Planet PLUG

Richard Freeman rich0

2010-09-04T16:58:36+00:00

Well, I spent half of today rebuilding my system, and upgrading mysql.

I figured that I might use the opportunity of my newly-found spare time while running revdep-rebuild to perhaps put out a general plea for developers to make use of the news feature in portage.

Upgrading to mysql 5.1 requires doing a full dump of your databases, some manual cleanup, an upgrade, and then some manual restore steps. Oh, and that dump has to be done BEFORE the upgrade or you end up having to revert back to 5.0 (which I ended up doing). Usually mysql upgrades are relatively painless, but jumps between major versions (0.1 level) are often not.

The upgrade also breaks anything that links to libmysql, which is quite a bit on a system that runs any number of services (mail, mythtv, ulog, etc).

It might have been nice if a news item were published a day or two before stabilizing mysql 5.1 so that users might have some advance warning and could plan accordingly.

Now, this upgrade didn’t rise to the level of some of the past breakages that actually were very painful to recover from and could result in unbootable systems/etc. Still, it never hurts to give users notice. The beauty of news items is that they only pester users who will actually be impacted by them. I don’t think anybody running mysql would mind a reminder that an upcoming upgrade requires careful planning – this is far more relevant to users than half the stuff we put in elogs/etc.

On the other hand, I do appreciate the mysql upgrade guide on the gentoo website (might not hurt to update it a tiny bit), and Peter Davies’s blog entry from 1.5 years ago was very helpful. If these had been pointed out before stabilizing the build the stable experience would have been a little smoother.

Filed under: gentoo

Alex Launi Gudev-sharp and GKeyfile-sharp have moved

2010-08-31T18:36:03+00:00

They’re now both hosted on github with the rest of Mono. Check it out! http://github.com/mono/gudev-sharp and http://github.com/mono/gkeyfile-sharp.

mjd A dummy generator for mock objects

2010-08-27T13:17:00+00:00

I am not sure how useful this actually is, but I after having used it once it was not yet obvious that it was a bad idea, so I am writing it up here.

Suppose you are debugging some method, say someMethod, which accepts as one of its arguments complicated, annoying objects $annoying that you either can't or don't want to instantiate. This might be because $annoying is very complicated, with many sub-objects to set up, or perhaps you simply don't know how to build $annoying and don't care to find out.

That is okay, because you can get someMethod to run without the full behavior of $annoying. Say for example someMethod calls $annoying->foo_manager->get_foo(...)->get_user_id. You don't understand or care about the details because for debugging someMethod it is enough to suppose that the end result is the user ID 3. You could supply a mock object, or several, that implement the various methods, but that requires some work up front.

Instead, use this canned Dummy class. Instead of instantiating a real $annoying (which is difficult) or using a bespoke mock object, use Dummy->new("annoying"):

        package Dummy;
        use Data::Dumper;
        $Data::Dumper::Terse = 1;
        our $METHOD;

        my @names = qw(bottle corncob euphonium octopus potato slide);
        my $NAME = "aaa";

        sub new {
          my ($class, $name) = @_;
          $name ||= $METHOD || shift(@names) || $NAME++;
          bless { N => $name } => $class;
        }

The call Dummy->new("annoying") will generate an ad-hoc mock object; whenever any method is called on this dummy object, the call will be caught by an AUTOLOAD that will prompt you for the return value you want it to produce:

        sub AUTOLOAD {
          my ($self, @args) = @_;
          my ($p, $m) = $AUTOLOAD =~ /(.*)::(.*)/;
          local $METHOD = $m;
          print STDERR "<< $_[0]{N}\->$m >>\n";
          print STDERR "Arguments: " . Dumper(\@args) . "\n";
          my $v;
          do {
            print STDERR "Value?  ";
            chomp($v = <STDIN>);
          } until eval "$v; 1";
          return(eval $v);
        }

        sub DESTROY { }

        1;

The prompt looks like this:

  << annoying->foo_manager >>
  Arguments: []
  Value?

If the returned value should be a sub-object, no problem: just put in new Dummy and it will make a new Dummy object named foo_manager, and the next prompt will be:

  << foo_manager->get_foo >>
  Arguments: ...
  ...
  Value?

Now you can put in new Dummy "(Fred's foo)" or whatever. Eventually it will ask you for a value for (Fred's foo)->id and you can have it return 4.

It's tempting to add caching, so that it won't ask you twice for the results of the same method call. But that would foreclose the option to have the call return different results twice. Better, I think, is for the user to cache the results themselves if they plan to use them again; there is nothing stopping the user from entering a value expression like $::val = ....

This may turn out to be one of those things that is mildly useful, but not useful enough to actually use; we'll see.

mjd Monad terminology problem

2010-08-26T15:37:00+00:00

I think one problem (of many) that beginners might have with Haskell monads is the confusing terminology. The word "monad" can refer to four related but different things:

The Monad typeclass itself.
When a type constructor T of kind ∗ → ∗ is an instance of Monad we say that T "is a monad". For example, "Tree is a monad"; "((→) a) is a monad". This is the only usage that is strictly corrrect.
Types resulting from the application of monadic type constructors (#2) are sometimes referred to as monads. For example, "[Integer] is a monad".
Individual values of monadic types (#3) are often referred to as monads. For example, the "All About Monads" tutorial says "A list is also a monad".

Usage #1 is not a real problem; it does not occur that often, and is readily distinguished by context, capitalization, type font, and other markers. #2 is actually correct, so there is no problem there. #3 seems to be an uncommon colloquialism.

The most serious problem here is #4, that people refer to individual values of monadic types as "monads". Even when they don't do this, they are hampered by the lack of a good term for it. As I know no good alternative has been proposed. People often say "monadic value" (I think), which is accurate, but something of a mouthful.

One thing I have discovered in my writing life is that the clarity of a confusing document can sometimes be improved merely by replacing a polysyllabic noun phrase with a monosyllable. For example, chapter 3 of Higher-Order Perl discussed the technique of memoizing a function by generating an anonymous replacement for it that maintains a cache and calls the real function on a cache miss. Early drafts were hard to understand, and improved greatly when I replaced the phrase "anonymous replacement function" with "stub". The Perl documentation was significantly improved merely by replacing "associative array" everywhere with "hash" and "funny punctuation character" with "sigil".

I think a monosyllabic replacement for "monadic value" would be a similar boon to discussion of monads, not just for beginners but for everyone else too. The drawback, of introducing yet another jargon term, would in this case be outweighed by the benefits. Jargon can obscure, but sometimes it can clarify.

The replacement word should be euphonious, clear but not overly specific, and not easily confused with similar jargon words. It would probably be good for it to begin with the letter "m". I suggest:

mote

So return takes a value and returns a mote. The >>= function similarly lifts a function on pure values to a function on motes; when the mote is a container one may think of >>= as applying the function to the values in the container. [] is a monad, so lists are motes. The expression on the right-hand side of a var ← expr in a do-block must have mote type; it binds the mote on the right to the name on the left, using the >>= operator.

I have been using this term privately for several months, and it has been a small but noticeable success. Writing and debugging monadic programs is easier because I have a simple name for the motes that the program manipulates, which I can use when I mumble to myself: "What is the type error here? Oh, commit should be returning a mote." And then I insert return in the right place.

I'm don't want to oversell the importance of this invention. But there is clearly a gap in the current terminology, and I think it is well-filled by "mote".

(While this article was in progress I discovered that What a Monad is not uses the nonceword "mobit". I still prefer "mote".)

yonkeltron Newschool Git workflow with Magit

2010-08-25T16:49:40+00:00

I’ve been on a roll with using Emacs to make my workflow more efficient. So far, so good. The latest major addition is my adoption of the most-excellent Magit mode for integrating Git and Emacs in a wonderfully-efficient way. One of the best features is that you get a magit-status buffer which acts like your Git command center. From there you can perform whatever actions you want and call up any repository information you need with ease. The feature I really wish it had was a git-blame viewer but Magit has so dramatically improved my git workflow that I really don’t care.

Alex Launi OMG that’s so 2009

2010-08-21T13:47:26+00:00

Yesterday it finally landed. Gabriel Burt, one of Banshee’s maintainers, merged in the GIO/udev hardware backend that Alan McGovern and I have been working on. This is awesome for everyone. Here’s why it’s awesome for you.

Are you a user?

More reliable device detection (maybe, we hope at least!)
More devices supported, including your iPhone or iPod touch!

