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Current Berkman People and Projects

2009 Jul 20, 5:06Berkman Center aggregate blog of its members and activies.PermalinkCommentsberkman harvard legal blog feed technical

Common Web Server software comparison report

2009 Jul 1, 2:24Stats on HTTP servers and HTTP server response headers. "Current statistics are based on a sample of 84604 probed servers, gathered in the last 386 days."PermalinkCommentshttp statistics server internet http-header via:mnot technical

Bits Up!: DNS Prefetching for Firefox

2009 Jun 22, 3:28Details on Firefox's DNS prefetching: "The Firefox implementation takes this approach one step further than just pre-resolving anchor href hostnames. It uses the prefetch logic on URLs that are being included in the current document. By this I mean that it uses the prefetch logic on things like images, css, and jscript that are being loaded right away, in addition to anchor links which might be clicked on at a slightly later time."PermalinkCommentsdns dns-prefetching html performance networking firefox mozilla technical

InfoQ: HTTP Status Report

2009 Apr 29, 12:34"In this presentation, recorded at QCon San Francisco 2008, HTTPbis WG chair Mark Nottingham gives an update on the current status of the HTTP protocol in the wild, and the ongoing work to clarify the HTTP specification."PermalinkCommentshttp httpbis protocol ietf reference video authentication cookie uri url tcp sctp mark-nottingham via:ericlaw

Thoughts on registerProtocolHandler in HTML 5

2009 Apr 7, 9:02

I'm a big fan of the concept of registerProtocolHandler in HTML 5 and in FireFox 3, but not quite the implementation. From a high level, it allows web apps to register themselves as handlers of an URL scheme so for (the canonical) example, GMail can register for the mailto URL scheme. I like the concept:

However, the way its currently spec'ed out I don't like the following: PermalinkCommentsurl template registerprotocolhandler firefox technical url scheme protocol boring html5 uri urn

Achron - Time Travel is Coming

2009 Apr 1, 1:22Is it still a _real-time_ strategy game if you travel through time? "If another player is attempting to adversely change the past, players will sometimes keep racing back to out-undo each other. Anything that must travel back in time in order to maintain the current state of causality is denoted to the player, which helps manage paradoxes."PermalinkCommentsvideo videogame time-travel strategy rts game

Outline View Internet Explorer Extension

2009 Mar 23, 8:13

I've made another extension for IE8, Outline View, which gives you a side bar in IE that displays an outline of the current page and lets you make intrapage bookmarks.

The outline is generated based on the heading tags in the document (e.g. h1, h2, etc), kind of like what W3C's Semantic data extractor tool displays for an outline. So if the page doesn't use heading tags the way the HTML spec intended or just sticks img tags in them, then the outline doesn't look so hot. On a page that does use headings as intended though it looks really good. For instance a section from the HTML 4 spec shows up quite nicely and I find its actually useful to be able to jump around to the different sections. Actually, I've been surprised going to various blogs how well the outline view is actually working -- I thought a lot more webdevs would be abusing their heading tags.

I've also added intrapage bookmarks. When you make a text selection and clear it, that selected text is added as a temporary intrapage bookmark which shows up in the correct place in the outline. You can navigate to the bookmark or right click to make it permanent. Right now I'm storing the permanent intrapage bookmarks in IE8's new per-domain DOM storage because I wanted to avoid writing code to synchronize a cross process store of bookmarks, it allowed me to play with the DOM storage a bit, and the bookmarks will get cleared appropriately when the user clears their history via the control panel.

PermalinkCommentstechnical intrapage bookmark boring html ie8 ie extension

Tab Expansion in PowerShell

2008 Nov 18, 6:38

PowerShell gives us a real CLI for Windows based around .Net stuff. I don't like the creation of a new shell language but I suppose it makes sense given that they want something C# like but not C# exactly since that's much to verbose and strict for a CLI. One of the functions you can override is the TabExpansion function which is used when you tab complete commands. I really like this and so I've added on to the standard implementation to support replacing a variable name with its value, tab completion of available commands, previous command history, and drive names (there not restricted to just one letter in PS).

