Welcome to Perl Critic

Perlcritic.org is a website with focus on the PERL language and other types of scripting and programming languages.

What is PERL

Perl is short for Practical Extraction and Reporting Language, and is basically an interpreted programming language.
Perl can be used for quite a lot of things and it comes with a huge amount of premade libraries and resources. It’s one of the most popular software languages on the Internet today since it can be used for so many different things.

Where can you get Perl?

Most webhosts and servers running some variant of Linux already come with Perl installed by default. If you are setting up your own Linux system and want to take advantages perl you can goto their official website and click on the download link there. Then find the version that match your OS and download the binary package for it, upload it to your own server and install it. It’s really easy to install and on most types of OS, it only takes a few minutes before everything are up and running.

Who created Perl?

Practical Extraction and Reporting Language was created around 1987 by Larry Wall and was ment to be a general purpose unix scripting programming language aimed at making some of Larry’s work more simple. It has sense then improved and grown quite a bit and is now one of the most used scripting languages on the Internet. The latest version today is Perl 6.

How can I tell if it’s installed?

It’s actually quite simple to see if you got perl installed on your Linux system. Simple open a command prompt on your computer or server and type the command perl -v which will show you the perl version installed if it’s installed, otherwise this command will return an error and you will need to download and install it.

Where to find Perl libraries?

There are a lot of premade perl libraries and modules for you to use and this is also one of the main reasons who so many like PERL as you don’t have to write everything from scratch as most tasks you can think of have already been implemented in a module or library. A good place to start searching for Perl libraries and modules would be on CPAN – the Comprehensive Perl Archive Network – goto CPAN here

What is Perl::Critic

Perl::Critic is a static code analysis system, based on the PPI parsing library, that you can use with the Perl scripting language. It is available as a source-code distribution on the Comprehensive Perl Archive Network CPAN. The commandline tool – perlcritic can check various Perl source code files and give you a report on the code quality and let you choose from a bunch of policies to check the different Perl programming styles.

A few examples of live use of PERL

Here a few examples of live websites which have implemented perl in their design and using it add more functions or features to their websites or to give the customers a better use experience.

Kvali Vinduer

www.kvalivinduer.dk is an online webshop selling all types of windows such as Dannebrogsvinduer træ, Bondehusvinduer alu and Topstyret vinduer. When buying a window here you need to costumize it to your needs, this advanced customization form is written in the server side script perl combined with some javascript. See the script in action here at Kvali Vinduer

JK Network Videoovervåging

www.jknetwork.dk is a company selling a surveillance system called videoovervågning to home owners and shop owners. Their new website has some features that helps you to pick the best video overvågning system for your needs by filling out a step by step form that is of course written in our favorite server side scripting language. Take a look here at JK Network Videoovervåging

karnevalsshoppen kostumer and udklædning

Karnevalsshoppen.dk sells all kinds of costumes and dresses for events such as Halloween, Oktoberfest and Fastelavn. Some of their more advanced filter options for picking the best kostume is written in perl in order to get the speed needed. They had a PHP version to begin with but it simple wasn’t fast enough with their huge product database with different types of udklædning and kostumer. See how it works on Karnevalsshoppen Udklædning

Kvalibrænde brænde and briketter

kvalibrænde.dk is a shop selling brænde and briketter in high quality. It’s run by my friends father and I am including this in the list as I have helped optimize the site with some script optimizations, in order to pick the right product selections for their products briketter, træbriketter and brænde in the boxes, since the prices are depending on where you live in the country. You can see how it’s done at kvali Brænde

Nyt tag from gratistagtjek

Gratistagtjek.dk is an information site on roofs and roofing tips. They have tons of info on things like nyt tag, skifertag, tegltag, ståltag etc. Just like the site Kvali Brænde they needed some optimizations, so recently I made a calculator in Perl for their site where people can enter some information about their house and the calculator will return the price of a new roof for such a house. After implementing their nyt tag calculator their site became much more popular. See how it works here at gratistagtjek.dk – Nyt tag

Of course there are many more uses for this programming language, and I will within the next month be adding a selection of solutions to common problems that can be solved by using Perl, PHP, CGI or other types of scriping languages.