Are you a distribution?

No more HAL dependency! You can finally actually drop HAL from your iso and ship the best media player Gnome has to offer (sorry Rhythmbox- we just rule really hard).

Want to check it out? Banshee 1.7.5 will be released on September 1, or you get get it now from Banshee git master. There are a few new dependencies you’ll need- here they are.

gio-sharp: git://gitorious.org/gio-sharp/mainline.git
libgpod-sharp: git://gtkpod.git.sourceforge.net/gitroot/gtkpod/libgpod
gudev-sharp: git://gitorious.org/gudev-sharp/gudev-sharp.git
gkeyfile-sharp: git://gitorious.org/gkeyfile-sharp/gkeyfile-sharp.git

I recommend building with the –disable-hal flag, that’s how you really get the creamy goodness of our work. Now go git r done! Please test, break, hack, and caress. We’ve tested with iPods, iPhones, Mtp devices, Android phones, and maybe some other crap, but I’m sure you have something weird we’ve never tried. We want it to work- nay- we need it to work. We get off on it working.

And here’s the screenshot you read all of that bullshit just to see…

mjd A short bibliography of probability monads

2010-08-18T18:03:00+00:00

Several people helpfully wrote to me to provide references to earlier work on probability distribution monads. Here is a summary:

Material related to Martin Erwig and Steve Kollmansberger's probability library:
- Probabilistic Functional Programming in Haskell, their 2006 paper
- the package, described in the paper, and specifically its probability distribution monad
- Some commentary on this library, by someone who doesn't put their name on their blog.
Some stuff from Dan Piponi's blog:
- "Monads, Vector Spaces and Quantum Mechanics, part I"
- and part II
Eric Kidd's blog: "What would a programming language look like if Bayes’ rule were as simple as an if statement?"

My thanks to Stephen Tetley, Gaal Yahas, and Luke Palmer for these.

I did not imagine that my idea was a new one. I arrived at it by thinking about List as a representation of non-deterministic computation. But if you think of it that way, the natural interpretation is that every list element represents an equally likely outcome, and so annotating the list elements with probabilities is the obvious next step. So the existence of the Erwig library was not a big surprise.

A little more surprising though, were the references in the Erwig paper. Specifically, the idea dates back to at least 1981; Erwig cites a paper that describes the probability monad in a pure-mathematics context.

Nobody responded to my taunting complaint about Haskell's failure to provide support a good monad of sets. It may be that this is because they all agree with me. (For example, the documentation of the Erwig package says "Unfortunately we cannot use a more efficient data structure because the key type must be of class Ord, but the Monad class does not allow constraints for result types.") But a number of years ago I said that the C++ macro processor blows goat dick. I would not have put it so strongly had I not naïvely believed that this was a universally-held opinion. But no, plenty of hapless C++ programmers wrote me indignant messages defending their macro system. So my being right is no guarantee that language partisans will not dispute with me, and the Haskell community's failure to do so in this case reflects well on them, I think.

Kam Salisbury Using Windows XP

2010-08-16T11:29:03+00:00

Set Compatibility Modes for Removable Media

*This post links to a published article and tests Search Engine Optimization (SOE) and other cloud Internet networking functions.

Tharun Kumar Allu TOra For Database Development

2010-08-05T18:05:15+00:00

TOra

TOra is an open-source multi-platform database management GUI that supports accessing most of the common database platforms in use, including Oracle, MySQL, and Postgres, as well as limited support for any target that can be accessed through Qt's ODBC support. TOra has been built for various Linux distributions, Mac OS X, MS Windows, and UNIX platforms.

Kam Salisbury Home Office All Done (finally)

2010-07-31T01:18:01+00:00

New Home Office all done! Complete with beer and light sabers. Big brown dog there when he feels like it.

Kam Salisbury Simple msmtp on cygwin

2010-07-29T02:58:47+00:00

Getting email out of your cygwin install and onto the Internet can be as easy as...

From the cygwin bash prompt, run msmtp-config to create a default msmtprc file in /etc/msmstp That msmtprc file is handy to copy into your cygwin home folder as .msmtprc
I use verizon so note the special port setting line I had to add to my .msmtprc file.
account default
host outgoing.verizon.net
from noone@kamsalisbury.com
auth login
user **********
password **********
port 587
*See http://www.scottro.net/qnd/qnd-gmail.html for hints on using tls or gmail as your smtp relay.
Depending on your specific needs you could create/edit a .mailrc file, maybe create soft links to connect scripts looking for sendmail to msmtp... I just use a variable in my scripts or input a litteral path such as...
echo "Testing 123..." | /usr/sbin/msmtp.exe mycellnumber@vtext.com
...and I get a text message once the long script is complete (example).

See? No exim or other MTA required.

Tharun Kumar Allu Set Up an Email Gateway with CentOS Linux�5.4 � Aaron Walrath – Another IT Guy's Meanderings

2010-07-28T16:35:19+00:00

A very useful mail gateway setup on Linux to be an edge server for MS Exchange.

Set Up an Email Gateway with CentOS Linux�5.4 � Aaron Walrath – Another IT Guy's Meanderings

Kyle Winfree 18 miles on 1 watt

2010-07-28T05:30:10+00:00

I finished a quarter wave dipole antenna yesterday, and had a chance to try it out tonight. I wasn’t able to get a signal report (I tested at 1am), but I definitely was able to get into several Philadelphia 440Mhz repeaters. This is neat to me because the antenna is so simple, yet already is showing better performance than a commercial mag mount antenna I have.

I made the antenna such that it can easily be taken apart. This way, it can be moved without the high probability that it would be damaged. Please see the pictures.

Kam Salisbury Yes, I am completing my Masters

2010-07-26T23:55:16+00:00

at Grantham University.

I go to class at times that fit my schedule (usually on the train to and from work).
I have a really diverse collection of classmates (some of the folks in my class are active duty military!)
I am always supported by the excellent teaching and administrative staff.

All the while holding a full time job, being a Dad, walker of the family dog and many other things. I recommend Grantham University as the "go to" destination for anyone needing a non-traditional classroom environment.

Alex Launi Anyone want to do a couple early morning pre-guadec rides?

2010-07-25T09:18:51+00:00

I know there are some other cyclists in the GNOME community who are probably bummed that they’re spending a week away from their bikes, so if anyone else is feeling withdraw symptoms from not riding I am planning to find a bike shop in Den Haag where I can rent a road bike and do some early morning rides before guadec starts. If you’re interested in some early morning pain and suffering grab me at guadec and let’s figure out a route.

Kam Salisbury New System OnLine

2010-07-22T04:23:25+00:00

SPACEE (the old Via C7 low power motherboard system) died with a blown capacitor recently so it was a great opportunity (excuse) to update my home office system.

After much searching I found several closeout Intel D510 motherboards on eBay. With more than one cpu core in a low power platform I was convinced it was the next motherboard for me! I also found two 2GB sticks of compatible RAM on eBay as well, the better to run 64bit with.

I chose a Chenbro server case (pictured) because it was roomy enough for almost anything I can upgrade to in the future.

The case has dedicated disk fans so keeping everything nice and cool should not be a problem. (Those dual 1TB SATA green Samsung drives used to be in a much smaller, warmer case.)

The mini-itx Intel Atom motherboard seems out of place in such a large case.
The picture does not show it well but I removed the stock 250w ATX power supply in favor of a 90w power supply from a smaller case. Even with that huge case fan I should still have ample power to spare.

Kam Salisbury Exim Authenticated Smarthost

2010-07-21T22:08:00+00:00

http://www.howtoforge.com/exim-authenticated-smarthost

Kam Salisbury Linux UFS

2010-07-21T21:45:53+00:00

You can mount almost any file system from the Linux command line (bash prompt).

Lets say you used to use the excellent Network Attached Storage solution, FreeNAS, which is based on FreeBSD. But now you are using Linux - how do you mount that FreeBSD partition (called slices in the BSD world) so you can copy the data over (because the Linux module for BSD type file systems is usually for Read Only use)?

Assuming you already have made a directory to mount the BSD type file system to and the BSD file system is on /dev/sda... sudo mount -t ufs -o ro,ufstype=ufs2 /dev/sda1 /mnt/bsd

If you make a syntax mistake typing in the command, be sure to read the command's error message carefully. Usually, the mount command itself will provide feedback similar to "...type dmesg for more information." Even more command usage information is available on most Linux systems from the command line via a command such as... man mount

Take your time, read though the command usage documentation and remember to copy - not move data, so you can always try a different strategy if the operation does not work out the way you had intended.