Learning the new language was a bit of a chore but MSDN helped. A couple of things to note, a statement that has a return value that you don't do anything with is implicitly the return value for the current function. That's why there's no explicit return's in my TabExpansion function. Also, if you're TabExpansion function fails or returns nothing then the builtin TabExpansion function runs which does just filenames. This is why you can see that the standard TabExpansion function doesn't handle normal filenames: it does extra stuff (like method and property completion on variables that represent .Net objects) but if there's no fancy extra stuff to be done it lets the builtin one take a crack.

Here's my TabExpansion function. Probably has bugs, so watch out!


function EscapePath([string] $path, [string] $original)
{
    if ($path.Contains(' ') -and !$original.Contains(' '))
    {
        '"'   $path   '"';
    }
    else
    {
        $path;
    }
}

function PathRelativeTo($pathDest, $pathCurrent)
{
    if ($pathDest.PSParentPath.ToString().EndsWith($pathCurrent.Path))
    {
        '.\'   $pathDest.name;
    }
    else
    {
        $pathDest.FullName;
    }
}

#  This is the default function to use for tab expansion. It handles simple
# member expansion on variables, variable name expansion and parameter completion
# on commands. It doesn't understand strings so strings containing ; | ( or { may
# cause expansion to fail.

function TabExpansion($line, $lastWord)
{
    switch -regex ($lastWord)
    {
         # Handle property and method expansion...
         '(^.*)(\$(\w|\.) )\.(\w*)$' {
             $method = [Management.Automation.PSMemberTypes] `
                 'Method,CodeMethod,ScriptMethod,ParameterizedProperty'
             $base = $matches[1]
             $expression = $matches[2]
             Invoke-Expression ('$val='   $expression)
             $pat = $matches[4]   '*'
             Get-Member -inputobject $val $pat | sort membertype,name |
                 where { $_.name -notmatch '^[gs]et_'} |
                 foreach {
                     if ($_.MemberType -band $method)
                     {
                         # Return a method...
                         $base   $expression   '.'   $_.name   '('
                     }
                     else {
                         # Return a property...
                         $base   $expression   '.'   $_.name
                     }
                 }
             break;
          }

         # Handle variable name expansion...
         '(^.*\$)([\w\:]*)$' {
             $prefix = $matches[1]
             $varName = $matches[2]
             foreach ($v in Get-Childitem ('variable:'   $varName   '*'))
             {
                 if ($v.name -eq $varName)
                 {
                     $v.value
                 }
                 else
                 {
                    $prefix   $v.name
                 }
             }
             break;
         }

         # Do completion on parameters...
         '^-([\w0-9]*)' {
             $pat = $matches[1]   '*'

             # extract the command name from the string
             # first split the string into statements and pipeline elements
             # This doesn't handle strings however.
             $cmdlet = [regex]::Split($line, '[|;]')[-1]

             #  Extract the trailing unclosed block e.g. ls | foreach { cp
             if ($cmdlet -match '\{([^\{\}]*)$')
             {
                 $cmdlet = $matches[1]
             }

             # Extract the longest unclosed parenthetical expression...
             if ($cmdlet -match '\(([^()]*)$')
             {
                 $cmdlet = $matches[1]
             }

             # take the first space separated token of the remaining string
             # as the command to look up. Trim any leading or trailing spaces
             # so you don't get leading empty elements.
             $cmdlet = $cmdlet.Trim().Split()[0]

             # now get the info object for it...
             $cmdlet = @(Get-Command -type 'cmdlet,alias' $cmdlet)[0]

             # loop resolving aliases...
             while ($cmdlet.CommandType -eq 'alias') {
                 $cmdlet = @(Get-Command -type 'cmdlet,alias' $cmdlet.Definition)[0]
             }

             # expand the parameter sets and emit the matching elements
             foreach ($n in $cmdlet.ParameterSets | Select-Object -expand parameters)
             {
                 $n = $n.name
                 if ($n -like $pat) { '-'   $n }
             }
             break;
         }

         default {
             $varNameStar = $lastWord   '*';

             foreach ($n in @(Get-Childitem $varNameStar))
             {
                 $name = PathRelativeTo ($n) ($PWD);

                 if ($n.PSIsContainer)
                 {
                     EscapePath ($name   '\') ($lastWord);
                 }
                 else
                 {
                     EscapePath ($name) ($lastWord);
                 }
             }

