answersy.com Blog

So far, Lee's Code Highlighter is the best I found. Download it at http://ideathinking.com/wiki/index.php/WordPress:CodeHighlighterPlugin

To install the plugin:

1. Unzip the plugin archive
2. Upload the directory to the /wp-content/plugins/ directory
3. Activate the plugin through the 'Plugins' menu in WordPress

It is useful to add a border on the code section. To achieve so, in your themes folder /wp-content/themes/yourTheme/

Add the following to your style.css

pre {
font-size: 12px;
background:#f8f8f8;
padding:4px;
border:#c96 1px dotted;
}

Sometimes we need to start a background process to do a long-running job, while the parent process may die before the child dies. To do so in Perl, you can use the following code:

#!/usr/bin/perl -w
use strict;
use POSIX qw(:sys_wait_h);
 
my $kidpid;
if (!defined($kidpid = fork())) {
# fork returned undef, so failed
die ("Failed to fork");
exit;
} elsif ($kidpid == 0) {
# fork returned 0, so this branch is child
exec("./longjob.pl");
exit;
} else {
# parent
$SIG{CHLD} = sub { 1 while ( waitpid(-1, WNOHANG)) > 0 };
print "Parent exited\\n";
exit;
}

If the parent is a web server process and writes back a html page, it might not return immediately. The solution is to close the STDIN, STDOUT, and STDERR in the child process.

#!/usr/bin/perl -w
use strict;
use POSIX qw(:sys_wait_h);
 
my $kidpid;
if (!defined($kidpid = fork())) {
# fork returned undef, so failed
die ("Failed to fork");
exit;
} elsif ($kidpid == 0) {
# fork returned 0, so this branch is child
close (STDIN);
close (STDOUT);
close (STDERR);
exec("./longjob.pl");
exit;
} else {
# parent
$SIG{CHLD} = sub { 1 while ( waitpid(-1, WNOHANG)) > 0 };
print "Parent exited\\n";
exit;
}

The demo can be found at http://answersy.com/ajax/widgetYCN.html. All you need is to copy the javascript code in the textarea and paste it on your page.

This version is implemented using iframe. I have a demo to use Ajax, but it will fail on other sites because XMLHttpRequest or ActiveXObject can only request data from the same domain. There is workaround, but not simple.

To implement UI widgets using javascript:

(1) include a piece of javascript code

(2) the code will do document.write("<iframe src = Service.html />");

Everybody starts to talk about web 3.0 now. If web 2.0 is Broadband + Ajax + UGC (User Generated Contents), 3.0 must be Mobile + UGA (User Generated Applications), which will eventually make the internet a giant computing power grid. Every device on the web will contribute to the grid, and most applications will run on part of the grid and deliver its result to somewhere else. With a mobile device carried in pocket, people will be able to do most of the daily jobs on the web wherever he is.

Computing utility companies will start to emerge, they will provide open computing resources so that everyone will be able to build his web services easily.

UGC lowered the barrier that people put data on the web, but not application or services. Nowadays, if you want to start a web services, you need to worry a lot of infrastructure issues, software component issues. For example, if you are a great blogger, and you want to sell some productions on your blog, it is not easy to quickly configure your site so that you can have ordering, bookkeeping and payment system. What if there are a lot of such web services and all you need is to drag and drop them on your site? What if everybody can customize and improve the web services if he wants to? What if when your business grows, all you need is to subscript to a better plan and you do not have to worry about data center and hardware? This is the future of the Web.

To achieve so, we need the following things ready:

(1) An open and expendable computing power grid
(2) Gigabyte bandwidth on wire and air
(3) Security

Use CGI package:

#!/usr/bin/perl -w
use strict;
use CGI qw/:standard/;
my $cgivars = new CGI;
my @names = $cgivars->param;
foreach (@names) {
print "$_ => ", $cgivars->param($_), "\\n";
}

See http://dev.mysql.com/doc/refman/4.1/en/bit-functions.html

http://dev.mysql.com/doc/refman/5.0/en/bit-functions.html

And the users' comments are very helpful!

SELECT
SUM(IF(rubrik & 1, 1, 0)) actus,
SUM(IF(rubrik & 2, 1, 0)) shopping,
SUM(IF(rubrik & 4, 1, 0)) utils,
SUM(IF(rubrik & 8, 1, 0)) communication,
SUM(IF(rubrik & 16, 1, 0)) services,
COUNT(user_id) AS total,
FROM preferences p

Use el.style.cursor = "pointer"; instead! It works for both IE and FF.