Kam Salisbury Fedora 13 Too Many Updates

2010-07-21T20:48:49+00:00

If you install Fedora 13 (64 bit) today (as I just did) you will see 400+ updates necessary to bring your system up to date. For the USB only folks that means 125+MB of updates in your overlay file. For the hard disk folks, updating installs the same amount but usually the hard disk folks don't care much because they have many more GB of room to spare.

The point = installing Fedora today (current release + several months) requires a larger amount of commitment than the early adopters. Respins (I love them) do not take care of the main distribution live CD release. My concern is growing that late adopters will be put off at an hour+ update path for the current Fedora Desktop. Can I help? Sure... can Fedora provide a Long term release support structure I can contribute to? I will wait and see.

Kam Salisbury B52 Freedom 1.0

2010-07-21T11:20:39+00:00

Downloaded over 300 times, B52 Freedom provides a green or cammo theme and background for the Windows Pocket PC and its later compatible versions. Click the image or this text to review and download...

Kam Salisbury Dell C400 tips

2010-07-21T03:37:23+00:00

Dell C400 Tips These tips assisted me whenever I had a need to rebuild the Linux Operating System on my Dell C400 laptop back in 2007. Suggestions I have here may work for other Dell laptops or other Linux distributions, experiment and share please.

The Dell C400 is a ultra mobile laptop platform sporting a Pentium III Processor, 1.2 GHz Mobile processor, touchpad/pointing stick and a 12.1 inch TFT Display. The C400 can be configured with up to two 512MB SDRAM DIMMs with a portion of that RAM supporting the Intel i830 series 1MB (shared) video. The C400 also has an internal 56k Modem, 10/100 Ethernet and sound card but all CD/DVD drives are externally connected via a special cable only. All hardware is detected by the Linux kernel (2.6.x) and modules with the internal modem requiring restricted drivers to be enabled. The latest BIOS revision does not support boot from USB devices, the single USB port being version 1.1 only. It is a great small format laptop with just a few quirks while running Linux.
Problem = Install halts (freezes) and no amount of intervention or cursing will allow the install to continue.
Cause = The install process fails to detect an appropriate setting for the frame buffer and the video display halts.
Fix = As with previous version of Ubuntu and other Debian based distributions, you will enjoy a smoother install if you chose a text mode install type, press F6 and delete quiet from the command line then add vga=773 acpi=on.
The install command argument vga=773 specifies an appropriate frame buffer setting so that the video display does not freeze when the hardware detection process probes for available video display resources. The install command argument acpi=on specifies that Linux should probe for and use the correctly identified applicable ACPI kernel modules for the C400's motherboard.

Problem = The install delays significantly for no apparent reason (You assume that the laptop is taunting you).
Cause = The hardware detection process will probe for a floppy disk drive (fd0) and will delay while waiting on the hardware query to time out.
Fix = Be patient, unless you hear motherboard beeps and more than 5 minutes of delay elapses, the laptop is not purposely trying to aggravate you. (It only seems that way)

Problem = X only sees 1MB of Video RAM. Cause = The default entry for the Video Chipset detected by Linux (Intel i830 series) during the install does not include a default RAM amount.
Fix = Edit xorg.conf to add video RAM amount.

Use the terminal shell to sudo nano /etc/X11/xorg.conf
Locate the following section of settings, add the lines shown if not already present...
Section "Device" Identifier "Intel Corporation 82830 CGC [Chipset Graphics Controller" Driver "intel" BusID "PCI:0:2:0"
VideoRam 16384
Option "DRI" "True"
Option "VBERestore" "True"
EndSection

*The VideoRam entry value must be a multiple of 1024. The Options DRI and VBERestore support the sleep and hibernate video functions.
Save your file edits (For nano it will be by pressing keys CTRL and X then answering Y for yes to save the file.
Reboot (Use normal shut down and restart options) to test.

Problem = Linux operating system start up and shut down display is absent or otherwise not viewable.
Cause = The default frame buffer video settings are not configured in grub for the type of LCD display on the laptop.
Fix = Edit Linux kernel grub boot parameters so that video (The splash screen during startup/shutdown) is shown.

Use the terminal shell to sudo nano /boot/grub/menu.lst
Move the cursor position to the end of the line that starts with # kopt=
add vga=773 acpi=on to the end of the line *Ensure there is a space separating the new entry from the text already present.
Save your file edits (For nano it will be by pressing keys CTRL and X then answering Y for yes to save the file).
Use the terminal shell to sudo update-grub
Reboot (Use normal shutdown and restart options) to test.

Problem = Linux does not suspend properly, sometimes runs the CPU full out instead of 1/2 speed to save battery.
Cause = APM instead of ACPI is installed by default, the tools to scale the CPU speed are not installed either.
Fix = Install the required tools and configure them.
*Warning! Test your changes. Make sure that no additional configuration changes are necessary to suspend to RAM when you close the laptop lid if that is your power saving intention. I'm not kidding, you could lose data because a setting change was missed here and all was assumed to be right as rain.

Use the terminal shell to sudo apt-get update *Errors in later process steps about not found packages means you did not enable various distribution repositories from the Synaptic sources configuration interface.
Then, use the terminal shell to sudo apt-get upgrade (Installing out of date packages is a waste of time and can actually cause conflicts requiring additional time to troubleshoot and fix later. Spend the time to have an up to date system now versus whishing you had done so... later.
Then, use the terminal shell to sudo apt-get install acpid cpudyn i8kutils
Reboot (Use normal shutdown and restart options) to test.

Problem = The Linux OS seems to spend a lot of time reading from the hard disk, even when launching often used or small applications.
Cause = Prelinking is not installed or configured by default.
Fix = Install and configure the prelink package, prelink does not actually boost performance of the entire OS, just loading of applications only.

Use the terminal shell to sudo apt-get install prelink
Then, use the terminal shell to sudo nano /etc/default/prelink and change PRELINKING= to yes
Save your file edits (For nano it will be by pressing keys CTRL and X then answering Y for yes to save the file).
You can start the initial prelink now by running from the Terminal shell. sudo /etc/cron.daily/prelink (The process will run for 30+ minutes in some cases) or just let cron do its job during the next reboot cycle.

Problem = There is 512MB of RAM installed and the Linux OS insists on heavy use of the swap file, slowing disk access considerably.
Cause = The default kernel setting for swap file use is not aggressive enough for high RAM installs.
Fix = Configure a more appropriate kernel swap directive.

Use the terminal shell to sudo nano /etc/sysctl.conf
add vm.swappiness=3 to the end of the file.
Save your file edits (For nano it will be by pressing keys CTRL and X then answering Y for yes to save the file).
Reboot (Use normal shutdown and restart options) to test.

Kam Salisbury silencio - a Dynamic Web Page

2010-07-21T03:22:46+00:00

Written in PHP, silencio dynamically builds a single web page that includes twitter.com posts. The code is open to customization with knowledge of HTML and CSS.

Kam Salisbury Rate My Network Diagram

2010-07-21T03:17:36+00:00

Reviewed over 2900 times, I remember scribbling this network diagram on an old Windows Pocket PC. Click the image or this text to review or upload your network diagram...

Kam Salisbury Server Farm 1.0

2010-07-21T03:15:05+00:00

Downloaded over 200 times, Server Farm provides a blue theme and background for the Windows Pocket PC and its later compatible versions. Click the image or this text to review and download...

Kam Salisbury Her Eye 1.0

2010-07-21T03:13:55+00:00

Downloaded over 600 times, Her Eye provides a blue theme and background for the Windows Pocket PC and its later compatible versions. Click the image or this text to review and download...