             if (!$varNameStar.Contains('\'))
             {
                foreach ($n in @(Get-Command $varNameStar))
                {
                    if ($n.CommandType.ToString().Equals('Application'))
                    {
                       foreach ($ext in @((cat Env:PathExt).Split(';')))
                       {
                          if ($n.Path.ToString().ToLower().EndsWith(($ext).ToString().ToLower()))
                          {
                              EscapePath($n.Path) ($lastWord);
                          }
                       }
                    }
                    else
                    {
                        EscapePath($n.Name) ($lastWord);
                    }
                }

                foreach ($n in @(Get-psdrive $varNameStar))
                {
                    EscapePath($n.name   ":") ($lastWord);
                }
             }

             foreach ($n in @(Get-History))
             {
                 if ($n.CommandLine.StartsWith($line) -and $n.CommandLine -ne $line)
                 {
                     $lastWord   $n.CommandLine.Substring($line.Length);
                 }
             }

             # Add the original string to the end of the expansion list.
             $lastWord;

             break;
         }
    }
}

PermalinkCommentscli technical tabexpansion powershell

G1 Android Phone

2008 Nov 9, 11:29

T-Mobile G1 Wallpapers by romainguy
I finally replaced my old regular cell-phone which was literally being held together by a rubber band with a fancy new G1, my first Internet accessible phone.

I had to call the T-Mobile support line to get data added to my plan and the person helping me was disconcertingly friendly. She asked about my weekend plans and so I felt compelled to ask her the same. Her plans involved replacing her video card so she could get back to World of Warcraft and do I enjoy computer gaming? I couldn't tell if she was genuine or if she was signing me up for magazines.

I was with Sarah in her new car, trying out the phone's GPS functionality via Google Maps while she drove. I switched to Street View and happened to find my car. It was a weird feeling, kind of like those Google conspiracy videos.

The phone runs Google's open source OS and I really enjoy the application API. Its all in Java and URIs and mime-types are sort of basics. Rather than invoking the builtin item picker control directly you invoke an 'intent' specifying the URI of your list of items, a mime-type describing the type of items in the list, and an action 'PICK' and whatever is registered as the picker on the system pops up and lets the user pick from that list. The same goes if you want to 'EDIT' an image, or 'VIEW' an mp3.

I wanted to replace the Google search box gadget that appears on the home screen with my own search box widget that uses OpenSearch descriptors but apparently in the current API you can't make home screen gadgets without changing parts of the OS. My other desired application is something to replace this GPS photo tracker device by recording my location to a file and an additional program on my computer to apply those locations to photos.

PermalinkCommentstmobile personal api phone technical g1 android google

THOMAS Publishes Permanent Links (Another Recommendation Realized) | The Open House Project

2008 Oct 10, 3:35Apparently thanks to the Open House Project, US legislation can now have real and permanent links. I'm kind of surprised that legislation would exist so freely on the Internet without real links. The Open House Project is "a collaborative effort by government and legislative information experts, congressional staff, non-profit organizers and bloggers to study how the House of Representatives currently integrates the Internet into its operations, and to suggest attainable reforms to promote public access to its work and members."PermalinkCommentsinternet url link uri politics

Internet Explorer Makes Desperate Overture To Become Default Browser | The Onion - America's Finest News Source

2008 Sep 29, 2:28'"Internet Explorer is not currently your default browser. Would you like to make it your default browser?" the software program asked in an attempt to guilt Drewing into accepting its offer out of pure pity.'PermalinkCommentsonion humor browser ie microsoft

13 things that do not make sense - space - 19 March 2005 - New Scientist Space

2008 Aug 14, 3:59"13 things that do not make sense, Updated 11:22 19 December 2007, From New Scientist Print Edition. Michael Brooks". Thirteen mysteries of physics and biology currently under contention.PermalinkCommentsscience article michael-brooks biology physics

VERTIGO

2008 Aug 14, 9:25"When a savage creature known only as the Adversary conquered the fabled lands of legends and fairy tales, all of the infamous inhabitants of folklore were forced into exile. Disguised among the normal citizens of modern-day New York, these magical characters have created their own peaceful and secret society within an exclusive luxury apartment building called Fabletown. But when Snow White's party-girl sister, Rose Red, is apparently murdered, it is up to Fabletown's sheriff, a reformed and pardoned Big Bad Wolf, to determine if the killer is Bluebeard, Rose's ex-lover and notorious wife killer, or Jack, her current live-in boyfriend and former beanstalk-climber."PermalinkCommentscomic read download free via:boingboing fiction

