Results tagged “linux”

retired radiators
The PDF spec includes an option to cause PDFs to open full screen when users open them. I’m a fan of the feature because it maximizes screen real estate and creates a simple, focused, experience for the PDF readers. Using this option is one of my two essential tips for creating an impactful newsletter targeted at being read online. The other tip is to use a “portrait” format document, to match the shape of most screens.

Many PDF viewers respond to PDFs that are set to open full screen, but a number of PDF generation tools don’t provide you option to set this preference when creating PDFs. I ran into this with Xournal which is a nice application for Linux-based tablets, but offers no PDF export options.

So I found a way to update a pre-existing PDF to set the preference to have it open full screen by default. The key here is that PDF is a text-based format, so preferences in it can be updated manually by opening and editing the file according to the PDF spec, or the same effect can be accomplished with automated tools. In this case, I found that I needed to update a line that started like this:

<< /Type /Catalog

After /Catalog, this is all that needed to be added:

/PageMode /FullScreen

I automated this with a simple script that I named make-pdf-full-screen.sh. It works for the simple case when no “PageMode” has been declared, as in the Xournal case. I don’t expect it would update the PageMode properly if it was already declared. For a safer solution consider opening the PDF in a text editor to manually set “/PageMode /Fullscreen” on the initial /Catalog line. Alternatively, you could use a formal solution like PDF::API3::Compat::API2 which appears to have the features needed to solve this with Perl.

Here’s the contents of my little script to automate the update:

#!/bin/sh
# usage: make-pdf-full-screen.sh file.pdf
#   The file will be modified in place so that it opens full screen.
#   The current approach is naive... it assumes no Initial View has been defined.
# by Mark Stosberg
perl -pi -e 's?<< /Type /Catalog?<< /Type /Catalog /PageMode /FullScreen?' $1
computer hardware co-op launches
Richmond High School student Jonathan Ulrich helped to set up and test a thin client lab.

This is an open letter to the Richmond, Indiana Community School system. There is a school board meeting coming up to discuss how to fund technology upgrades with a dwindling budget. I strongly suggest the school system consider Linux thin client labs as part of the solution. Thin client labs are made with low-cost, low-power, low-maintenance stations and have many advantages.

A Linux thin client lab is already being used successfully in the area. Four years ago in Brookville, Indiana a thirty-seat thin client lab was set up at St. Michael’s School. Initial costs were kept low through low hardware requirements and the use of free, open source software. The lab is still in use four years later. Minimal maintenance has been required, including zero virus/spyware/malware infections due to the use of Linux.

Thin clients don’t need a hard drive, which are at the top of the list of the common parts to fail in a computer. Instead, every workstation pulls all the software it needs from a single server, meaning there is a one computer to maintain software on in the lab, not thirty. So St. Michael’s unplugged the hard drives in their machines, cutting down on noise in the lab, and well as reducing the energy consumed by the lab.

I recommend checking for yourself on this success story. For the administrator perspective, contact the Principal, Ken Saxon at (765) 647-4961. For the IT perspective, contact Mike Heins, who set up the system and maintains it: (765) 328 4479, (also at mikeh@perusion.net).

The use of Linux in Indiana schools is not new, either. In 2005 the state of Indiana launched a state-wide initiative to put Linux on the the desktop of 300,000 Indiana high school students. Locally, Northeastern High School has made significant use of Linux.

I’ve already hinted that thin clients have lower power requirements and can be lower maintenance. The hardware needed for thin client workstations is not special. In fact, old desktop hardware that would otherwise be discarded for being slow is ideal. In a thin client system, the performance is determined by the server, and the workstation needs just a minimal amount of resources to connect to it.

With these principles, I built a four-seat demonstration lab at my church, using three computers so old that a local computer store gave them to me. I paid only $50 for a memory upgrade for the server. As a thin client lab, these old computers came back to life and performed like modern desktops, although they ran Windows 98 in their former lives.

Because a school lab setting is ideal place to deploy a thin client network, there are several projects that focus on exactly this, and give away the required software. These include K12Linux and Edubuntu. Both are exceptionally easy to try out and install, from personal experience.

Pursuing thin client now is a strategic move that works towards the goal of the City’s Comprehensive Plan to be a “Sustainable City”. The plan is fiscally conservative and technologically advanced, with low impact on the environment and energy bills.

new phone, ZN5 When trying to install some signed applications like Opera Mini on the ZN5
I get "root certificate missing", and the application fails to install.

This message refers a certificate that is used to confirm that the application is from a legitimate author. Based on confirmation of a legimate author, the
signed application then has the possibility of being allowed to some more
security-sensitive operations, such as reading and reading files that the
application did not correct.

For background on this issue, I recommend this post on Midlet signing on the Javia blog, and the post How MIDlet Signing is Killing J2ME.