Kam Salisbury Hacking the WD My Book World Edition (WDWE)

2010-07-21T03:10:40+00:00

These tweaks are for the newer (2009+?) version of the Western Digital My Book World Edition (WDWE) with the white status bar on the front of the unit (pictured above). All of the tweaks listed on this page enable/disable features already built into the stock firmware or add additional capabilities via optware software packages. No part of the firmware is replaced so the likelihood of breaking this Network Attached Storage (NAS) unit is very low. Of course, you are the only person responsible for your specific NAS unit at all times - apply the tweaks on this page at your own risk. Be sure to update your NAS unit to the latest firmware. The firmware used (version 01.00.16) with the tweaks on this page is shown here. Disable the Remote Access (MioNet) if you do not actually intend to use it. This change will save you a some RAM and CPU horsepower that can be used to run other processes on the NAS unit. *Just un-check the "Enable MioNet on Startup" box as shown Disable NFS unless you have Linux (or another type of UNIX) computer on your network that will use this NAS unit for storage. Also, disable AFP if you do not have an Apple Computer in your house or on your network. Just like disabling MioNet in tweak #2, this change will save you some RAM and CPU horsepower that can be used to run other processes on the NAS unit. Enable SSH to access the WDWE's internal operating system. Remember how we saved some RAM and CPU horsepower tweaks #2 & 3, this changes uses some of that freed up horsepower. *Be sure to generate a new certificate or your SSH communication will not be encrypted Install optware support (login as root to the MBWE via ssh then enter the following commands one at a time) feed=http://ipkg.nslu2-linux.org/feeds/optware/cs05q1armel/cross/unstable ipk_name=$(wget -qO- $feed/Packages | awk '/^Filename: ipkg-opt/ {print $2}') wget $feed/$ipk_name tar -xOvzf $ipk_name ./data.tar.gz | tar -C / -xzvf - mkdir -p /opt/etc/ipkg echo "src armel http://ipkg.nslu2-linux.org/feeds/optware/cs05q1armel/cross/unstable" > /opt/etc/ipkg/armel-feed.conf wget http://mybookworld.wikidot.com/local--files/optware/sort_dirname.tar.gz tar xvfz sort_dirname.tar.gz -C / export PATH=$PATH:/opt/bin:. ipkg update *Read about what packages are available via optware at this link. Modify the bash path so you can execute ipkg easily /opt/bin/ipkg install nano nano .bashrc Change the path variable (at the top of the file) to match the image. Now you can add some additional processes to you NAS unit. For example, I am installing castget, a set it and forget it downloader for podcasts. /opt/bin/ipkg list ...will show all the possible packages that are currently available to install. If I just want castget or some other type of podcast downloader I can configure and let run automatically. /opt/bin/ipkg list | grep cast ...shows me all the available packages with the word "cast" in it. /opt/bin/ipkg install castget ...installs the castget package (If I change my mind and use something else I just use the keyword remove instead of install to remove castget from the system) Now I need to configure castget and add it to crontab so it does its job every day. For tips that apply to the older Blue Ring version of the WDWE see the following site for tweaks instead http://mybookworld.wikidot.com/ (Inspired most of my first attempts in WDWE hacking)

Kam Salisbury Linksys NAS200 and Linux

2010-07-21T03:04:24+00:00

The Linksys NAS 200 does not come with NFS type file sharing support, a critical service for die hard Linux folks. However, the Linksys NAS 200 does have FTP services and CIFS services. With just a few commands and installed packages, the lack of NFS turns out to not be a deal breaker for Linux at all.

For Debian based Linux folks, the easiest fix is to install SMBFS for your Linux distribution!

For RPM based distributions such as Fedora, look for the Samba Client package.

For Debian devottees the package is added via the shell prompt as easy as sudo apt-get install smbfs Then follow the example shown for the mount command like so sudo mkdir /mnt/nas sudo mount -t cifs //nas200ipaddress/PUBLIC\ DISK /mnt/nas -o user=you,uid=500,gid=500 *Ubuntu folks, uid=1000,gid=1000 may work better for you.

(Note: The old school smbmount smb mount file system type is buggy and was replaced by the cifs file system type in 2007.)

An alternative for Linux folks could also be curlftpfs for ftp mounts. Be cautioned though, the performance I experienced was buggy with large file transfers causing me to have to drop back to a standard ftp client for large files and bulk transfers. The cifs file system mount worked fine in all cases.

Of course, the same SMBFS package is just as easily added from the standard Add/Remove Programs menu selections standard in any Gnome, KDE or XFCE desktop.

Windows folks will find the NAS 200 really easy to use in the regular attach a drive letter to a share kind of way. For example, the following command works as advertised from the Start/Run input box as well as any Explorer or even Internet Explorer address input box. \\nas200ipaddress\sharename Even the FTP service or adding a Network Place (as either a windows share or FTP share) works great from Windows.

The Linksys NAS 200 has a built in http service used for configuration of the device. Not documented well is that any web browser client may be used to also view the files stored on the device. For example, the http service worked great streaming video stored on the Linksys NAS 200 to VLC across our home's wifi network. No lost frames or other issues. Just remember that any files you copy to the PUBLIC DISK share is read/write access for all defined users on the NAS 200. Your personal data should, of course, be saved in a share defined for your desired username. Configuration of these personal shares is accomplished via the web based interface. Just read the product manual for more info.

The Linksys NAS 200 requires SATA based disks utilized to store your data. Also on board are two USB ports for connecting USB Flash RAM drives. Since the Linksys NAS 200 supports configuring the two disks as a RAID 1 mirror, this configuration becomes the recommendation for folks needing fault tolerance at the disk level. Elsewhere on the Internet will say RAID is not a substitute for backups and in answer to this truth the two USB ports come into play. Depending on the quantity of data you need to backup, a Flash RAM drive or even external USB disk can be attached to one or both of the USB ports for easy duplication of your choice of data. Just be sure to store that backed up data somewhere safe that is not in the same building as your home network. This way (for example), should something bad happen at home, all your digital pictures will be safe somewhere else and one file restore away from being available again.

Summing It Up Be sure to read through the documentation before blaming performance or compatibility issues on the Linksys NAS 200. The Linksys NAS 200 is not a hardware device designed for anything larger than the small office or home office environment but its features and configured reliability options allow it to shine while tucked away on my home's network, just like it should.

Kam Salisbury Lexmark 4200 and Linux

2010-07-21T02:58:09+00:00

Using the Lexmark Printer & Fax as well as sharing the print service with Linux is easy if you follow this guide. Unfortunately you cannot share the FAX services but this is Linux and there are better choices for FAXing anyway.

Using Ubuntu (or your preferred Linux distribution), connect the Lexmark x4270 to your PC via the USB cord.
Use the printer settings dialogue to configure the printer but be sure to select "shared" and to change the print driver to the Lexmark Z42.

Windows clients can now connect to the shared printer via a URL similiar to http://linuxPCsIP:631/printers/4200_Series Be sure to select the Lexmark Z42 for the print driver as well.

Kam Salisbury Add the Virtualbox Yum Repo

2010-07-21T02:36:49+00:00

Many Open Source applications are adding yum repositories in addition to providing rpm downloads. Starting with revision 3.x.x, Virtualbox now has a repo file provided for easy download. Look at http://www.virtualbox.org/wiki/Linux_Downloads towards the bottom of the page.

Kyle Winfree Arduino SDWrite

2010-07-20T21:02:51+00:00

Alright, so it’s been done for 9 days now, and I’m just now getting around to making a blog post about it, but I have a working SD card writer. Basically, I took an existing example (that came from Ryan Owens (Spark Fun) using a library written by Roland Riegel) and modified it to be a log file generator. It works on the MicroSD Shield, http://www.sparkfun.com/commerce/product_info.php?products_id=9802. I hope to roll this into a library set of it’s own soon, so my program will reflect “initialize_log” and “write_to_log” functionality. Fun fun!

Richard Freeman rich0

2010-07-18T11:57:21+00:00

One minor issue with EC2 is that they supply the kernel, and that already caused difficulties with my first EC2 tutorial – the image I created doesn’t let you create a new snapshot from a running image since the EC2 kernel lacks loopback support, and I didn’t supply a matching kernel module.

Amazon has a nice guide on how to do it – here is a gentoo-specific one.

These instructions start from a working ami image created using my previous instructions. Go ahead and mount it and chroot into the image.

Install a kernel using emerge xen-sources
Be sure to enable xen support in the kernel config file. Here is a working config.
Build the kernel with make && make modules_install as usual
Copy the kernel image to /boot as usual.
Create /boot/grub/menu.lst, containing:
default 0 timeout 3 title EC2 root (hd0) kernel /boot/kernel root=/dev/sda1
While optional you might want to clean up the kernel source directory, or even remove it – you’re paying by the gb and the sources and object files are large.
Bundle it up with the instructions in the first guide, but on the ec2-bundle-vol command line add –kernel followed by a suitable kernel ID from the pdf linked above. For a 64-bit ami in the US-east region use aki‐427d952b

That’s it – upload, register, and boot it up!

