two. We will not covering Ruby on Rails in these tutorials.

These tutorials will be gather together under the tag #RubyTuesday, as we will be posting one each week from today to the end of term.  Ready? Here we go

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Hello World in Morse code on Raspberry Pi

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Somebody posted a tutorial on YouTube showing a LED blinking”hello world” in Morse code using a Raspberry Pi.  However, they only show the code executing, not how it was put together. They also don’t show the hardware setup 🙁

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Port Scanner in Python

Watch out! This tutorial is over 4 years old. Please keep this in mind as some code snippets provided may no longer work or need modification to work on current systems.

This post will show how you can make a small and easy-to-use port scanner program written in Python. There are many ways of doing this with Python, but we’re going to do it using the built-in module Socket.

Do not run programs like this one against servers in the college. Behaviour like this could be seen as malicious and get you suspended!

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