CGI Scripts

• Scripts must be made executable by typing "chmod 755 filename" after logging in.
• Any script must end in .cgi to ensure execution.
• Scripts that dont respond with Content Type tag as first LIne, must be named nph-Scriptname.cgi . The nph- stands for non-parsed-headers.
• Perl 5 is located at /usr/bin/perl make sure the first line has this right or else!
• Perl 4 scripts usually will need to have any @ or $ escaped with \ character to be perl 5 compatible. ie print "webmaster\@yourdomain.com"
• The directory cgi-bin is reserved for our shared cgi directory. You can use a directory other than cgi-bin or icons to store your scripts. Actually the cgi-bin is mapped to our /usr/local/www/cgi-bin/ so you can use our cgi scripts with your domain.com and not have to make duplicate copies of the files.
• index.cgi is valid, as a directories home page for a cgi script. Like wise you could replace index.htm with index.shtml to use PARSE(Servier Side includes).
• <!-- Server Side includes --> only work in files with .shtml extension. The execute bit and read public bits must be on to use .shtml.
• <!--exec cgi="mycgi.cgi" --> is a cool way to output the result of a simple cgi script into the middle of somefile.shtml .
• If you can't figure out why it doesn't work , run it from the command line, or rename it to nph-Scriptname. You'll see more error messages.
• CGI is programming, don't be mistaken into thinking it is as easy as HTML. You might want to try a consultant.
• If you are going to use perl , buy a Perl book, please.
• If you can't figure it out, ask us, we will help you by email on a time permits basis.

My First CGI SCRIPT - myfirst.cgi

#!/bin/sh
echo Content-type: text/plain
echo
echo 10 print "HELLO"
echo 20 goto 10
echo Hello there I see you saw my page at $HTTP_REFERER
echo You are using $HTTP_USER_AGENT as a browser.
echo $HTTP_USER_AGENT >> agentfile.txt
echo \&lta href=\"http://mydomain.com\"\> Home \</a\>

Yawn - Notice the \ escapes, the blank echo after the content-type line. Also If you want to use agentfile.txt line, i had to upload a blank file called agentfile.txt, and then use the file manager to set PUBLIC WRITE on that file. Or the script will not work! (telnet: touch agentfile.txt;chmod o+w agentfile.txt)

Helpful links

Matt's Script Archive
- A great collection of miny perl scripts that are free to use. This site is highly recommended if you are just beginning to learn perl and CGI.

Basic Procedure for Executing a Perl Script from a WebPage
- A basic, and helpful, tutorial on how to set-up a CGI script- using a 'counter' as an example

Galaxy's CGI- Common Gateway Interface
- Lots of information on CGI scripting, and the longest URL on the Web, including pointers for more information on image mapping, etc.

O'Reilly & Associates
- Don't normally recommend books, but in the case of Perl, Unix, Linux, Scripting, etc. your might need to read-up with the best.

The Common Gateway Interface
- An introduction (with examples) to CGI scripting. One of the best sites.

The processing of CGI arguments under TCL
- More information on CGI.

Imagemap Help Page
- Imagemaping made simple in an easy to follow guide.

HTGREP
- if you need a searchable index, this is supposed to do the trick. I haven't messed with it yet, though.

NASA's 'Information on Search Tools'
- a interesting page with many ideas on solving local searching problems.

PERL
- A great language to learn in the generation of dynamic documents (on-the-fly page creation) such as forms.