I am currently maintaining two images at the moment:
64-bit: ami-5a43a933
32-bit: ami-5043a939

Both are running stable kernel and udev, and I’ll update them periodically for a while.

On both images I have an entry in root’s ssh authorized_keys so that I can more conveniently access these instances when I’m using them. If you use this for anything other than experimentation you should remove this before creating your image. I’d host a version with and without this, but that does cost money on S3, so consider yourself warned…

Filed under: gentoo

yonkeltron Great post about Emacs keyboard macros

2010-07-16T18:45:41+00:00

I always find great stuff on the emacs-fu blog but today I read a particularly-wonderful post about Emacs keyboard macros. Like the author, I’ve been a long-time Emacs user but never really got into keyboard macros because it’s been quite easy to produce an elisp one-liner in many cases. That being said, this seems like a great time to learn so I look forward to reading more on the topic of keyboard macros as well as learning some new tricks.

Thanks for a great post!

Alex Launi I need a floor in Amsterdam! Does anyone have a dutch floor??

2010-07-06T17:52:12+00:00

Dear Dutch foss community,

A friend and I are attending GUADEC this year, but we have plane tickets to fly into Amsterdam on the 24th of July. The problem? GUADEC isn’t until the 26th! Neither of us have ever been to Holland, and while 2 days is certainly not enough time to enjoy Amsterdam, we want to try. If anyone has a bed/couch/floor/stable/etc. that the two of us could sleep in/on/under the night of the 24th we’d be super appreciative, and of course you’d always have a place to stay wherever it is that I’m living when you need a place to stay (at the moment Philadelphia- a really great town if you want to come visit, seriously Philly rules!).

Of course we’ll take you out, or cook you a nice dinner in return for your hospitality, and promise not to make a mess.

If you have a floor or whatever that we can sleep on, feel free to either leave a comment or send me an email alex.launi@gmail.com!

Kyle Winfree Arduino on Mandriva

2010-07-03T12:49:10+00:00

The first hit I received when I searched for “Arduino Mandriva” was http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1259672641/2. For some reason, wget failed on me when I followed the listed directions. Instead, I just downloaded arduino-0018 and avr-* from ftp://blogdrake.serveftp.net/mandriva/2010.0/free/i586/ and avr-libc from ftp://blogdrake.serveftp.net/mandriva/2010.0/free/noarch/ to a local directory. I then added that directory to my list of repositories (custom – local file). For some odd reason I need to run it with root permissions to get serial port access, but it works.

I’ll note I tried this because the source from the Arduino website didn’t work out of the box, dependency issues.

Kyle Winfree 100 downloads in 367 days – it sounds unimpressive, but I’m happy

2010-07-02T19:47:58+00:00

“A high fidelity ungrounded torque feedback device: The iTorqU 2.0″
15 full-text downloads between 2010-06-10 and 2010-07-02
102 full-text downloads since date of posting (2009-06-29)
Congratulations! This paper has now been downloaded over 100 times!

To encourage readership, simply refer people to the following web address:
http://repository.upenn.edu/ese_papers/497

Kyle Winfree pgfplots

2010-07-02T19:40:27+00:00

A friend of mine presented his research from the past few months at the lab’s weekly meeting today. He used Beamer/LaTeX to create his slide show. I’m a fan of TeX, so I was impressed. I was more impressed when I came to learn that he used pgfplots to make his figures, rather than Matlab. Check out pgfplots at http://sourceforge.net/projects/pgfplots/. I want to point out that he simply exported his data (from Matlab, but he could have used Octave) to a csv file. He then made his plots within LaTeX so that he had ultimate control over the plots, and they really did come out nice. I thought eps (vector graphic) figures trumped jpgs (read as LaTeX trumps PowerPoint for science slides), but I’m excited to say that pgfplots trumps eps (which still reads as LaTeX trumps PowerPoint).

I’m starting to think that I might need to do a short presentation on LaTeX for my local LUG; they (we) have been desperately looking for presenters on Linux-ey topics. Maybe in another two or three months, after I get another paper or two at least submitted to a journal/conference.

Kyle Winfree Arduino and Linux Journal

2010-07-02T19:28:19+00:00

I can’t post a link to the article, since it’s not yet available at linuxjournal.com, but this month’s LJ issue just happens to cover the Arduino board! They cover plotting data using the Arduino debug serial command and kst. Very cool.

My mentee has just finished the wiring harness for all of our analog sensors (six in total). He’s working on placement of the sensors and plotting some of that data this weekend (though not with kst). I’ve started delving into the mp3 shield we got from sparkfun.com, and hope to get that working with the microsd card shield this weekend. I had to relocate the chip select (CS) pin on the lcd shield we have, as it interfered with the cable select for the mp3 player. It looks as if the MOSI/MISO pins can all be shared between the shields, so long as the cable select is activated before data is sent to the corresponding shield. Neat.

yonkeltron newhaven.rb hackfest tomorrow!

2010-06-30T14:00:54+00:00

Tomorrow, in New Haven, CT will be the “Ruby, White and Blue” Hackfest run by newhaven.rb. We’ll be working on a few projects including the group’s site and most likely some Prawn and ScosugBot stuff. Beginners and people interested in learning are more than welcome and we hope to have some excellent projects for people to get started on.

Fill out the RSVP form and we’ll meet at 6pm EST at Blue State Coffee on Thursday, July 1st. Bring a computer and let’s write some code.

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Kyle Winfree Gramian take three!

2010-06-24T10:18:20+00:00

I really lucked out. The octave-forge developer who has responded to my submission of gramian.m has been really helpful in identifying things I should do to improve the usefulness and robustness of my function. He has given examples of what should be done in some cases, and simply stated what should be done in others. The ball is back in my court now, as several additional changes are requested. This is great though; by the time I submit fftplot.m for review, I should have a very good idea of how to write high standards octave/matlab functions.

JonathanD fosscon... 2011?

2010-06-20T10:21:43+00:00

Fosscon ended just over 12 hours ago. I think I probably listened to the first or last 15-20 minutes of at least 10 different talks or workshops... and I loved it. It's 6am the following morning and I'm absolutely exhausted, but I'm also excited about what the future holds.

So, the good, the bad... We didn't get the turnout we'd hoped for, but at the end of the day I think everyone enjoyed themselves. The talks (or at least the parts I actually got to hear) were very good, and more importantly a lot of people from all over talked outside them about ways they could help each others... help their community. I think it says something of our speakers that after hearing just a tidbit here and there, I still felt fulfilled in every instance.

To me, that's probably one of the best things that comes out of this. These disparate groups and people from all over have made the connections that will tie them together in the future. They've learned of new resources, and also who might need the resources they can provide, and as a result the community grows stronger.

It's these connections that move us forward. In the foss world, one person can certainly make a difference, but a handful of people who share what they have and use it to do something new and amazing, they can change the whole world.

There was a lot of talk at fosscon about next year. There will be a next year. Too much good happened for there not to be, and these people, all those who attended, those who sponsored (linode, the Peer Directed Project Center, and of course our attendees themselves!), those who volunteered... they are fosscon's community, and it's going to happen again.

See you in 2011

Kyle Winfree Arduino

2010-06-18T10:34:08+00:00

I sent out an email to the Philadelphia Linux Users Group that I am part of, asking for advice related to microprocessors that would be easy to use and yet highly functional. To be honest, I didn’t think I would get much response, though I can’t say why I thought that. Really I should have expected otherwise, as that is exactly what happened.

I received several emails with really good information, and even one email asking what I had decided on using for my mystery project. I also asked a friend of mine from U of Penn, since we had talked about a microprocessor project using the Atmel AVR when I was there. He had more advice to offer than I expected too! I would like to publicly thank all those who helped provide the input that guided me to choosing a platform.

So what did I choose you might ask? Let me start by describing my project. This is a university funded project that will be conducted by a new student to our lab. ( I am his mentor for the summer.) We’re developing a medical device that can deterministically provide analog output to an actuator based on analog input. It was my friend from Penn who helped me to realize that this analog output, which is expected to be a combination of sine waves, is really just audio output. There just so happens to be a “shield” for the Arduino board that is an mp3 player (also plays ogg among others).

I know, I’m not being really descriptive here, but everything will be revealed in due time. We’ll be working with a physical therapist to test our device, after which we expect to publish a paper on the project in an academic journal/proceedings. I will of course post that paper here when it is time. Until then, please stay posted to hear about the progress of our project. Who knows, maybe in the next week we’ll have a “hello world” demo that shows the key features we want to develop in this little device.

