Overview
CGI is something that helps add interactiy or cool features to your site.
CGI scripts have the extensions .cgi and .pl. There are a few different languages
that allow you to create CGI scripts. (CGI is not a programming language).
The main one is Perl. Perl CGI Scripts let you create search engine, mail
forms, guestbooks, message forums, create statistics of your site's viers,
and just about anything you want for your site. As you can see, Perl and CGI
are some pretty powerfull things for the net.
Requirements
Perl scripts require that your server is equiped with perl. If you are unsure
about this, contact your server administrator for help. You will have to find
out a few things about your server before uploading any perl scripts. You
should find out the system path of your site on the server, the location of
perl, the location of the sendmail, and the location of the date command.
Try looking at your server's support/faq page, or email your server administrator.
Also, if your server doesn't support Perl, don't hesitate to go to the Get
Hosted page and fill out the application to get hosted by me.
Editing Your Script
One of the best things in perl is the abbility to store information easily.
There are a few ways of doing this, but we will only get into two of them.
The two most commonly used methods are in scalars and arrays. Scalars are
used for storing single data. An example of a scalar is shown below:
$youremail = '[email protected]';
An array can be used in storing multiple data. An example of an array is shown
below:
@referers = ('warzone2000.com','208.161.8.40')
Moving around a perl script
There are only a few out of many things I'll explain in this section. One
of them is how to print new lines in the html field. To do this, you must
enter a \n in the perl script. Usually, it looks like this:
print "Hello\n";
wrather then:
print "hello";
The different between these two is that the first one will print out a new
line in the html code when somebody looks at the source. It makes it look
much neater.
Uploading Your Script
After editing all the variables in the script(s), save it, and exit. All Perl
Scripts have to be uploaded in ASCII mode, not binary. Log in to your FTP
account, and create a new folder on the server called cgi-bin, or whatever
the name of the folder with CGI capabilities is. Upload the script into that
folder. Now, here comes the hard part! Almost all Perl CGI script have to
be chmoded for them to work. Chmodding is also known as Changing the File
Permissions. This will allow/not allow your viewers to see or interact with
a designated file(s) on your server. (Chmodding can also be used to protect
a directory from being seen by chmodding it to a very low number). Most Perl
CGI Scripts have to be chmodded to 755. To find out how to chmod files using
your FTP, try reading the read me for it. For some FTP Programs, you can right
click on the file you want to chmod, and look for something like "Change File
Permissions" or "Chmod". Also, you can use telnet to chmod CGI scripts.
Using SSI in CGI
SSI is a very important part in CGI scripts. It allows you to call a cgi script
from a remote directory and print them on a designated page. Wrather then
having the url http://www.warzone2000.com/cgi-bin/board/board.cgi, I could
make the url something like http://www.warzone2000.com/board.shtml. An important
part in using SSI is renaming your .htm or .shtml file to .shtml or .shtm.
Some servers do not require this, but most do. The code for doing this is
shown below:
<!--exec cgi="/cgi-bin/cgiscript.cgi"-->
Replace that /cgi-bin/cgiscript.cgi with the location of the script. Say your
script was in /cgi-bin/downloads/antileech.cgi. This would be the code for
that:
<!--exec cgi="/cgi-bin/downloads/antileech.cgi"-->
To find out how to use SSI in other ways, go to the SSI Tutorial.
Resources
http://www.find-script.com/
http://cgi.resourceindex.com/
http://www.freeperlcode.com/