Ryan, Debi, and Toren Cragun's Blog

While I’m a major geek and I love technology, I’m also cheap.  Ergo, we’ve had the same cell phones for three years: HTC 8125s.  They’ve been good phones, but they ran a very outdated Windows Mobile operating system with limited functionality.  I eventually convinced Debi that it was time to upgrade to new smart/app phones (to pay the difference in our monthly bill we dropped cable, which isn’t a big deal since we rarely watch TV these days anyway).  As Linux users, we obviously were not interested in buying phones with the new Windows 7 Mobile operating system on it.  We also didn’t want iPhones, which would force us to run Windows or Mac OSX in order to get iTunes.  And, I’ve been hearing great things about Android (which is now more widespread than the iPhone in the cell market), so we went with the new Verizon Droid Incredible Android phone:

Droid Incredible

The specs are pretty impressive, but really I’m just very, very impressed with the basic functionality of the operating system and phone.  Phone operating systems have come a long way since we bought our HTC 8125s with Windows Mobile 5.  It’s quite literally a smart phone as the following feature illustrates: the screen goes blank when you put the phone up to your ear to talk and comes back on when you pull it away from your ear.  That simple feature is genius for two reasons: (1) You can’t push any buttons with your face when you’re talking, which Debi loves, and  (2) you don’t have to hit a button to bring the screen back up to hang up when you’re done as it automatically comes back up for you (our old phones had both of these problems).  Genius.  Google Maps and Navigation are super slick – so long dedicated GPS.  You can pull up Google Maps, search for something, find it, then click on it and select navigate and the phone instantly converts into a GPS unit with audio directions that include street names.  Also, the map is scrollable while you navigate.  It’s super slick!  Of course, there are lots of apps, but I find that I don’t really use most of the apps, just some of the basic stuff – like Gmail, Google Reader, the internet, and Google Maps.  Oh, and the phone integrates perfectly with your Google Contacts and Calendar, making it super easy to schedule appointments and update contact information on the go.  You can also use Google Chat on the phone as well, which is even better than text messaging for instant communication (Debi and I have used it already).  Oh, and if you have a Google Voice account (which I do), the integration is superb!  It manages all of your voice and text messages in a fashion that is really quite remarkable.

I was a little wary about the lack of a slide out keyboard, but once I found out that the phone has the ability to transcribe voice (and it’s pretty reliable), I figured it was unnecessary.  Plus, the horizontal on-screen keyboard is just as good as a slide out keyboard as far as I’m concerned.  So, at this point, I don’t have any complaints.  It’s a remarkably slick, sleek, useful device.  Oh, and as an added bonus, there is a free Tricorder app for Android that actually works, generating pretty interesting information, including compass directions, wireless networks, signal strengths, and solar activity:

Tricorder App for Android

Now I can walk around with my phone and say, “Let me check my Tricorder.”  Geek heaven!

Thanks to a little surplus grant money, I was able to purchase a nice, large, external monitor for my office.  With my docking station, that meant I could use two monitors simultaneously – my laptop monitor and my external monitor.  I had been doing this previously, but the external monitor I had before was about the same size as my laptop monitor (15″), so setting it up using dual monitors in Ubuntu was relatively easy.  But the new monitor is, well, huge (28″) and has a much higher native resolution – 1920×1200 vs. 1024×768.  I had two problems when initially trying to set up my new dual monitor system.  First, X11 wasn’t correctly detecting the possible resolutions for the monitor – it only allowed resolutions up to 1024×768.  Second, X11, when I first set up the dual monitor system, created a default virtual monitor that was 2048×768, which basically meant that I couldn’t go any larger than that.  As it turns out, solving the second problem solved the first problem for me.  Keep in mind that I’m using Ubuntu 9.04 on my laptop because of some other X11 problems that 9.10 had when I first tried it out.

Here’s how I solved this.  In a terminal, I input the command to modify the X11 configuration file:

$ sudo gedit /etc/X11/xorg.conf

Technically you should always back this up before you mess with it, but I didn’t this time around as I knew I was just going to change one thing and figured I could always change it back if there was a problem.

