Why Aren't You Using CGI?

Why Aren't You Using CGI?

by Michael Southon



The very name CGI used to send chills up my spine. For

years I put it in the 'too-hard-basket'. But like most

things in life, CGI is not as scary as it seems. If

you have a cgi directory on your website and you know

how to FTP files, chances are you can have a CGI

script up and running in less than 20 minutes.



CGI (Common Gateway Interface) is not a programming

language but a standard that allows visitors to

interact with your website. CGI scripts can be written

in a number of different languages but most are

written in Perl (Practical Extraction and Reporting

Language).



This article gives you details of five free CGI scripts

that will do the following:



1. Mail out your Newsletter from your server

2. Track the number of times your free E-Book is

downloaded

3. Rotate banners on your website

4. Create your own auto responders

5. Allow visitors to recommend your website to friends



At the end of this article are details of where to

download these 5 free scripts. But first, here are

some basic guidelines on how to configure and install

CGI scripts:





1. CGI programs usually come in a zip file. Unzip the

file and open the README file. This document will give

you instructions for configuring the program file.





2. Open the program file using a text editor such as

NOTEPAD (the program file will usually have the file

extension .cgi but may have other extensions such as

.pl).



In most CGI programs you will have to configure the

following 4 items:



(a) the path to perl



This is where the perl program resides on your server.

The path will usually be:



#!/usr/bin/perl



but could be:



#!/usr/local/bin/perl



If you're unsure what your 'path to perl' is, check

your web host's online 'manual' or FAQs. If you can't

find it there, simply ask your web host.





(b) the path to sendmail



Most CGI programs notify you when your visitors have

completed a particular action, and for that, the

program needs to know where the 'sendmail' program

resides on your server. The path to your UNIX sendmail

program will usually be: /usr/sbin/sendmail



But it could also be something like this:

/usr/lib/sendmail



Again, check the documentation on your web host's

website, or simply ask your web host.





(c) the absolute path to your CGI directory



The absolute path tells the CGI program exactly where

to find the file (or files) that it needs to open.

Unfortunately, the absolute path to your CGI directory

is not something you will be able to guess or deduce -

it is completely arbitrary and depends entirely on how

the system administrator at your web host has

partitioned your host's hard drive.



The easiest way to find out your absolute path is to

ask your web host. Another way is by using telnet -

just type in pwd (print working directory) and that

should give you your absolute path.





(d) Your email address



This is the address that the CGI program will use to

notify you when an action has been completed.





3. Uploading



Upload the program files to your cgi-bin (or a

directory off your cgi-bin) using ASCII mode. Never

use BINARY mode, as this will play havoc with the

line-breaks in the script.





4. Set the File Permissions using CHMOD



CHMOD (changing mode) is the term for setting security

permissions on files. The README file will usually

tell you the permissions that you need to set for each

file. The script file will need to be set to 755. This

allows the file's owner to read, write, and execute

the file; anyone else can only read and execute it.



You can set the permissions using telnet, but the

easiest way is to use the built-in option in your FTP

program.





5. Calling the Script



Now that you've configured the script, uploaded it and

set the permissions, it's time to try it out! You do

this by 'calling the script' using a URL in an HTML

document. This is what the URL for calling your script

will normally look like:



http://www.yourdomain.com/cgi-bin/script.cgi



Again, the README file should have specific

instructions on how to call the script. In addition,

most CGI programs are accompanied by a web page

that contains the form your visitors would use to

call the script.





And now here are the details of the 5 free CGI

scripts I mentioned earlier:



-----------------------

Subscribe Me Lite

-----------------------



Subscribe Me Lite is a program that allows

prospects/customers to automatically subscribe and/or

unsubscribe themselves from your mailing list. It has

a built-in mass mailing form for sending out your

newsletter or updates.



More Information:

http://www.cgiscriptcenter.com/subscribe/index2.html



-----------------------

Rob's File Tracker

-----------------------



Rob's File Tracker is a perl script that counts file

downloads or click-thrus to any file. Very useful if

you want to know how many people are downloading your

free E-Book.



More Information:

http://www.robplanet.com/cgi/tracker/



-----------------------

AdRotate Pro

-----------------------



AdRotate Pro is an ad rotation program that's easy to

setup and easy to use. Features include unlimited

rotations, expiry by date, views or clicks, default

ads for when all ads are expired, and customer

reports.



More Information: http://www.vanbrunt.com/adrotate/



-----------------------

MasterRecommend

-----------------------



This script allows visitors to recommend your website

to a friend by sending an email, without leaving your

website. The program will also send you a copy of your

visitor's message (nice to know what your visitors

think about your website).



More Information:

http://www.willmaster.com/master/recommend/MasterRecommendmanual.html



-----------------------

Master Auto-Responder

-----------------------



This is a standard auto-responder program. The

script allows you to set the "From:" and "Subject:"

lines for your auto-response.You can also choose to

receive a copy of each email that the auto-responder

receives.



More Information:

http://mastercgi.com/howtoinfo/howautoresponderswork.shtml





If you need more help installing your CGI scripts, here

are two excellent free tutorials:



http://spider-food.net/install-a-cgi-script.html

http://www.stefan-pettersson.nu/scripts/tutorials/installcgi.html