JonathanD Heading North to fosscon.

2010-06-17T12:10:31+00:00

Tomorrow afternoon we'll begin our drive (about 5 hours) up to fosscon along with a few others from Philadelphia. Last time we made such a trip was SELF last year (we went to CPOSC too, but we took the train) and it was quite a bit of fun.

I believe we still have room for one on our return trip only, so if you find a way to get there but not home let me know!

The conference is being opened by members of BaseKamp, located in Philadelphia. BaseKamp presents a completely different view of open source culture, going beyond free software and into free arts and culture. Just the other night they did a great session on free art session.

I'm personally looking forward to the POSSE panel, where a group of educators who have just completed a week long POSSE course (http://teachingopensource.org/index.php/POSSE_RIT) on how to use open source in their classrooms will share with everyone what they learned.

I'm also looking forward to meeting Bryan Østergaard (http://kloeri.livejournal.com/), coming all the way from Denmark to talk about how to build a developer community around a project. All in all it should be great.

If you aren't already coming, take a look at http://fosscon.org/ to see whats what, and maybe to come along.

Kam Salisbury Podget Works on Cygwin

2010-06-13T19:01:50+00:00

Calling all stuck on Windows 7 folks! You don't need to give up your love of the bash prompt! Nay, not even a suspicious love for the korn shell either. Many command line utilities, scripts and programs work fine on Cygwin.

Cygwin 1.7.x (released Dec 2009) provides a Linux like environment on a Windows 2000 or newer platform. Yes, even on a Windows 7 64bit platform such as my power sipping Atom processor machine.

Podget (by Dave Vehrs) is a simple but flexible command line podcast aggregator with support for categories & folders, importing servers from OPML lists & iTunes PCAST files plus automatic playlist creation and cleanup.

If your Cygwin environment is already setup, be sure to add support for iconv (provided by libiconv). The stock libiconv2 support will not be recognized by podget as being installed for its normal use.
Download the latest Podget source (I used podget-0.6.tar.gz)

From the command line tar -xzvf podget-0.6.tar.gz
cd podget...
make && make install

Run podget once to auto-create the .podget directory then edit the .podget/serverlist file to your liking.

Hint: To get you started, why not check out my serverlist file attached to this post?

Hint #2: Since this is command line program, you can use a batch file to do cool things like email your cell phone when its completed its podcast downloading run.

Kam Salisbury Cygwin Works on Windows 7

2010-06-13T18:58:31+00:00

Cygwin is a great application that provides a bash shell compatible environment on a Windows desktop. The latest (1.7.5) Cygwin release will install and operate as expected on both 32 bit and 64 bit Windows 7 platforms. Network communication also works, if you edit the Windows 7 firewall outbound rules to allow cygwin to communicate.

Basically, the security built into Windows 7 does not see the shell environment the same way it would a regular windows API application - so Windows 7 never stops to ask you if it should add a rule allowing the application Cygwin to access the network. The result is wget (and other network utility applications) seem to never respond or take a very long time to 'time out'.

Great, now lets add a Windows 7 firewall outbound rule for Cygwin to access the network. These instructions may work (with slight modification) as a guide for other firewall applications and previous versions of Windows as well.

Click the Windows Start Button (usually in the lower left corner of the Windows desktop). Type in a search term of firewall to locate and click on the link for Windows Firewall with Advanced Security.
On the left hand side of the Windows Firewall configuration screen, select Outbound Rules.
On the right hand side of the Windows Firewall configuration screen, select the link for a New Rule... (the New Rule wizard will now open).
Select Program because the rule is being created for the exclusive use of a specific program (the installed Cygwin shell).
Be sure to point the rule at the specific shell you are using with Cygwin. I use good 'ol bash (as pictured).
Select Allow the connection to allow Cygwin to use the network outbound path.
If you have a domain or are using Cygwin at a Starbucks then selecting the boxes for Domain and Public make sense. If your only using Cygwin on your home network and you have defined your home network as Private in Windows 7 then just selecting Private should work. It is a best practice to build firewall rules with only the necessary settings so try to avoid just selecting everything when you probablly do not need to.
I named the rule bash but the wizard will accept almost anything. Using bash made sense in case I decide to install an alternate shell in the Cygwin environment.
Viola' Cygwin should now be able to wget, rsync and other things like it should have in the first place.

Did the above walk through style work for you? Are you a Windows hater? Feel free to comment, I promise to try to understand your point of view.

Kam Salisbury Check Lexmark for Linux Print Drivers

2010-06-13T18:48:10+00:00

A while ago... I had purchased a Lexmark X4650. Nice device, great features but no Linux compatibility.

I checked today and there they are! Linux print drivers in both .deb and .rpm packages!

The installer does not work correctly on the Ubuntu 10 LTS platform but hey, there is something there to tinker with now.

Thanks Lexmark, you may be OK after all.

Update: On the 64 bit version of Ubuntu 10 LTS I am currently running... a solution to getting the Lexmark printer driver to install was to find this post http://ubuntuforums.org/showthread.php?t=474790 and install getlibs,

Kam Salisbury Android Tips

2010-06-13T18:42:46+00:00

These Andriod tips are from hours of un-scientific testing, review of other web content and plain old trial/error. While these tips worked as expected on my Verizon branded HTC Driod Eris, your device could be different so please excercise caution as necessary when applying these tips to your phone.

Conserve power: Use menu taps... Settings, Wireless Controls, Mobile Network Settings, un_check Enable Always On Mobile Network. You lose instantanious twitter and other social network updates but gain better battery life.

Conserve power: Use menu taps... Settings, Sound & Display, Check Disable Auto Backlight, then set Brightness to a sane level. You lose blinding but vibrant display in sunlight. You gain enjoying the sunlight instead of tapping on your phone.

Conserve power: Use menu taps... Settings, Locale & Text, Touch Input, Text Input, un_check Vibrate When Typing. You lose short buzzing feedback as you type using the on screen keybord. You gain bettery battery life and retain tactile sensations in your finger tip.

Conserve power: Link only a main Google gmail account, not an associated non Google account. Android uses the linked account for all Google services so trying to use an associated account such as Google apps will not work. Android will just keep trying to use the associated account to login in the background and run down your battery. Basically, Andriod can only handle one Google login account so use one that is a real account.

Conserve power: Don't run services you don't use, turn them off. Use menu taps... Settings, Applications, Manage Applications, tap menu, Filter, Running Applications, select the application to kill (stop running), Force Stop.

Recommend application: (free) Aldiko, an ebook reader with links to popular free text downloads.

Recommend application: (free) GDocs and GDocs Notepad, both work well but GDocs allows web based edits to non text documents.

If your updated to Android firmware version 2.1...

Conserve power: Use menu taps... Settings, Wireless & networks, Mobile networks, un-Check Enable always-on mobile data.

Conserve power: Use menu taps... Settings, Sound & Display, Brightness, un-Check Automatic Brightness and then set Brightness to a sane level.

Conserve power: Use menu taps... Settings, Language& keyboard, Touch Input, text input, un-Check Vibrate when typing.

Conserve power: Don't run services you don't use, turn them off. Use menu taps... Settings, Applications, Running services, select the desired application, click Stop.

Kam Salisbury More website changes (sorry)

2010-06-13T18:36:57+00:00

My web host (Dreamhost.com) is performing some late spring cleaning and moving my website(s) to another server(s). It is a good time for me to update many literal paths with DNS names and many other things... so... during the next week or so some (hopefully not all) of my web site images, links, content, etc may be broken. No worries OK? I will get it all straightened out.

Alex Launi GUADEC, an interview in 5 moments

2010-06-11T16:42:12+00:00

Feeling the crushing need to fit in, here are the answers to five questions from guadec.org.

Who are you and what do you do?

I am Alex Launi, I’m 22, live in South Philadelphia, PA, USA, 5’8″ (172cm) tall, and weigh 157lbs (71.2kg). I’m about to graduate from Temple University with a bachelors of science in computer science. I work on Banshee, Do, and some other random projects here and there. I’m a hardcore cyclist, and I’ll probably be spiraling into a deep depression during guadec from separation anxiety with my bike. I love modern literature, my favorite writer is either Cormac McCarthy, James Joyce, or Thomas Pynchon depending on where and when you ask me. I like philosophy, detest the “Linux is about choice” mantra, and have never successfully done a magic trick.

