Learn to use CGI in Two Hours

Increase Traffic by Creating New Services With Perl/CGI - In as little as two hours you can be installing, writing and editing your own cgi scripts to handle mailing lists, order processing, feedback forms, discussion forums, links pages, password protected pages, membership databases and other web marketing \'must-have\' facilities.

About the author
I've been using the Internet since 1993. I opened my first Web site in
1998. I've taught myself HTML, CGI, Perl and SQL. I am *not* an expert
by any means. However, I have written Perl scripts to solve problems for
myself, my clients and my friends. I hope that much of what I've learned
will help you to master the art of writing, installing and using CGI scripts
more easily (and faster) than I did.
Purpose of this book
This book is intended to teach you how to obtain (or write) and install CGI
scripts written in Perl or other programming languages. The focus is
mainly on scripting in Perl, but the installation process is very much the
same for CGI scripts written in any other language.
By providing you with some complete scripts, some subroutines and the
tools for combining them in new ways, I hope to teach you a
"mix−and−match" approach to solving scripting tasks. I believe that if you
follow the principles taught here, you can be installing CGI scripts on your
Web server/site in a very short time.
Friends, this is not rocket science! It's simply a skill you have not yet
acquired. There was a time (come on...admit it) when you didn't even
know how to "surf the Web". You mastered that easily enough, didn't you?
You can pick this up almost as easily. Once you've got it, you'll see that it
really wasn't all that hard.
What you will learn
First, you will learn what CGI is, what a script is and how it works. Then,
you will learn about subroutines and how they can be re−used to save lots
of time and effort. You'll discover where to find free CGI scripts and how
to get them. You'll find out how to take a useful subroutine from one script
and use it in another script.

By applying what you've learned, you'll be able to create whole new
scripts "out of thin air" by putting together pieces you found here and
elsewhere.
You'll discover how CGI can make your Web site more interactive and
how to make it perform repetitive tasks automatically. Your Web site
should be able to work for you like a tireless employee. Your knowledge
of CGI scripts will make this possible.
You will learn how to install a script on your Web server. We will cover
using ftp to get the script into the right place, setting file permissions so
the script can be run and connecting it to your Web pages. You will see
how to tell whether the script is working properly and how to fix the most
common problems that keep it from behaving as intended.
You will learn how to collect the email addresses of your visitors, add
them to your mailing list and follow up with sales letters or other
information. By doing this, you'll be able find new prospects and turn them
into paying customers. You'll learn how to take payments and give
receipts − online and by email. You'll see how to do any math you need to
do and how to display properly formatted dollar amounts. Users of other
currencies may need to modify these routines somewhat, but the
principles will still apply.
You'll learn how to save data you collect in a database and extract usable
information from that data. You will learn how to deliver error pages,
thank−you pages and totally customized pages that are unique to each
visitor during their stay at your Web site.
What this book is NOT
This book is not an exhaustive reference for programming in Perl. If you
want to all about Perl, you'll need to get one or more of the excellent
books available on the subject. Some of these are listed in Appendix A.
For more guidance, visit the Perl home page:
http://www.perl.com
This book is also not a complete guide to installing scripts on every
possible type and configuration of Web server and/or hosting company.
That would require years of research and would fill many hundreds of
pages. Not only that, but it would need to be updated constantly.
3

There are many "quirks" associated with different servers which can make
installing a script more challenging. The basic principles are discussed
here. For most users, this will be enough to enable you to install your own
scripts.
If you are unable to get a script installed, it is usually best to talk to the
system administrator or the technical support personnel at your Web
hosting company. Many problems like this can be avoided if you carefully
follow the instructions and procedures given here.