Undo your Mistakes!

Sometimes we make mistakes.  Fortunately, sometimes we can undo our mistakes.   Undo is a command or option in many computer or phone programs that undoes the last change made,  reverting the data or program to its state before the change was made.

The opposite of undo is redo. The redo command undoes the last undo. Both undo and redo are available in almost all computer software today.

Below are some ways to undo some of your technology mistakes.

General Undo Functionality

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Free PDF Editors

PDF has become one of the most common file types, one that’s popular among businesses attempting to go "green" or "paperless", as well as popular for sharing documents on web sites.  Part of their popularity is that they, in theory,  cost nothing to produce and assure that documents will appear the same to anyone, anytime; anywhere. PDFs can also be interactive or contain forms, if desired; and they can be partially or completely edited by peers. As more people switch to using PDFs, the desire or need to easily create and edit them also grows; thus, having access to the best

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Free Options to Photoshop

Adobe Photoshop has long been one of the premier image-editing computer programs available. If you're a graphic designer, professional photographer, or illustrator, this is probably what you use.  But it isn't cheap, it doesn't run on all operating systems; and it probably includes more functionality than is needed for most hobbyists, scientists, or students, adding to its complexity. Fortunately, there are free options to Photoshop, including some that are easy to use.  Below, we review three of the most popular applications we've used. (We should mention that web-based

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Red Hat Satellite Service

Many Linux system administrators have been using CentOS (or other Red Hat variants) for years due to the historically high purchase and licensing costs associated with using Red Hat Enterprise Linux, or RHEL.

However, several years ago, UT set up a Red Hat Satellite system that allows UT personnel to use RHEL on their UT systems without cost for the base system and current patches.

Red Hat Satellite is an IT infrastructure management tool, primarily used to monitor and manage RHEL systems and environments.  While Red Hat Satellite can provide

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Passwordless SSH/SFTP Access in Linux

You can somewhat easily setup passwordless access to most Linux machines via ssh from a specific, trusted Linux machine (e.g., your office machine, laptop, etc).  To do so, follow these steps:

  1. On the bash shell of the machine and account you want to ssh/sftp FROM (e.g. your laptop), generate an ssh key pair if you don't already have one:

    if [ ! -d ~/.ssh ] ;
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Cleaning Your Personally-Managed Linux System Using BleachBit

Utilities exist to help you find and clean your system of old and unused files. This allows you to free up disk space.  In this article we will look at installing and running on personally-managed Linux systems a utility that's free and available not only for many Linux distributions, but also Windows and Mac OSX.

Before we begin, it is important to keep in mind that running utilities that delete files with elevated privileges can break a system. One must always exercise care when doing so. Always keep in mind when running BleachBit that its file deletions are

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Tutorial: Getting started with web development using Vagrant/VirtualBox

Due to the interest received towards development/programming, in this blog post we're going to take the time to detail how to get started with web development using a local virtual machine environment.  We'll also go over how to write a simple "Hello World" script in PHP.  

  • git installed on host machine
  • Install VirtualBox
  • Install Vagrant
  • Ensure VirutalBox + Vagrant are compatible.
  • PuTTY or some other SSH client (Windows only, native in Linux)
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How to Keep Linux from Hanging Up on You

When you run a command, in either the foreground or the background, on a Linux or Unix system and then either log out or get disconnected, the command you were running is normally killed.  However, there are ways to prevent this "hangup" situation from occurring.


The first and oldest method is to use the "nohup" (no hang up) command.   The "nohup" command instructs your process to ignore the SIGHUP signal that would normally shut it down at logout or when your session disconnects. This allows you to leave

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