How did you get into GNOME?

I’ve never been inside of a gnome, I don’t think I ever will. I’ve never had a first hand gnome encounter but my impression is that they’re very short. I don’t think I could ever fit inside of one.

Why are you coming to GUADEC?

To show off my sweet summer of code work, meet people I know from the internet, meet new people who are involved with gnome, network to try and find an awesome job, travel, drink fancy beer.

In 1 sentence, describe what your most favorite recent GNOME project has been. (Doesn’t have to be yours!)

I think Telepathy is the coolest thing there is, I want to see it used everywhere, for everything (do you see this Collabora? you can hire me if you want).

Will this be your fist time visiting the Netherlands?

I’ve been to never-never land, but never the Netherlands. Unless maybe never-never land was renamed to the Netherlands in post-war partitioning.

Kyle Winfree Response from Octave-Forge

2010-06-10T11:44:11+00:00

I’ve been meaning to make this post for a few days now, which speaks of how busy I am with qualifying exams and my university research project. I received an email from one of the octave-forge developers. He has asked that I make several changes (all good things I hadn’t thought of with my limited programming experience), and then resubmit. I plan to make an hour or two next week to do just that.

Kam Salisbury Fedora 13 is out...

2010-06-09T01:48:29+00:00

Ahhh... the smell of a new Linux distribution. My tips will help you smooth your post install customization and add much sought after features not included in the base distribution.

Install yum-plugin-fastestmirror (The yum utility plugin fastest mirror will make system updates and application installs generally faster as it picks the fastest Fedora mirror so you don't have to)
Enable rpmfusion.org (RPMfusion has applications that are not included in the base Fedora distribution due to licensing gobbledygook)
*See http://www.kamsalisbury.com/code for an automation bash script example
Install VLC (The applications vlc and mozilla-vlc will handle just about any media format on the internet today)
Install realcrypt (Encrypt your personal data. Use mount options uid=500,gid=500 so that you can read the encrypted volume as a non root user)
Use a USB flash drive to install your Fedora system (Its more green than creating yet another aluminum coaster)

Need more? Try http://www.fedoraguide.info or http://www.fedorafaq.org both a revision or so behind but still with great information.

Kyle Winfree Blogger Relocation Program

2010-05-27T14:50:47+00:00

It’s simple really. I figured that I might as well just host my own blog. So thank you to wordpress.com, but I’ll be using your software on my own hardware now.

Richard Freeman rich0

2010-05-26T13:53:06+00:00

I love what Google has been doing, and they’ve made huge contributions to FOSS. However, I have to join the chorus of those who are concerned with their lack of distro-friendliness.

The start of my saga was Gentoo bug 320407. Apparently Google re-bundled swt in their android SDK, and the version they re-bundled breaks sometimes.

So, the solution is to not install swt, and patch their android script so that it uses the system library. I still have to figure out which version of swt they re-bundled so that I can try to match it. Maybe that won’t be much work.

Then I need to look at all those other libraries and see which of those can go. I’ll need to patch in their paths, and I’ll need to figure out which upstream versions they re-bundled so that I can set the correct dependencies. Maybe each of those won’t be much work. Maybe some poor user will get burned when it turns out that they modified one of them and I miss it in testing.

Oh, and every time they do a new release they’re not going to tell me if they upgraded one of those bundled libs to a newer API/etc, so maybe if I’m lucky I’ll spot problems during testing and not burn users. Maybe that isn’t too much work either.

Maybe each of these things won’t be much work, but this is already sounding like a royal pain to me. It is also a recipe for end-user problems.

Let me pick my next favorite Google package – chromium. I have a chromium upgrade pending that I’ve been postponing. Building and installing chromium takes hours on my system (an old Athlon 64 3200+). Actually, building chromium probably isn’t the problem – it is building the other half-gigabyte of re-bundled dependencies that get rebuilt every time I upgrade chromium, even though I already have most of them on my system (and if I didn’t the package manager would take care of that for me – ONCE).

My hat is off to the chromium maintainers because they’ve done a good job managing it, and I understand that they’re trying to strip out the embedded libs. However, the project facing them makes my android headaches seem like a trifle.

Google – just use and list dependencies! If you want to have an alternate all-in-one package for those without package managers, feel free – other projects do it. However, if Mozilla can play nice with distros, you can do it too.

All that said, I have no objections to embedding contributed libraries in the sdk itself – the part used to build and test android apps. In this case app developers need to build and test their apps against the libraries that will be on target devices and not their development workstation. Since no code will run natively (except perhaps on an emulator) there aren’t really the usual compatibility and security issues associated with this.

Filed under: gentoo

Alex Launi This SOC project is dedicated to Morrissey

2010-05-25T00:33:45+00:00

Today is the summer of code start day, and like every other excited summer of code student, I got drunk instead of working! I had a 6 pack of Magic hat, and now I have a mockup of what the now playing source will look like af the end of my project. The biggest difference between the final product and this, is that the final product will actually work.

Notice the buttons in the top right? Clicking will change the now playing source contents to last.fm, wikipedia, or back to your regularly scheduled programming. Pretty nifty right? If you’re interested, you can follow my work in written form here, or here (literally here, because I’ll be blogging about it), or in code form over here. You can actually already check out what I have so far, which is what you see above. It’s not that cool yet so I wouldn’t bother, but it’s going to get cool- so I would bother.

That’s all for today! And happy (belated) birthday Morrissey, you’re a cool 51 this year.

Kyle Winfree FFT Plot

2010-05-22T01:15:29+00:00

I think I have another idea; one for a function near and dear to my heart, fft analysis of audio.

Alex Launi I’m going to GUADEC

2010-05-21T19:35:15+00:00

Thanks to the folks on the GNOME travel committee I can now say

Thanks!! I can’t wait!

yonkeltron Creating a Ruby DSL

2010-05-14T13:27:09+00:00

Tons of people in the Ruby community go on and on about domain-specific languages (abbreviated DSL) and how wonderful they are. In most cases, I agree with them. I began to wonder how I could go about leveraging Ruby’s awesomely-flexible syntax to create my own DSL. To illustrate my quest, I have written this article. It assumes you know Ruby. The example details are completely fictitious and just contrived enough to be interesting. I promise, the code will be the main focus and I will link/point to other resources which might be helpful to budding DSL designers like myself.

Problem

The Dream Castle Architectural Firm (D-CAF, among friends) wants a tool which it can use for very high-level prototyping of custom homes. They need it to be understandable by both computers and humans. It only needs to keep track of the following things:

Houses – Each house has a name
Floors – Each house has multiple floors. Each floor has a number
Rooms – Each floor has multiple rooms and each room has a type

The only other requirement is that the DSL be translatable to plain English so that they can show it to customers. No problem.

Solution

The DSL for the high-level specification of custom houses will look like the following:

CustomHouse.build :home do
  floor(1) {
    room :den
    room :kitchen
  }

  floor(2) {
    room :bedroom
    room :bathroom
  }
end

That’s it. You specify that a house should be built, that it has a name, some floors and each floor has some rooms. Simple, easy and 100% pure Ruby. Notice the cunning usage of both do/end and bracket notation for defining blocks. The outer block passed to CustomHouse#build uses do/end syntax while the blocks passed to House#floor use the bracket syntax. These could easily be reversed (or combined or whatever) but it makes it look pretty and helps to visually differentiate things so that you (the developer) and the user (the architect) can things more clearly. Plus, when you print the output (calling to_s on the instance of House which gets returned), you get the following wonderful text:

House named home has 2 floors.
Floor 1 has 2 rooms (den, kitchen)
Floor 2 has 2 rooms (bedroom, bathroom)

It’s a small house, don’t be a wiseacre. So, how can such a DSL be built?

Implementation

Let’s write the implementation for this together. First, we’re going to start of with a module named CustomHouse. In Ruby, modules are just classes so we’ll define a class method called build which will behave like a factory method.

module CustomHouse
  def self.build(name, &block)
    house = House.new(name)
    house.instance_eval(&block)
    return house
  end
end

As you can see, the method takes two params, a name and a block. The first thing that it does is create an instance of the House class (which we have not yet defined) passing in the name parameter. Second it calls instance_eval on the house passing in the block. This ventures into the territory of metaprogramming which is great fun but beyond the scope of this document, though I am sure others have used it for DSL construction (coincidentally, if you are interested in Ruby metaprogramming, buy this book). Suffice it to say that it executes the supplied block in the context of the House instance. Finally, the CustomHouse#build method returns the instance of House.