See also http://www.permadi.com/tutorial/cssCustomCursor/ for a more detailed explanation.

Sometimes we can hear from the news that astronomers have found a galaxy billions of light-years away. Had what was claimed been true, we are observing some stories of the universe that happened several billions years ago. Are we mixing history with the present?

If we discover some outer space civilizations, say a thousand light-years away from our planet, and want to contact them, are we saying that the communication has-two thousand-year round trip delay? If light speed is the upper limit that information can be passed on, unfortunately, this is true.

In very rare cases, human beings have the patience to wait for a message for more than several years, not to say thousands years. As a result, I don't feel space travel is feasible at all if we cannot find a way to beat this communication delay. We must be able to synchronize states in two different locations without significant transmission delay. Is this possible?

To achieve so, we have to think dimensions. If time is a dimension, the universe has all the historical and future states stored.

To be continued ...

Almaden Quicksilver County Park is located in south San Jose, in the town of New Almaden. From Interstate I-280 in Santa Clara, take CA 85 south. Exit at Almaden Expressway, make the first left, then the next right onto Almaden Expressway. Drive about 4 miles, then turn right onto Old Almaden Road. Drive on Old Almaden about 3.5 miles to the Hacienda Trailhead on the right side of the road. You can find more detailed rules at sccgov's site.

When we got to the trailhead, it was already 3:30PM. With bigleaf maples, and black and blue oaks shedding their colorful leaves, the park felt very quite. So, we decided to take it easy and enjoy the peace.

We first followed Mine Hill Trail. When we got to the first fork, we took the path to Hacienda Trail.

After heading downhill for a while, the trail starts to wind up to the top a small hill. From there, you can look over the nearby hills and downtown San Jose.

After about 1.5 miles, Hacienda Trail meets Virl O Norton Trail where we made a slight left turn and stayed on Hacienda.

Before Hacienda meets Capehorn Pass Trail, one can find a set of rocks of very unique texture. After about .2 mile, we came back to Mine Hill and hiked downhill to the parking lot.

There is a saying in Chinese, "If a mountain has spirit inside, even if it is not high, it can still be very elegant." This is exactly my feeling when I started the engine heading home. For sure, I will revisit here again. :−) With more than 34 miles of trails in the park, there must be lots of nice places to explore!

I do not mean to give a full review here, rather, I would like to point out a trend.

The real impact of World Wide Web started with HTML and NCSA's (National Center for Supercomputing Applications) browser Mosaic. Nowadays, many sites such as Flickr, blogs and wikis, YouTube, MySpace, Facebook boast themselves as "web 2.0," some even start to buzz 3.0.

In Web 1.0, we have personal communication services such as email, messenger. We've been overwhelmed by all kinds of portals, corporate and personal websites, web directories, search engines. We also have had online businesses such as shopping, auction, gaming, payment, marketing, etc. The basic technology supporting Web 1.0 is HTML, a text-based, weakly-structured, state-less markup language.

In Web 2.0, we talked about user generated contents, social networks, tagging, virtual reality games. We heard about RSS, subscription, topic extraction and clustering. By introducing "content match" to web search, keyword advertising becomes an successful business model. Contents were, are and will continue to be the vital of the web. In order to serve contents better to the audiences, one need meta information, either generated by algorithms or by human tagging. Web contents will be more and more meta-rich. This is like programming language, at the beginning, it has integer, float and string, but to represent a business concept better, you need structures, you need relations. As a result, many web applications stared to use XML as an interface, internally and externally. HTML certainly can handle meta data in an ad hoc way, but that will soon become a bottleneck.

Till now, most web applications still have data and processing methods separated. In my opinion, content should not only be the data stream it contains, but also the instructions on how to operate the data. This reminds me the object-oriented technology in programming. With OO, data and procedures are stored in one object. When you pass an object, you not only send the data, but also methods or interface to handle them.

The future of the web, at application layer, should be object-oriented. An object has data, meta-data (instructions on how to interpret the data), and methods (on how to handle the data). This is not just a change in the location where the instructions resides, this makes each object a self-contained piece of information.

Why is this so important?

Let me give an example, it seems the movie industry can be badly hurt if everybody starts to download movies and spread them on the web. However, if a movie is not only a piece of data, but also an object that can defines its behavior; when one copies it, it can destroy itself or make it's own quality deteriorated, then, copyright or ownership can be defined in the object and better protected.

An object can define ownership, behaviors, it will also allow different presentations with the same data. This will promote more people and business to open to the internet.

To be continued ...