In the “screen” section of the xorg.conf file, it said:

Section “Screen”
Identifier    ”Default Screen”
Monitor        ”Configured Monitor”
Device        ”Configured Video Device”
SubSection “Display”
Virtual    2048 768
EndSubSection
EndSection

I changed the settings for “virtual” to: 2944 1200, which is the maximum width and height of my new monitor combined with my laptop monitor (width – 1920+1024=2944; height – 1200 encompasses 768, so I went with 1200).  So my new xorg.conf file looked like this:

Section “Screen”
Identifier    ”Default Screen”
Monitor        ”Configured Monitor”
Device        ”Configured Video Device”
SubSection “Display”
Virtual    2944 1200
EndSubSection
EndSection

Once I changed this, I logged out, then logged back in.  Then using the “Display” tool (System->Preferences->Display), I selected my 28″ monitor and found that the maximum resolutions were now available.  I chose the correct one – 1920×1200, and hit apply.  Et voila, my dual monitors are now using their maximum resolution.  I think the video card in my laptop is freaking out trying to handle this resolution, but it works!

On Windows, I used the free program Eraser to wipe hard drives when I was finished with them. I looked for a while for something similar for Ubuntu Linux but couldn’t find any programs like Eraser.  Turns out, however, that this functionality is built into the operating system, though it is command-line only.  Here’s an example of the command with an explanation following:

# shred -vfz -n 100 /dev/hda

Here’s what this does.  The # sign is the command prompt.  “shred” is the command that tells the operating system that you want to not only erase all the files on the drive but also to over-write those files with random bits.  The “f” in the “-vfz” command forces the write by changing the permissions on the drive wherever necessary.  The “z” in the “-vfz” command writes zeros to the drive.  The “-n” command is followed by a number (“100″ in the example above).  This tells the operating system how many times to write random data to the drive.  The more times you write over the data you had on the drive, the lower the odds that someone will be able to recover your files.  Writing over your data 100 times is likely overkill; 3 to 5 times is how many times I typically wrote over data using Eraser (which does the same thing).  Finally, the “/dev/hda” portion of the command tells the computer which drive to wipe.

If you are wiping your primary drive, you’ll need to boot into Ubuntu (or some other brand of Linux) using a live disc then open a terminal and type the above command.  Otherwise, the primary hard drive will be from where the operating system is running,which means you won’t be able to issue the command.  There is, apparently, a disc image you can download that makes wiping the primary drive quite easy: Darik’s Boot and Nuke or DBAN.  It’s basically like booting using the live disc, but the sole purpose of DBAN is to wipe the drive.

If you’re wiping an external drive, you just need to know the letter of the drive, and can then swap that out in the command (e.g., “/dev/hdc” or “/dev/hds”).  You can figure this out by looking in the “dev” folder or by using gparted.  Just make sure you get the right drive; you don’t want to try wiping your primary drive or any other important information.

For those reading this who don’t know why you would want to securely delete your files, here’s the rationale: just deleting files on a hard drive doesn’t mean someone can’t recover them.  I’ve recovered deleted files for students from their hard drives and from thumb drives numerous times; it just requires a little technical know-how.  This is much more difficult using EXT4, the Linux file system, but quite easy using NTFS, the default file system of Windows (or FAT32). But there are things you can do to pretty securely erase files from a hard drive.  What this program does is erase the files on the drive and overwrite that data with random data.  You would do this if you: (1) had files on your drive you deleted that you don’t want anyone else to be able to recover; or (2) you were giving away or selling your hard drive to someone else (e.g., on Ebay) and didn’t want them to have access to any of your files.  I did this to the hard drive of a laptop I recently sold on Ebay to ensure that they couldn’t recover my data.

Oh, and one more thing, the above instructions come from here.  I reposted them here with additional instructions so I’ll have it for future reference.

