Learning is an Art

What is Perl?Perl is a programming language referred as Practical Extraction and Reporting Language written by Larry Wall. It was written with a motto TMTOWTDI i.e.

There’s More Than One Way To Do It.

Perl Properties

• Interpreted Language
• “Object-Oriented”
• Cross-platform
• Extensible, rich set of libraries
• Used for Web Programming

What do you need?

• Active state Perl or any other standard Perl interpreter
• Any text editor such as notepad

You can download Perl installer from ActiveState download website, you will get a list of installers there, download installer for windows.

Install ActiveState Perl, it does not takes much, simply double click on msi installer file and it will guide you through the rest of installation process.

Now that your installation is over simply go to windows command prompt and do the following

You should get the result as below

If you get these lines on command prompt, it means that Perl is successfully installed on your machine.

My First program

Just open your favorite editor and type the following lines

Your hello world program is ready save it as “helloworld.pl” in any directory you feel like.

Go to command prompt and change the current directory to directory where you have saved your “helloworld.pl” and type on command line

You will get output as:

Key things to notice:

• Everything that starts with a hash is a comment in perl
• Perl statement ends with a semicolon

Perl is a lot more than this hello world program, this was just to give you taste of Perl.

I will be back soon with more elaborate articles on Perl, please keep checking this place.

What is WebDAV

WebDAV stands for “Web-based Distributed Authoring and Versioning”. It is a set of extensions to the HTTP protocol which allows users to collaboratively edit and manage files on remote web servers. The tragedy, though, is that despite the acronym, the RFC specification doesn’t actually describe any sort of version control. Basic WebDAV clients and servers assume only one version of each file or directory exists, and can be repeatedly overwritten.

It was only few years, later RFC 3253 added versioning concepts to WebDAV, placing ‘V’ back in DAV, hence the term DeltaV. WebDAV/DeltaV clients and servers are often called just “DeltaV” programs, since DeltaV implies the existence of basic WebDAV.

Original WebDAV standard has been widely successful. Every modern computer operating system has a general WebDAV client built-in, and a number of popular standalone applications are also able to speak WebDAV — Microsoft Office, Dreamweaver, and Photoshop to name a few. On the server end, the Apache webserver has been able to provide WebDAV services since 1998 and is considered the de-facto open-source standard. There are several other commercial WebDAV servers available, including Microsoft’s own IIS.

DeltaV has not been so successful; it’s very difficult to find any DeltaV clients or servers. The few that do exist are relatively unknown commercial products.

Subversion client is not a fully-implemented DeltaV client. It needs certain types of things from the server that DeltaV itself cannot provide, and thus is largely dependent on a number of Subversion-specific HTTP REPORT requests that only mod_dav_svn understands. And also mod_dav_svn is not a fully-realized DeltaV server. Many portions of the DeltaV specification were irrelevant to Subversion, and thus left unimplemented.

Autoversioning

Though Subversion is neither a full DeltaV client nor the Subversion server a full DeltaV server, there is silver lining known as Autoversioning.
Autoversioning is an optional feature which is defined in the DeltaV standard. A typical DeltaV server will reject a WebDAV client attempting to do PUT to a file that’s under version control. To change a version-controlled file, the server expects a series proper versioning requests: something like MKACTIVITY,CHECKOUT, PUT, CHECKIN. But if the DeltaV server supports Autoversioning, then write-requests from basic WebDAV clients are accepted. The server behaves as if the client had issued the proper series of versioning requests, performing a commit under the hood. In other words, it allows a DeltaV server to interoperate with ordinary WebDAV clients that don’t understand versioning.

To activate autoversioning, you will need to add directive known as SVNAutoversioning in Apache httpd.conf file and set it as on.

When SVNAutoversioning is on, all write request to from WebDAV clients result in automatic commits. A generic log message is auto-generated and attached to each revision.

For reference on how to set up Subversion repository as network share drive using Windows Web-folders please read Using Subversion Repository as WebShare.

References:

• Subversion Documentation
• http://www.webdav.org/

In this article I am going to share my observation on a search engine scour.com; which claims to be a social search engine.

I would like to randomly point out few of my observations

• They are try to give a new face to search introducing socialization in searching; instead of reading full clicking on link and reading whole thing I can read comment from fellow users; provided some body has already commented on th result, but again this can easily be spammed with useless and misleading comments I really don’t know how they are going to handle that.
• The search is cumulative of results from scour, msn, yahoo, google that possibly could give you good results but what I got was not always useful; but still it is a good feature to see in place. But I would like to know what they are doing with all these results before displaying it and how they are claiming that result is optimum.
• If you type a string which does not give any result on any of the search engines it goes into unknown state and even does not tell you whats wrong; it keeps on displaying searching; I have reported this to them but no response.
• Time taken for search is higher than any other search engine but that should be expected as it searching three search engines and giving you the results but magnitude is higher than what is expectable; the search which took Google 0.06 seconds scour took around 2.13 seconds and as we say time is money a lot of money is getting lost out there.
• Worst part for me is that while browsing a result you can not find out what page of the site you are as you get a constant link like this http://scour.com/view/result/?URL=http://www.python.org/ this will remain like this what ever page you navigate; this has a reason behind it to enable you to vote and comment on the result but from usability point of view its not good.
• They are trying to buy publicity and attention; they have some point system for different actions like searching, commenting on search results, voting on search results and if you are able to reach 6500 points you get $25 visa gift card; I even read some one complaining of being banned when he was about to reach the mark; this raises some fingers on credibility of the company but I will leave it on company to answer that.

I would like to conclude with a thumbs up to them for the idea but idea can only become great if it can be implemented properly. You can not get success and publicity just by throwing some dollars here and there.