version page 6 - Dave's Blog

Awesome Movies Unknown to Me

2007 Aug 12, 2:50Thanks to Netflix I've been able to enjoy several movies that I'd never heard of.



Brick is a classic PI film set in a modern high school. Its fun figuring out which high school students correspond to which film noir archetypes.

Primer is a sci-fi movie but it doesn't focus on action or effects. Its like watching an excellent Twilight Zone episode. I hate to describe this any further for fear of giving something away.

The Amazing Screw-On Head is an animated version of the one shot comic. It feels like the 1800s precursor to the The Venture Bros. and stars Screw-On Head, a steam-punk robot head thing and Abe Lincoln's top spy for occult matters.

The Quiet Earth is the movie version of the book about a man who awakes one day to find himself alone(... or is he?) It was made in the 80s and in Australia but don't hold that against it.scifi primer movie amazing screw-on head personal netflix brick the quiet earth

Which which - Batch File Hackiness

2007 Aug 9, 5:41To satisfy my hands which have already learned to type *nix commands I like to install Win32 versions of common GNU utilities. Unfortunately, the which command is a rather literal port and requires you to enter the entire name of the command for which you're looking. That is 'which which' won't find itself but 'which which.exe' will. This makes this almost useless for me so I thought to write my own as a batch file. I had learned about a few goodies available in cmd.exe that I thought would make this an easy task. It turned out to be more difficult than I thought.

for /F "usebackq tokens=*" %%a in ( `"echo %PATH:;=& echo %"` ) do (
    for /F "usebackq tokens=*" %%b in ( `"echo %PATHEXT:;=& echo %"` ) do (
        if exist "%%a"\%1%%b (
            for  %%c in ( "%%a"\%1%%b ) do (
                echo %%~fc
            )
        )
    )
)

The environment variables PATH and PATHEXT hold the list of paths to search through to find commands, and the extensions of files that should be run as commands respectively. The 'for /F "usebackq tokens=*" %%a in (...) do (...)' runs the 'do' portion with %%a sequentially taking on the value of every line in the 'in' portion. That's nice, but PATH and PATHEXT don't have their elements on different lines and I don't know of a way to escape a newline character to appear in a batch file. In order to get the PATH and PATHEXT's elements onto different lines I used the %ENV:a=b% syntax which replaces occurrences of a with b in the value of ENV. I replaced the ';' delimiter with the text '& echo ' which means %PATHEXT:;=& echo% evaluates to something like "echo .COM& echo .EXE& echo .BAT& ...". I have to put the whole expression in double quotes in order to escape the '&' for appearing in the batch file. The usebackq and the backwards quotes means that the backquoted string should be replaced with the output of the execution of its content. So in that fashion I'm able to get each element of the env. variable onto new lines. The rest is pretty straight forward.

Also, it supports wildcards:

C:\Users\davris>which.cmd *hi*
C:\Windows\System32\GRAPHICS.COM
C:\Windows\System32\SearchIndexer.exe
D:\bin\which.exe
D:\bin\which.cmd

which cmd technical batch for

Two-for Script File

2007 Aug 6, 5:40I was messing with the XSLT to XSL Converter source which is a javascript file that can be run with cscript.exe. I've changed it to be like a very basic version of xsltproc that simply runs an XML file through an XSLT. I also wanted to run this from the command prompt without writing "cscript ..." everytime. I decided to make like perl programmers I've seen and make a JS file that works as a batch file and a JS file at the same time.

Here's a basic version of what I ended doing applied to a 'hello world' script named helloworld.cmd:

/* 2> NUL
@echo off
cscript /e:javascript /nologo "%~f0" %*
@goto :eof

    Hello World
        Says 'Hello world.' when you run it.
*/

var outText = 'Hello world.';
WScript.Echo(outText);

Running this on a command prompt gives the following:

C:\Users\davris>helloworld

C:\Users\davris>/*  2>NUL
Hello world.