My town runs Linux

re-using and recycling with the bakfiets Many of the key organizations I deal with in my daily life now run Linux on the desktop. First, let’s taken as given that I run it home and work and my wife runs it, too. Many other organizations in Richmond, Indiana have switched over to Linux on the desktop as well:

  • My church has three computers, one for the pastor, one for the office manager and one for the hardware recycling program. They all independently chose to run Linux. It’s a popular choice in the congregation as well, as with more than a dozen systems in use by members ranging from 4 years old past 64 years old.
  • My doctor, Kurt Ritchie, runs his business exclusively on Linux
  • My lawyer, Thomas Kemp, runs his law practice primary on a Linux-based groupware solution now, and travels with a Linux laptop
  • My grocery store, The Clear Creek Coop, runs exclusively Linux on the desktop. They bought a Dell laptop with Ubuntu pre-installed.
  • My bike shop, Ike’s Bikes, now runs exclusively Linux on the desktop.
  • A local high school, North Eastern, runs primary Linux on the desktop, as part of trend of over 20,000 Indiana students running Linux.
  • A local college, Earlham, features Linux labs
  • Local graduate schools, Earlham School of Religion and Bethany Seminary, also use and promote Linux on the desktop
  • A local computer store, System Solutions, has had a stack of Linux install disks to give out, and pledges interest to support Linux more in the future, citing frustrations with Windows Vista and Windows malware problems in general.

Those are the commercial desktop Linux desktop uses I can think of off the top of my head. Among home users, I’ve found that a number of people are installing Linux themselves now, from farmers to bloggers.

Microsoft may still have majority share on the desktop here, but in my world they are losing ground fast to the benefits of open source software.

Who has switched in your world?

Here's how I processed some digital camera videos for uploading to Flickr. The things I wanted to adjust were:

  • Shortening the length
  • Removing the original Audio track
  • Adding new music, using a sound loop

Nothing particularly that seems like it should be hard. (Details after the break)

First, I found a sound loop from SoundSnap.com.

By installing Audacity and using "Effect: Repeat", I was easily able to make the sound loop repeat enough times to cover the video.

Next, I stripped out the original audio using ffmpeg, while converting the file to the the MPEG format, and preserving the quality:


ffmpeg -i MVI_3876.AVI -an -sameq out.mpg

Finally, I added in my new music, while also truncating the video to be 16 seconds:


ffmpeg -i out.mpg -i my.mp3 -sameq -t 16 final.mpg

While I would happy to know about graphical ways to accomplish what ffmpeg was doing, it wasn't particularly hard to read the documentation for ffmpeg and come up with these commands.

mobile bike mechanic, rear view

This was written for the Ubuntu release code named Feisty Fawn, but may apply to later releases as well.

Ubuntu is a great operating system, and I've already helped install it on a number of systems. Here are five customizations I make right away to make it a more pleasant system to suit my taste:

  1. Install the Flash and Java plugins. Ubuntu already has packages for these, but I believe they turned on by default for licensing reasons. Go to Applications: Add & Remove Applications and search for "ubuntu-restricted-extras". This will install Flash and Java plugins, as well MP3 support and some nice free Microsoft fonts. Check the boxes next to the listing and click "Apply" to finish the job. The Java plugin installs some things into the menu system that I think I'll never use, so I remove the entries for them. To edit the menu, right-click on "Applications" and select "Edit Menu". The menu editor should be fairly intuitive, and allowing you to remove "Java Web Start" and anything else you want. (Note: removing the menu items doesn't un-install these applications).
  2. Turn off Google Suggest. I find the "Google Suggest" feature in Firefox to be annoying. To turn it off, enter about:config in the Location bar and press enter. In the resulting interface that comes up, search for "suggest". The preference for disabling this feature will be displayed. Right click on "true" and select "Toggle". That's it!
  3. Enter fewer passwords. The following tips make the computer less security, but more convenient. Perhaps this trade-off isn't for you. First, you can skip the initial password screen at a boot and go straight to a particular account. To enable Auto-login of a user, go to System: Administration: Login Window: Security. Check the box for Enable Automatic Login and select a user to login automatically. On laptops, I also like to turn off the default of having a password appear automatically when the computer is resumed. To do that, launch the preference editor with Alt-F2 and then gconf-editor in the Run box. Once this program launches navigation to apps / gnome-power-manager. Check the box next to lock_use_screensaver_settings. Now this password will be disabled whenever the password for the screensavers are disabled.
  4. Play DVDs. Ubuntu can't play some encrypted DVDs by default due to legal restrictions in some countries. Go ahead and try to play a DVD. It will pleasantly notice that you don't have the all the codecs you need installed, and offer to install some helper software for you. However, for an encrypted DVD, this still won't be enough. After checking any possible legal restrictions that may apply to your area, you can run a simple command to install support for playing encrypted DVDs. Use Alt-F2 to open the Run box. Copy and paste this into the box: sudo /usr/share/doc/libdvdread3/install-css.sh. Be sure to check the "Run in Terminal" box and then press OK. You'll need to enter your administrator password, and then wait briefly for the installation process to complete.
  5. Use F-Spot for importing digital photos. I think F-Spot is a nicer photo manager than the default gThumbs application. F-spot comes installed by default is easy to set to have it open to import your photos when you plug in a digital camera. Go to System: Preferences: Removable Drives and Media: Cameras. The importing command you need to enter is: f-spot-import %h.