The Problem:

You have a spreadsheet that has a column of what you think are numbers in it.  The numbers display fine in their cells, but when you try to do something with them, you find that you can’t.  For example, you may want to sort them or use them as part of a calculation and it doesn’t work.  Here is a screenshot illustrating that the numbers look like numbers in their cells:

If you click on one of the cells, you’ll see that the numbers actually have a hidden apostrophe in front of them, like you see in this screenshot:

After spending some time on the internet, I finally found out what is going on.  While you think those are numbers, the apostrophe is Calc’s way of saying that the numbers you see are to be treated as text, but they are in a cell that is formatted as a “number.”  You can verify this by right-clicking on the cell, selecting “Format cells” and then clicking on the “Numbers” tab, as illustrated in the screenshots below:

So, the spreadsheet program is treating a series of number as text in a cell formatted as numbers.  Talk about aggravating.

The Solution:

There is a solution for this.  It involves a “find and replace” function.  From the “Edit” menu, choose “Find & Replace.”  In the “Find” box, type “^.” (i.e., carat + period).  In the “Replace” box, type “&” (without the quotes, of course).  But you have to do one more thing for this to work.  At the bottom of the “Find & Replace” window you’ll see a button that says “More Options.”   Click on it, then select the box next to “Regular Expressions.”  You should now have a “Find & Replace” box that looks like this:

Now, hit “Replace All” and all of your apostrophes will disappear.  Your series of numbers will now be seen as numbers by your spreadsheet program and will be in cells formatted as number cells.  Problem solved.

Notes:

I actually don’t know how/why this works, but it does.  I found the solution here.

I’m not a computer programmer (sometimes I wish I was), so I’m going to guess that implementing the ability to save handouts as PDFs in OpenOffice.org’s Impress (OpenOffice’s version of Powerpoint) may be a very challenging programming task.  For those who have never used OpenOffice, one of its greatest features is the built-in ability to save documents as PDFs.  You can save your slides in Impress as PDFs, but if you want to put multiple slides on one page with lines for notes for your students (which is what I do with my discussion notes), there isn’t a way to directly export those handouts as PDFs.  You can customize the handouts, which is a very nice feature, but you can’t save them to PDF.

However, there is a way to work around this limitation.  It’s actually quite simple, but it took me about 30 minutes to figure out.  So, here’s another Ubuntu how to.

First, you need to install a PDF printer in Ubuntu.  This is actually quite easy, though I recommend you do it from the command line as it is even easier this way.  So, pull up a terminal and type:

sudo apt-get install cups-pdf
mkdir ~/PDF
sudo chmod u+x,a+x,+s /usr/lib/cups/backend/cups-pdf
sudo /etc/init.d/cups restart

(I found the above here.)

What does the above do?  First, it installs the CUPS PDF printer.  Second, it makes a directory in your “home” directory called “PDF,” which is where the PDF printer will send your documents when they are printed.  Third, and this is the part that is difficult to do from anywhere other than the command line, it adds access to the CUPS PDF printer to your User.  If you don’t do that, you can’t access the printer.  The last line simply restarts the CUPS printer.

You now have done the hardest part.  The next part is simply to set up your handouts in OpenOffice Impress:

Once you’ve done that, go up to “File->Print”.  Choose the “PDF” printer.  Then choose “handout” in the middle of the window and how many slides you want per page:

When you’re ready, hit “OK”.  Now, go check the “PDF” folder in your “home” directory and you should see a PDF there with the handouts.  Voila!  You can now create PDFs of handouts in Impress.

Notes:

1) You can set the printer to print in color by clicking on the “Properties” tab.  It’s set to print in “grayscale” by default.

2) You can also set the PDF printer as the default printer in Ubuntu.  Go to “System->Administration->Printing.”  You should see the PDF printer.  Right-click it and set as default.

3) Microsoft’s Powerpoint can’t do this either.  You have to install a PDF printer in Microsoft’s Powerpoint to achieve the same effect.

4) I have received an error after doing this before.  Apparently there was a “security” issue in that the PDF printer didn’t have some rights to access files.  The error said “cups-insecure-filter.”  I fixed this using these directions:

Open a terminal and type the following:

sudo chown -hR root /usr/lib/cups/filter
sudo chown -hR root /usr/lib/cups/backend
sudo chgrp -hR root /usr/lib/cups/filter
sudo chgrp -hR root /usr/lib/cups/backend