How to set permissions for Linux personal web site

Let's suppose that we have a user account located at ~ and a web site at ~/www

We need to set the directory permissions to 755 allow every

We need to set the files to 644 (owner can r/w, everybody else can r)

    u g w
0 - 0 0 0
1 - 0 0 1
2 - 0 1 0
3 - 0 1 1
4 - 1 0 0
5 - 1 0 1
6 - 1 1 0
7 - 1 1 1

u stands for 'user', g for 'group' and w for 'world'.
These are the classic Unix file permissions.

However, if AFS is being used, we also need to provide permissions in the access control lists (ACL).

The following command gives access to the web folder to anyone:

fs sa www system:anyuser rl

The following lists the existing permissions:

fs la www

More help on AFS
"
There are seven standard AFS permissions, each referred to by one of the letters r, l, i, d, w, k and a. The lida permissions apply to directories and the rwk permissions apply to files.
Directory permissions

l (lookup)
Allows one to list the contents of a directory. It does not allow the reading of files.
i (insert)
Allows one to create new files in a directory or copy new files to a directory.
d (delete)
Allows one to remove files and sub-directories from a directory.
a (administer)
Allows one to change a directory's ACL. The owner of a directory can always change the ACL of a directory that s/he owns, along with the ACLs of any subdirectories in that directory.

File permissions

r (read)
Allows one to read the contents of file in the directory.
w (write)
Allows one to modify the contents of files in a directory and use chmod on them.
k (lock)
Allows programs to lock files in a directory.

"

Estonia First Graders will learn Web Coding

Estonia Reprograms First Graders as Web Coders | Wired Enterprise | Wired.com: Public schools in Estonia will soon have a curriculum for teaching web and mobile application development to students as early as first grade.

According to an article published by UbuntuLife, the program begins this month with training for primary-school teachers. This will be followed by pilot programs. Eventually, the curriculum will be available to all public schools, with educational materials for all levels from grades 1 through 12.

(...)

Back in May, Mozilla executive director Mark Surman told Wired that kids start deciding whether to be content makers or mere consumers sometime around the age of 8 to 10 years old. “If we want kids to be makers rather than consumers (our goal), this is a critical age,” he said.

How to bookmark all open tabs in Firefox

Press Ctrl+Shift+D or go to Bookmarks and select "Bookmark all Tabs". This will save all the open tabs into one folder and you can resume surfing the next day by select "Open All in Tabs" from the bookmark folder.

Bonus Tip: Name this folder something like "Feb25" or "022508" so it becomes easy for you to guess the date from the folder name itself.

Source: http://www.labnol.org/software/browsers/save-all-open-websites-firefox-tabs-sessions-quit/2382/

Internet time machine

A team of computer scientists at the Los Alamos Research Library in New Mexico and Old Dominion University (ODU) in Virginia has written a technical specification that embeds the concept of time into Internet applications. The specification is part of the team’s proposed information framework, known as Memento, which creates an application that allows the version control of Web pages, databases and other online information sources.

Source: Government Computer News via ACM Tech News

Beware of Greyhound's search bug

I have traveled with Greyhound in the United States for a few times and I think they provide a very useful and cost effective service.

Recently I tried to book a trip from (Rochester, NY) to (New York, NY) departing on a specific date: April 20th.

I filled in the search form as expected and pressed the search button:

Notice the departure date: April 20th.

A set of schedules were presented, similar to the following screenshot.
I picked the hour I preferred, proceeded to the next steps and purchased the ticket.

Notice the small date in the results... April 19th!

So far so good, right? No! :(

When I printed the tickets I realized the departure date was not April 20th as I had asked for, but April 19th! I went back to the site and checked if the mistake had been mine or not. There was indeed a bug in the web site's search.

Should I have double-checked the date before paying? Sure.

Should Greyhound's web site behave like this? Surely not!

I immediately contacted customer service and they replied a couple of days later, saying that I had bought a Non refundable Print at Home ticket, and that they I would not be able to change your departure date...

I was very disappointed, because I immediately contacted them after the mistake, and the error was induced by the web site's bug.

As it appears that there is nothing else I can do to change the ticket date, I decided to blog about this bad customer experience in the hope that Greyhound will fix their web site and avoid having more sad customers like me...