As part of my switch from Mandriva Linux to Ubuntu Linux, I had the opportunity today to contribute some improvements back to both operating systems.

Having just used Mandriva on this laptop, I knew it was possible for the sound to keep working after a suspend/resume cycle, but it quit working after the Ubuntu switch.

Since Mandriva's solution was made available under an open source license, I was able to review it adapt to work with Ubuntu, and Ubuntu can easily and legally accept this solution, if they choose.

Glabels Screenshot

Glabels 2 is an an excellent, free, open source Linux program for creating labels and business cards.

It was a snap to use it to create business cards. Without having used the software before, I was able to create what I wanted in just a few minutes. Not only does Glabels provide tools to design labels, it has built-in templates for hundreds of standard label-type designs, such as the business card sheets you can buy for home label printing.

coming home from dinner

My current favorite browser is Firefox. It's easy to use for novice web users, while housing advanced features that demanding folks will appreciate as well.

Firefox launches quickly. This is a basic but important quality. The larger Mozilla suite that Firefox is descended from does not have this trait.

The Ritchie family had a classic computer problem to solve. They had a used digital camera which didn't "just work" with either Linux or Windows in their home. The photos from the camera showed up on both, but didn't download properly on either.

They needed help from a geek.

After an afternoon of conversation and pie, the camera was working flawlessly with Linux, and no better on Windows. Here's why.

dale flips

I'd seen Windows XP from a distance, but I hadn't really visited until last night. Sure, I'd been a tourist, browsing on a Internet Explorer to see how it rendered, but I'd never stayed long enough to have a meaningful experience, like installing a new applications for myself, or trying to get a new piece of hardware to work with it.

So last night I had the chance to visit the land of Windows XP, helping setup a laptop to be more functional and secure. There were some pleasant sights to see: XP has a bit of eye-candy built-in, with dropshows here and there, and menus that fade in and out.

Soon I saw the signs that as a resident of Linuxland, I was in a different culture. It's a bit like having visited Europe and noticing the that cars are smaller, the washing machines are smaller and by golly, some of the beaches are really different.

So was my experience with Windows XP.

couch by bike

Over the weekend I continued my exploration of Linux thin clients.

Now that I had a proof-on-concept system working, I spent my computer time using the thin client, to see if there was anything to observe from "real life" use.

The performance was perfect. I could not perceive any lag time compared to sitting directly at my server computer.

The memory usage was also impressively low. I ran a second KDE desktop on the server, and the system reported "42% memory free", and I have only 256 Megs of memory!

Sharing the 700 Mhz CPU also seemed to be no problem. I could launch an application on the server, switch to the client and continue to work without a slow down.

With a server with "real" specs, I could see how a single machine could comfortably run a whole lab of computers.

Finally, I decided to compare the boot times of the server and the thin client.

The server took 3 minutes to boot to the graphical login screen, while the thin client took only one minute. Another win for thin client users!

I also appreciated the absolute silence of my thin client. There was no hard drive to whir in the pizza-box sized machine, and no fan to run because of the lower power and processor requirements. A totally quiet computer was easy to adjust to!

Challenges

Kurt wanted a Linux solution his whole family could use, including his wife and two pre-teen children.

His wife Amy was used to using WordPerfect and preferred it. For the children, it was important to have games on the system, especially "The Sims".

Also, they had been using Juno for their ISP, and wanted to keep it to preserve their e-mail address as well, as well as continue taking advantage of that low cost service.

Morphine Explosion Today I tried to scan something using Linux for the first time. Although must hardware I want Linux to talk to general works well, I still have a number of memories of finesses and fussing with things to get them to work (moreso from the distant past than recently). This is what I expected out my first Linux scanning experience.

Instead, It was an very impressive experience. I plugged the scanner in and it was recognized. I easily found and installed a scanner package called Xsane using Mandrake's built-in Software Installer. (I just searched for software with 'scanner' in the description').

XSane needed no configuration to talk to my scanner. From my experience using Macs with various scanner, I recall that usually each scanner has it it's own specific drivers to install and software to use, often with mediocre features and inteface.

I needed to install no additional drivers in this case.

Although XSane was feature rich, it was easy to find just the details I needed to adjust the colors, rotate and crop the image, and save it in a file format of my choice.

I would say that XSane is the best scanner interface software I've used so far.

With Kprinter, it was easy to complete my task by turning the 7 PostScripts I had generated into a single PDF. I simply needed to open the files in Kprinter, and then choose the "Save to PDF" option.

It was a pleasant first experience to discover this Linux desktop software that was not just "good enough", but excellent.

I look forward to more "Just Works" experiences.
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