New Cookie related Internet Drafts from Yngve N. Pettersen on 2006-03-20 (ietf-http-wg@w3.org from January to March 2006)

2008 Jun 30, 3:46Opera's solution to minimal security domain determination: "The drafts describe 1) Opera's current "rule of thumb" implementation that uses DNS in an attempt to confirm the validity of a domain, and 2) a proposed new HTTP based lookup service that returPermalinkCommentsopera rfc ietf cookie http internet browser dns domain

Generating N-D Tetris Pieces

2008 Jun 1, 7:27

When I woke up this morning for some reason I was thinking about Polytope Tetris, my N-D Tetris game, and specifically generating Tetris pieces in various number of dimensions. When I first wrote PTT I thought that as the number of dimensions increased you could end up with an infinite number of non-equivalent crazy Tetris pieces. However this morning I realized that because you only get four blocks per piece there are only a possible three joints in a single Tetris piece which means that you only need three dimensions to represent all possible distinct N-D Tetris pieces.

Below is the table of the various possible pieces per number of dimensions and sorted by the number of joints in the piece. Notice that the 'J' and 'L' become equivalent in 3D because you can rotate the 'J' through the third dimension to make it an 'L'. The same happens for 'S' and 'Z' in 3D, and 'S+' and 'Z+' in 4D.

Joints Name 1D 2D 3D +
1 I I I I I
2 J J J J
L L
3 O O O O
T T T T
S S S S
Z Z
T+ T+ T+
S+ S+ S+
Z+ Z+
Total 1 7 8 7

As a consequence of not realizing there's a finite and small number of N-D Tetris pieces, I wrote code that would randomly generate pieces for a specified number of dimensions by wandering through Tetris space. This consists of first marking the current spot, then randomly picking a direction (a dimension and either forward or backward), going in that direction until hitting a previously unvisited spot and repeating until four spots are marked, forming a Tetris piece. However this morning I realized that continuing in the same direction until reaching am unvisited spot means I can't generate the 'T+' piece. I think the better way to go is keep the list of all possible pieces, pick one randomly, and rotate it randomly through the available dimensions. Doing this will also allow me to give distinct pieces their own specific color (like the classic Tetris games do) rather than picking the color randomly like I do now.

PermalinkCommentspolytope tetris tetris

Lifeboat Foundation Bios: Joshua W. Klein, M.S.

2008 May 16, 2:33This guy works on interesting projects. "Joshua W. Klein, M.S. is a Mobile, Personal, and Future Technology Specialist who is currently Senior Technology Principal at Frog Design."PermalinkCommentsjoshua-klien bio

Homemade GPS jammers raise concerns

2008 Apr 22, 4:33Reaction to Phrack's howto on GPS jammer. Sounds like the article wants to make it into a bigger issue than it is: "Information in the article that appears in the current issue of the online hacker magazine Phrack potentially puts at risk GPS devices usePermalinkCommentsgps gps-jamming phrack government

Cory Doctorow's craphound.com - Podcast

2008 Mar 28, 1:37Cory Doctorow regularly reads from his books and irregularly includes random other stuff. Currently reading the novella he co-wrote with Ben Rosenbaum, 'True Names'.PermalinkCommentscory-doctorow creativecommons boingboing book fiction podcast scifi

Now using NearlyFreeSpeech.NET to host deletethis.net

2008 Mar 17, 1:25

I've switched from using my own home web server of which one of the harddrives died, to using NearlyFreeSpeech.NET, an actual real live web hosting service. So far I'm very happy with them and they give me almost exactly what I had on my own home server: ssh access, vim, php, java, etc. etc. The only notable things they don't do are (1) cron jobs which I use currently and (2) SSL which I don't use currently. I can replace my cron job usage and I suppose I'll have to reevaluate my web hosting if I ever need SSL. At the moment many of the server side things like Vizicious will be unavailable. I'll work on getting those working again at some point.

PermalinkCommentstechnical webhosting webserver server homepage

Mathematics for the President and Congress

2008 Mar 9, 1:17"It is, quite frankly, one of the best critiques of current K-12 mathematics education I have ever seen. Written by a first-class research mathematician who elected to devote his teaching career to K-12 education."PermalinkCommentsvia:ethan_t_hein math education paper
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