Yep, another series of software updates have been called for, and Shodonix 1.04 is already out. We’re working on a new initial boot splash image, but otherwise, the CD is ready for workshop use.
My supervisor pointed out last week that “I bet you didn’t think you’d be maintaining a Linux distro when you started”, and he was right. Far from the initial idea I had to just stick all the requested tools on a CD (in Mac and Windows formats), and then bring the CD but run stuff from it using existing machines, the project morphed into “let’s customize a Knoppix iso”, and then into “let’s make this really cool, with custom graphics, lots of extra tools, and… oh yeah: document it so that we can continue to maintain it in the future”.
Nope, I hadn’t planned on maintaining a Linux distro when I started here, nor even when I started back this summer. Strange how things go sometimes. Admittedly, the distro is just to be used in-house, but it’s still pretty cool, and I can now do it for anyone that needs/wants a customized CD.
Posted by wmyers as projects, personal at 2:05 PM EDT
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I have been programming for several years, and have been exposed to all sorts of problems along the way. However, Friday was about my first opportunity to actually use a tree traversal in a ‘real’ project, not just one assigned by a professor.
As most *nix types are aware, you can set up an aliases file to map addresses onto real world users. The problem with this file is that aliases can get stale, new aliases can be made that end up totally encompassing old ones (unintentionally), etc.
So, the request came about to be able to use a webform to look up where, exactly, an alias points. So, into our work order ticketing system it went, and I started working on it on paper Thursday evening. Turns out that it is not in fact to be a graph problem but rather a tree problem. This is a Good Thing™. Graph problems aren’t horrible to work with, but they are substantially more complex than tree problems.
The general form of the /etc/aliases file is listed above, but I left out an important caveat - aliases can point to a file of delimited targets via the :include: directive. To make a medium-length story pretty short, to parse the aliases file, every line needs to be read, and then tokenized to display the results of a search, recursively.
I suppose you could traverse the tree using a loop-based approach, but heaven help you to handle the corner cases. The only I have to track in traversing the tree is what the most recently checked alias was, and advance to the next one in the list when the check on that iteration is over.
Overall, it turned out to be a really easy to write script, and it’s now live on our site. If you are Shodor staff, you can play with it here.
Posted by wmyers as work at 4:29 PM EDT
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If you ever need to get the name of the page you are on, and you don’t need the path, this will do it for you:
ltrim((str_replace(dirname($_SERVER['PHP_SELF']),"",$_SERVER['PHP_SELF'])),"/\\");
Posted by wmyers as hints at 11:20 AM EDT
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one package was missing, and another was acting up, so the image has been recreated again
we should be one user test away from using the cd in workshops
Posted by wmyers as work, projects at 11:19 AM EDT
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The image has been shrunken enough to fit under 700M (694.7M to be axact). Now the CD is going through testing before being deployed to offsite workshops.
Posted by wmyers as Uncategorized at 1:41 PM EDT
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Right. So, it turns out that if you don’t unmount /proc while chrooted, the iso won’t compress properly, which is what happened to my first attempt. The second following attempt was done from a fresh expansion of Knoppix, and I made sure I unmounted /proc, and everything’s copasetic.
The last thing to get working is the offline edition of Interactivate to load correctly (and fit). I am currently 10M over the limit, and the launch shortcut is wrong, but we’re very close.
Posted by wmyers as news, work, projects at 6:10 PM EDT
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the first edition of our custom cd is ready - now to test 
Posted by wmyers as news, work, projects at 1:52 PM EDT
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This is an odd one: I’ve managed to grow my custom linux image from 1.8 to 2.1 gigs, yet it compressed to 657M as an iso. Queer. Now the problem is that I’ve apparently gotten a little too aggressive in trimming, and I can’t log in when it boots.
Posted by wmyers as work, projects at 3:03 PM EDT
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even after shrinking our custom linux/cd install down from the default knoppix size of 2.3G to 1.8G - it won’t compress to fit on a single cd, which leads me to believe that what I’ve stuck on there is already compressed
back to trimming-out unnecessary items 
Posted by wmyers as work, projects at 1:25 PM EDT
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at first, this appears to be a task that’s harder than it’s worth, but it’s not
after several passes through the installed packages that come with knoppix list, I believe I’ve trimmed out everything we don’t need to provide a mobile lab environment
Posted by wmyers as work, projects at 3:15 PM EDT
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