Date Published: 1999-08-01

Prologue

In one of my previous articles, we clarified that CGI is not Perl. That primary building block completed, we can continue onto discovering the basics of perl, the programming language of choice for cgi programs. Please remember, in this series of articles, we are building a knowledge base from the ground up. Each future article will expand and build on previous articles to help you gain a working knowledge of PERL. This series is not intended to teach you how to program in perl.

However, if you do wish to learn how to create your own perl programs, we invite you to review some of the many perl books for sale.

As you may be aware, Perl is a very robust programming language. It is considered an interpreted programming language, which means that the program is run in line-by-line order, from top to bottom.

The most widely distributed Perl code is always in a text-only format, meaning you can use any text editor to view or edit it. This allows you to edit perl programs to your liking. All you need to know to start customizing code is a few simple basics.*

In this article, we will discuss variables, arrays, hashes (associative arrays) and subroutines, the most common building blocks of all perl programs.

* Please be sure to read the EULA (End User License Agreement) that comes with the program you wish to customize. Many programmers require that in order for you to use the program, that the code must not be altered in any way. In most cases, if you choose to customize the program, you will not be eligible for support for the product anymore. Be sure you understand the copyrights and support policies of the programmer.

There are many reasons for wanting to learn the basics of perl without getting completely engrossed with learning how to develop your own programming languages.

Top 3 Reasons for Learning Perl Basics

1. Save money on customizations.
   If you've already purchased or downloaded perl cgi programs and installed them on your website, you know that you're sometimes limited with how the program will look. How many times do you wish you knew how to make those little changes that would make the program seem like a part of your web site, and not an afterthought? What about the typos (horror!) that sometimes the programmers overlook? But when you open the program in your text editor, you cringe, whine, whimper, close the file and hope your visitors don't blame you. (Of course, if you mention typos to programmers, they will correct them as quickly as possible.)
   Most programmers offer customization services for a fee, usually with a minimum charge of one hour. We've seen these customization rates for as little as free to upwards of $200/hr. Free "customizations" are typically not specific to your web site, and will be included in the next release of the program.
   But what if you just wanted to change the background, font or wording a little? Is it worth money or time to you? If not, this series will help guide you with the simple modifications you can make without incurring costs.
2. Save time
   As mentioned before, programmers are often available for customizations. But often they are inundated with projects, and cannot get to your customizations for some time. Some even say they cannot perform any customizations whatsoever.
   Also, the more you know, you will be less likely you will be to cause errors, and you'll be able to quickly locate the possible source of an error should one occur.
3. Expand your Comfort Zone
   It's a fact, the more you know about any subject, and the more you practice with it, not only will your skills increase, but your comfort level will, too. Even if you're primarily a webmaster, the time will come when you'll need to add interaction with your web site (feedback forms, guestbooks, etc.). You're probably doing those things already if you're reading this article.
   The first few times you install a perl program, you may fumble along (a completely normal thing), pull out your hair, and hesitate every step of the way. Knowing about perl basics will greatly assist you in quickly and effectively installing perl programs.