However, after a little more experimentation I found this was slightly overkill for my purposes since if I rename the file to helloworld.js and just type its name like a command it is run by cscript:

C:\Users\davris>helloworld
Microsoft (R) Windows Script Host Version 5.7
Copyright (C) Microsoft Corporation. All rights reserved.

Hello world.

So this time I didn't need all that but if ever in the future I need to run a batch file then a JS file I can do it with one file...cmd js technical cscript batch xslt xsl javascript

Backup Notes

2007 Jul 13, 8:30I bought an external backup drive a few weekends ago. I've previously setup a Subversion repository so I decided to move everything into the repository and then back it up. So in went the contents of all of my %USERPROFILE% and ~ directories with a bit of sorting and pruning. Not too much though given its much easier to dump in everything and search for what I want then to take the time to examine and grade each file. What follows are the notes I took while setting this up. It takes me a bit of time to look up the help on each command so I figure I'll write it all down here for the benefit of myself and potentially others...

Setting Up the Backup Drive For Linux
I first changed the filesystem on the drive to ext3. I plugged it into my USB2.0 port and ran fdisk:

sudo fdisk /dev/sda

Useful commands I used to do this follow mostly in order:

m

help

p

print current partitions

d

delete current partition

n

create new partition (I used the defaults)

w

write changes and exit

Then I formatted for ext3.

sudo mkfs.ext3 /dev/sda1

I made it easy to mount:

sudo vim /etc/fstab
# added line to end:
/dev/sda1 /media/backup ext3 rw,user,noauto 0 0

I setup the directory structure on the disk

mount /media/backup
sudo mkdir /media/backup/users
sudo mkdir /media/backup/users/dave
sudo chown dave:dave /media/backup/users/dave

After all that its easy to make a copy of the Subversion repository:

mount /media/backup
cp -Rv /home/dave/svn /media/backup/users/dave/
umount /media/backup

Next on the agenda is to add a cron job to do this regularly.

Subversion Command Reference
On a machine that has local access to the Subversion repository you can check out a specific subdirectory as follows using the file scheme:

svn co file:///home/dave/svn/trunk/web/dave%40deletethis.net/public_html

Note also that although one of my directories is named 'dave@deletethis.net' Subversion requires the '@' to be percent-encoded.
Other useful subversion commands:

svn help

help

svn list file:///home/dave/svn/

list all files in root dir of svn depot

svn list -R file:///home/dave/svn/

list all files in svn depot

svn list -R file:///home/dave/svn/ | grep \/$

list all directories

svn status

List status of all files in the working copy directory as in - modified, not in repository, etc

svn update

Brings the working copy up to date wrt the repository

svn commit

Commit changes from the working copy to the repository

svn add / move / delete

Perform the specified action -- occurs immediately

Setting up Windows Client for Auto Auth into SVN
When using an SVN client on Windows via svn+ssh its useful to have the Windows automatically generate connections to the SVN server. I use putty on my Windows machines so I read the directions on using public keys with putty.

putty.exe dave@deletethis.net
cd .ssh
vim authorized_keys # leave the putty window open for now
puttygen.exe
Click the 'generate' button
Move the mouse around until finished
Copy text in 'Public key for pasting into OpenSSH authorized_keys file:' to putty window & save & close putty window
Enter Key passphrase & Comment in puttygen
Save the private key somewhere private
pageant.exe
'Add Key' the private key just saved.

Checking out using Tortoise SVN
On one of my Windows machines I've already installed Tortoise SVN. Checking out from my SVN repository was really easy. I just right clicked in Explorer in a directory and selected "SVN Checkout...". Then in the following dialog I entered the svn URI:

svn+ssh://dave@deletethis.net/home/dave/svn/trunk/web/dave%40deletethis.net/public_html/

Note again that the '@' that is part of the directory name is percent-encoded as '%40' while the '@' in the userinfo is not.