(There are those who believe that *any* type of eval is fundamentally evil. I have been taught this many times and I try to avoid using eval on an actualy string whenever possible. Still, someone with a better understanding of Ruby internals might be able to better explain if this in any better.)

Next, let’s define what the code for the House class looks like. As a note, it will be defined in the CustomHouse module, technically making the fully-namespaced name of the class CustomHouse::House.

class House
  attr_accessor :name, :floors

  def initialize(name = '')
    @name = name.to_s
    @floors = []
  end

  def floor(number, &block)
    fl = Floor.new(number)
    fl.instance_eval(&block)
    @floors < < fl
  end

  def to_s
    str = "House named #{@name} has #{@floors.length} floors.\n"
    @floors.each do |f|
      str << f.to_s
    end
    str
  end
end

The above code should appear relatively simple. The House class has only a few methods. First, it has a constructor function which takes a name and a block, setting the name as an instance variable and another instance variable, @floors, which is just an empty array. Next, it has a method called floor which takes a number and a block. The guts of this method should look familiar to you because it mimics almost exactly the build factory method defined on CustomHouse. Finally, it has a to_s method because of the requirement that the DSL be translatable to plain English for clients to check out.

If we can just dwell for a moment on the floor method, notice that, it too, takes a block and uses instance_eval. It then adds the newly-constructed instance of Floor to the array in @floor. Let’s look at the Floor class now.

class Floor
  attr_accessor :number, :rooms

  def initialize(number = 0)
    @number = number
    @rooms = []
  end

  def room(type)
    @rooms < < Room.new(type)
  end

  def to_s
    str = "Floor #{@number} has #{@rooms.length} rooms ("
    @rooms.each do |r|
      str += "#{r.type}, "
    end
    str.chop!.chop!
    str += ")\n"
    str
  end
end

There shouldn’t be anything confusing about the above code as it doesn’t use any sort of block eval. In fact, the only thing left to look at is the class for Room which is even less impressive.

class Room
  attr_reader :type

  def initialize(type)
    @type = type
  end
end

That’s it. Seriously, that’s the entire implementation of the DSL. You pass a block to CustomHouse#build which gets executed in the context of a new instance of House. The block calls the House#floor method with a block which in turn gets executed in the context of a new instance of Floor. The Floor#room method adds new Room instances to the class and that’s basically it.

Here’s all the code together with the example:

module CustomHouse

  def self.build(name, &block)
    house = House.new(name)
    house.instance_eval(&block)
    return house
  end

  class House
    attr_accessor :name, :floors

    def initialize(name = '')
      @name = name.to_s
      @floors = []
    end

    def floor(number, &block)
      fl = Floor.new(number)
      fl.instance_eval(&block)
      @floors << fl
    end

    def to_s
      str = "House named #{@name} has #{@floors.length} floors.\n"
      @floors.each do |f|
        str << f.to_s
      end
      str
    end
  end

  class Floor
    attr_accessor :number, :rooms

    def initialize(number = 0)
      @number = number
      @rooms = []
    end

    def room(type)
      @rooms << Room.new(type)
    end

    def to_s
      str = "Floor #{@number} has #{@rooms.length} rooms ("
      @rooms.each do |r|
        str += "#{r.type}, "
      end
      str.chop!.chop!
      str += ")\n"
      str
    end
  end

  class Room
    attr_reader :type

    def initialize(type)
      @type = type
    end
  end
end

h = CustomHouse.build :home do
  floor(1) {
    room :den
    room :kitchen
  }

  floor(2) {
    room :bedroom
    room :bathroom
  }
end

puts h

Try running it and see what happens! Then try writing other definitions for custom houses and experience the theoretical joy of the hypothetical architectural firm.

DSL construction techniques

For clarification and context, I’d like to share some other, smaller examples which build on this technique and demonstrate one more.

Behold, a DSL for feeding Pandas:

Panda.feed {
  nom :bamboo
  nom :chocolate
}

The implementation of this is both simple and straightforward.

class Panda
  def self.feed(&block)
    panda = Panda.new
    panda.instance_eval(&block)
  end

  def nom(food)
    #whatever
  end
end

Since the block is evaluated in the context of the new Panda instance, it has access to the Panda#nom method. For people deathly afraid of eval, there is this alternative syntax:

Panda.feed do |p|
  p.nom :bamboo
  p.nom :chocolate
end

Which is implemented with yield instead of instance_eval like so:

class Panda
  def self.feed
    yield Panda.new
  end

  def nom(food)
    # whatever
  end
end

For a wonderful and inspiring treatment of Ruby DSLs and associated patterns, see the most-excellent talk on the matter given by Jeremy McAnally at the 2009 Mid West Ruby Conference.

Conclusion

DSLs are a fantastic tool which can help to simplify complicated and repetitive tasks. Ruby is very good for creating DSLs but it is not the only good tool out there. I advise you look into the creation of DSLs with Scala and, the best DSL-creation tool there ever was, Lisp Macros.

I am interested in improving this tutorial for the benefit of those programmers who wish to learn about DSL construction but don’t know where to start.

Alex Launi GSOC Weekly Report Week 1

2010-05-12T16:46:28+00:00

No news! Exams at my school aren’t over yet, so I’m still studying and wrapping up loose ends. It turns out I’ll be graduating in August instead of in January like I expected, but I’ll also be taking one class over the summer to finish up my degree. What class am I taking? I’m taking a class about the geology of disaster movies. Sounds awesome, right?

Tomorrow is the last day of exams so 5/13 is GSOC GO DAY. Sweet! We’re in the community bonding period now, and lucky me- I’m already pretty familiar with the Banshee community. Can’t wait to get started and be finished with finals.

yonkeltron Continuity Control presents at Finovate

2010-05-11T21:46:52+00:00

Pleased to say that Continuity Control has gotten some rather positive feedback while presenting at this year’s Finovate! While not the only feedback, some of my favorites here:

Tweets: one – two – three – four – five

Photos: one – two

Truly proud of be part of the team.

Tharun Kumar Allu Heartbeat on CentOS

2010-05-05T11:33:50+00:00

When you try to install heartbeat using yum when the dependencies are not installed you get the following error.


yum -y install heartbeat

useradd: user hacluster exists
error: %pre(heartbeat-2.1.3-3.el5.centos.x86_64) scriptlet failed, exit status 9
error:   install: %pre scriptlet failed (2), skipping heartbeat-2.1.3-3.el5.centos

Due to this error heartbeat is not installed.

A simple fix is install heartbeat again using yum and that should solve the problem until someone upstream fixes the installer.

Alex Launi I’m a Google Summer of Code Student!

2010-04-26T21:21:51+00:00

Today Google made the announcement of accepted summer of code proposals! I’m one of them! Looks like I’ll be spending my summer hacking on Banshee instead of driving a forklift, serving coffee, washing dishes, or any of the other jobs I’ve been seeing on craigslist. What will I be doing? Here’s a copy of the proposal I submitted.

The Now Playing source is an underutilized component of the Banshee user interface. The goal of this proposal is to extend that interface to be a source for extended information about the currently playing media. After the completion of this project, the Now Playing source will replace (or augment) the current behavior of the Context Pane, but also be extended to account for other types of media such as podcasts, videos, audio books, and internet radio.

The current implementation of the context pane is cool, but its location is awkward. It’s in the library, but displays information related to the currently playing media, and is only be relevant for music, not video or podcasts so when you’re listening to a podcast it just says “waiting for playback to begin…” Wait what? Playback has begun!

The now playing source as is, is kind of a waste of some really great space. The album art display is beautiful looking, but it’s static. If you’re listening to an album there’s no information there that isn’t available elsewhere more conveniently. The text displayed is the same. This area is perfect for displaying extra information about the currently playing song such as lyrics, last.fm similar artist information, or information from wikipedia, as well as OpenVZ visualizations, all of which should be toggleable.

My project will be to add API to the context sources so that they can be viewed for any media type to which they are relevant, add API to the now playing source to allow context sources to display their content there, create a widget to allow changing what context source is being viewed, and tie it all together into an extremely compelling, and immersive user experience.

Special thanks to Gnome, Google, Banshee, and alexk! I’m really excited, this is going to be a great summer. Stay tuned for updates!