[Athens-pm] cgi-html linking .... [EN Version]

[Philip Lees]

> I want that links when they are clicked to call some
> code from inside the perl script (in this case
> "login.pl" script). How can i do that, without the
> html's <A> tag!?

This is confusing - a clickable link means that there _must be_ an <A>
tag.

There are two ways of invoking a perl (or other CGI) script from a Web
page:

1. Use a form with one or more Submit buttons. Specify your script name
for the form's 'action' parameter and use fields (hidden fields if
necessary) to pass parameters to your script.

2. Use a direct link, e.g.

<a href="my_script.pl?argument1=string;argument2=123;argument3=no">Click
this</a>

If your arguments can contain spaces or strange characters you should
pass them through the URI::Escape module  to be sure the link will work
on all browsers.

It may be useful for you to look at the OpenECG Web site (which I
maintain :-] ):

http://www.openecg.net

The main part of the site is handled by just one Perl script, which is
passed arguments that tell it what to display for each link.

The code in your login.pl script looks fine. A couple of comments:

> my %levels = (0 => "\"the bastard\"",
>			  1 => "\"just another user\"",
>			  2 => "\"configure it!\"");

If you use single quotes you don't need to do the escaping, e.g.

my %levels = (0 => '"the bastard"',

But that's too hard to read, so use q:

my %levels = (0 => q("the bastard"),

Same here:

> $cgi->p('You\'re not logged in.',

$cgi->p( q(You're not logged in.),

It's good that you check the success of open:

> open (USERCOUNT, $file) or die ("Cannot open $file")

but if it ever fails, you won't know why. Get the error message from
perl:

open (USERCOUNT, $file) or die ("Cannot open $file: $!")

I hope this is of some help.

Philip
--
Philip Lees
Working Group on Cardiology
ICS-FORTH, Science and Technology Park of Crete
Vassilika Vouton, P.O. Box 1385, GR 711 10 Heraklion, Crete, GREECE

tel.: +30-2810-391680, fax: +30-2810-391601, e-mail: pjlees at ics.forth.gr

'The aim of high technology should be to simplify, not complicate' -
Hans Christian von Baeyer