From freezineweb.com
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:
Mail out your Newsletter from your server
Track the number of times your free E-Book is downloaded
Rotate banners on your website
Create your own auto responders
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:
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Subscribe Me Lite
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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
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Perl File Download
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Is a download program that keeps track of who downloads files from your site. You simply put a link to the program from one of your pages and it sends your visitor to the download program with a list of available programs for download.
More Information:
http://darian1271.hypermart.net/
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MasterRecommend
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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
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Master Auto-Responder
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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
(c) 2001 by Michael Southon