Windows Command Line Check Out
On my media center I didn't want to install Tortoise SVN so rather I used the command line tool. I setup pageant like before the only difficulty was getting the SVN command line tool to use putty. With the default configuration you can use the SVN_SSH environment variable to point at a compliant SSH command line tool. The trick is that its interpreted as a backslash escaped string. So I set mine thusly:

set SVN_SSH=C:\\users\\dave\\bin\\putty\\plink.exe

The escaping solved the vague error I received about not being able to create the tunnel.backup technical personal windows svn linux subversion

Unspun IE List

2007 Jun 21, 2:38Unspun is a social list creation website from Amazon. For instance, you could create a list named 'Most Desired Features for Next Version of Internet Explorer' and users of Unspun fill in and rank the answers. There's a mix of serious answers that are excellent suggestions, fan-boy answers that are lame, uninformed answers that are already implemented, and hilarious answers that are awesome. The following is the very short unsorted list of the awesome suggestions.

Innovative Anti-Phreaking Technology

Given the work done in IE7 on anti-phishing, subsequent work on anti-phreaking just makes sense.

AXELROD 2.8 Acceleration with XML Bindings

I'm not sure what AXELROD 2.8 is but accelerating it sounds good. Also I enjoy binding things to XML so...

Larger Buttons for My Mighty Fingers

For maximum humor this should be read by Richard Horvitz as Zim of Invader Zim. This one makes me laugh every time I read it.

amazon personal ie humor nontechnical

Wiimote wiissues

2007 Jun 7, 5:29The other day I had the best idea for my Wii remote. Clearly I should use it to control the rotation of Tetris pieces in my N-dimensional Tetris game Polytope Tetris. One of the issues I described with Polytope Tetris is user input. Given a Wii remote the user could rotate a piece through 3 dimensions in a manner that's much easier to adjust to than particular keys on the keyboard.

Anyway, I did a little research into how this might work. I knew that the Wii remote used infrared for absolute positioning and Bluetooth for everything else (LEDs, speaker, accels.) I bought a Bluetooth adapter for my PC after realizing that none of my computers had one already. I used GlovePIE to ensure that my Wii remote could connect and successfully communicate with my computer. GlovePIE is actually pretty cool -- it provides a simple script layer over the Wii remote to control things like your mouse.

Since Polytope Tetris is in Java I looked for and found a Java library for operating with the Wii remote and a long forum thread discussing its use. I then read up on Bluetooth in Java. Apparently JSR 82 is the name of the standard that describes the API a Bluetooth stack should expose in Java. That is, to get Bluetooth working in Java one needs an additional package for Java that actually implements the Bluetooth Java API. This package would depend on the system so I suppose I can't fault Sun for not including it... Where to find such a package? I found a comparison list of implementations and tried the ones that support javax.bluetooth. None of them worked for me because none can address USB devices it seems or they cost money and I couldn't get the trial version working. I also tried bluesock (not listed on the previous list) which seemed promising and could produce an address for my Wii remote as a connected device but couldn't use that address.

And I thought that after I found the Wii remote Java library it would be easy... Oh well...java bluetooth wii technical remote jsr82 tetris polytopetetris wiimote

New XSLT - IE7 XML Source View Upgrade Part 2

2007 May 11, 8:55Last time, I had written some resource tools to allow me to view and modify Windows module resources in my ultimate and noble quest to implement the XML content-type fragment in IE7. Using the resource tools I found that MSXML3.DLL isn't signed and that I can replace the XSLT embedded resource with my own, which is great news and means I could continue in my endevour. In the following I discuss how I came up with this replacement for IE7's XML source view.

At first I thought I could just modify the existing XSLT but it turns out that it isn't exactly an XSLT, rather its an IE5 XSL. I tried using the XSL to XSLT converter linked to on MSDN, however the resulting document still requires manual modification. But I didn't want to muck about in their weird language and I figured I could write my own XSLT faster than I could figure out how theirs worked.