If you have had similar experiences, please feel free to share them in the comments. I appreciate your sympathy.

Download videos from YouTube

ClipNabber provides links to download videos from YouTube and other similar sites.

Google tips for webpage design

Here are four design tips from Google to pay attention to:

Tip #1: Pass the 8 second test. At first glance, a visitor should understand the purpose of your website within a few seconds. People are busy and have limited attention spans — you want to keep them from hitting the dreaded back button.

Tip #2: Tell them what's in it for them. Create clear and tangible benefits (e.g., "Save more! Make extra money! Look better with our product!").

Tip #3: Use compelling images. Try product images instead of generic stock photos, icons with blocks of text, and buttons instead of links. Keep in mind that a low-quality, irrelevant image can kill your site's credibility.

Tip #4: Close the sale. Help your visitors take the next step. Make that step clear and easy to reach; don't make them hunt for it. Action words like "buy now" may work better than "add to cart," for instance.

Originally posted on the Google Blog.

Tomcats

Sometimes, one "cat" is not enough... ;-)


I've just finished the support for creation multiple replicas of Apache Tomcat web servers.

It will be part of the next stage in the Distributed Systems course. More details will emerge soon, after the project requirements document is published.

9 uses for Twitter

Twitter is a very useful new web tool. You can request to follow me on .



If you want to know more about the service, read John C Dvorak's article Nine Ways to Use Twitter:
Microblogging
1. Twitter Witness = Twitness
2. Breaking News
3. Communication
4. Feedback
5. Crowd-sourcing
6. Informal Polling
7. Public Address System
8. Sales and Marketing
9. Tweet Ups

The evolution of the Web

The current day Internet is the global network that connects people from all over the world and enables them to meet to work and have fun together.

At the center of the enormous growth of Internet use in 1990s was a new application: the World Wide Web. The Web leveraged the existing Internet infrastructure and protocols TCP/IP and and provided a simple and elegant abstraction: "Everything is a resource; Any resource can link to other resources".

The Web has evolved from its origins. We can summarize the evolution in three stages: the web of documents, the web of applications, and the web of users.

The web of documents was the original hypertext document system, built from HTML pages linking to other pages. The pages were initially static, but soon there were many ways technologies to generate dynamic pages.

The web of applications came next, leveraging the dynamic web page technologies. Some successful web applications examples are: e-commerce (e.g. Amazon.com), web mail (e.g. Hotmail), and customized portals (e.g. Yahoo!). Soon, the application providers realized that the user inputs were very useful to improve the web applications and its capabilities.

The web of users is the current stage in the Web development. It is also known by the moniker Web 2.0. The user inputs became central in the provided applications. Amazon's recommendations are an early example of this. More notably, the Google search engine took advantage of user clicks on results to create a PageRank. More recently, the user contributions are even more explicit, with social networking applications, like Facebook, MySpace, LinkedIn, Delicious, among many others.

So, what is next for the Web? It is about to become even more world wide.

There are three technology trends that will shape the next stage of the Web: mobile Internet access, geographic information systems, and automatic identification and sensing.

Mobile access to the Internet, using hand-held devices and wireless networks is on the rise.
People are starting to use the Web in new places and situations where a desktop or laptop computer would not be possible or convenient. As a result, there are new user needs and requirements.

Geographical information systems, like Google Maps, allow users to access map data with several information layers, to locate points of interest and provide directions. The current user location can be determined using a GPS enabling location-aware applications.

Automatic identification and sensing technologies, like RFID identifiers and sensors, are making their way to supply chains in retail, pharmaceutical, and other industries. Soon it will be possible to tag any valuable or interesting physical object, enabling item level track & trace. In addition, the object identity can be used as a search parameter, to retrieve data from the Web.

When these three technologies are combined, an Internet of Things emerges, a Web of Things, where people and the physical world can interact in novel ways.

As an example scenario consider the following. A person walks into a bookstore and finds an interesting book. However the only available copy has a torn page. Using the mobile phone camera, the user scans the book's bar-code and queries if the book is available in any other nearby bookstore. It isn't, so the user goes to a on-line shop and orders one copy to be delivered the next day at his home.

Can you imagine it? If you can, and would like to work on it, leave a comment here on the blog or email me.