I began work on the new XSLT and found it relatively easy to produce. First I got indenting working with all the XML nodes represented appropriately and different CSS classes attached to them to make it easy to do syntax highlighting. Next I added in some javascript to allow for closing and opening of elements. At this point my XSLT had the same features as the original XSL.

Next was the XML mimetype fragment which uses XPointer, a framework around various different schemes for naming parts of an XML document. I focused on the XPointer scheme which is an extended version of XPath. So I named my first task as getting XPaths working. Thankfully javascript running in the HTML document produced by running my XSLT on an XML document has access to the original XML document object via the document.XMLDocument property. From this this I can execute XPaths, however there's no builtin way to map from the XML nodes selected by the XPath to the HTML elements that I produced to represent them. So I created a recursive javascript function and XSLT named-template that both produce the same unique strings based on an XML node's position in the document. For instance 'a3-e2-e' is the name produced for the 3rd attribute of the second element of the root element of the XML document. When producing the HTML for an XML node, I add an 'id' attribute to the HTML with the unique string of the XML node. Then in javascript when I execute an XPath I can discover the unique string of each node in the selected set and map each of them to their corresponding positions in the HTML.

With the hard part out of the way I changed the onload to get the fragment of the URI of the current document, interpret it as an XPath and highlight and navigate to the selected nodes. I also added an interactive floating bar from which you can enter your own XPaths and do the same. On a related note, I found that when accessing XML files via the file URI scheme the fragment is stripped off and not available to the javascript.

The next steps are of course to actually implement XPointer framework parsing as well as the limited number of schemes that the XPointer framework specifies.xml xpointer msxml res xpath xslt resource ie7 technical browser ie xsl

Opera Speed Dial Code-less Hack for IE7

2007 Apr 17, 11:45Opera (the fifth most popular web browser) has a new feature named Speed Dial (video of it in action). Whenever you open a new tab you get your Speed Dial view which consists of nine thumbnails of user-settable pages. Its like a quick-favorites that appears every time you open a new tab. I think this is a neat idea and was considering how I might do that in IE7. The following is my hack-y and ugly but no coding required version of Speed Dial for IE7. I like my hack and I'm about to expound upon it in unnecessary detail so skip to the last paragraph if you're afraid of losing interest.

By default in IE7, whenever you open a new tab you navigate to 'about:Tabs'. As noted in wikipedia the result of navigation to 'about:Tabs' is determined by values in the registry. Specifically, values in the key in "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\AboutURLs". Usually this fact is exploited by malicious software to hijack "about:blank" and show you ads but we can hijack it too in order to display our Speed Dial-ish page.

Of course since this is a code-less hack we've got limited options on what to change 'about:Tabs' to display. It should have the following requirements.

1. Something local so that our 'about:Tabs' doesn't disappear when we go offline and so that its relatively fast.
2. The user should be able to modify its content.
3. Show links that the user uses.
4. Show thumbnails of those links
5. Provide easy to use drag and drop interaction and generally look cool.

Now, I use del.icio.us which allows me to store all of my favorites online and which provides RSS feeds that list my saved links. New in IE7 is an RSS platform that will, among other things, cache RSS feeds locally. So, by pointing about:Tabs to my del.icio.us feed 'http://del.icio.us/rss/sequelguy/quickreference' I get (1) from IE7's RSS support, and (2) and (3) from del.icio.us. Of course requirements (4) and (5) are missing but hey, I said this was ugly.

In summary, if you change the registry value "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\AboutURLs!Tabs" to point to an RSS feed of your favorites you can get a hack-y version of Opera's Speed Dial. I should note that although its referenced on pages such as wikipedia changing your 'about:Tabs' URI in the manner I describe is not documented and not supported by Microsoft. There could be all kinds of horrible repercussions from this change of which I'm not aware. Yeah, actually you know what? Forget I said any of this. Pretend I never wrote it...browser technical hack