Web interface with a cgi script

DirtyDan · 10-04-2004, 08:35 PM

Im trying to set this up, and right now to do what it needs to its great. All it does is runs a cgi script that opens a C programs with a given input, coded into the CGI. I want to create and html file that can use a for with check boxes to send a combination of data to a similar cgi file. Let me show you the code, it will help.
The first cgi:

Code:

#!/bin/sh
# Parallel port CGI script
# This would be controller.cgi, obviously my form will not do anything to supply this
# Send HTTP headers
echo Content-type: text/html;charset=ISO-8859
echo
# Do the controlling
/usr/sbin/lptest 0        /*<----This is what i want to be able to change, with any value from 0 to 255*/
# Output web page data
echo "<html><head></head><body>"
echo "Parallel port controlled<br>"
echo "<a href=\"/link1.html\">Go back to controlling page</a>"
echo "</body></html>"
#

And what i would do (kinda, just missing the actual working parts :rollseyes

Code:

<html>
<body>

<form name="input" action="controller.cgi"
method="post">
Pin 1
<input type="checkbox" name="Pin 1">
<br>
Pin 2
<input type="checkbox" name="Pin 2">
<br>
Pin 3
<input type="checkbox" name="Pin 3">
<br>
Pin 4
<input type="checkbox" name="Pin 4">
<br>
Pin 5
<input type="checkbox" name="Pin 5">
<br>
Pin 6
<input type="checkbox" name="Pin 6">
<br>
Pin 7
<input type="checkbox" name="Pin 7">
<br>
Pin 8
<input type="checkbox" name="Pin 8">
<br>
<input type="submit" value="Submit">
</form>

</body>
</html>

My hope was to make one checkbox worth 1, one worth 2, one worth 4, etc up to 8, and add these together then send that number to the cgi so that it can run my C file (which im using from HeRe )

How do I edit the two files? Sorry for the excessive amount of code, its really simple probably to you guys I just wasnt sure how to explain my question. Thanks a ton!

Its really is a mess, but thanks a ton secesh. I'll try to make it more readable. What you made worked great!

secesh · 10-04-2004, 10:43 PM

well... this is a cluster-f***
first- comment what script belongs to what filename
second- this is not CGI -- you're throwing around all kinds of files -- an sh script, a reference to an asp page...

third -- i have no real idea of what you're trying to accomplish, but here's how you throw form data around with perl. Also, i'm a little rusty, and not going to test this, so it is what it is.

Code:

#!/usr/bin/perl
###########
## Moray ##
###########
## filename: parallel.cgi
#
print "Content-Type: text/html\n\n";
use CGI;
my $q = new CGI;
## TODO: Error catch!
system("/usr/sbin/lptest ".$q->param("my_val"));
# Output web page data
print "<html><head></head><body>";
print "Parallel port controlled<br>";
print "<a href=\"/link1.html\">Go back to controlling page</a>";
print "</body></html>";

and the html file includes this form with action to parallel.cgi

Code:

<form action="parallel.cgi" method="post">
    <input type="text" name="my_val" value="0" />
    <input type="submit" />
</form>

DirtyDan · 10-05-2004, 12:14 AM

Ok, im getting the hang of this sorta. But for some reason, my cgi now ALWAYS gives me 255?

Code:

/*link1org.html*/
<html>
<body>

<form name="input" action="/cgi-bin/lpton2.cgi"
method="get">
User Name
<input type="text" name="user" size=30 maxlength=20>
<br>
Password
<input type="password" name="pass" size=30 maxlength=20>
<br>
Pin 1
<input type="checkbox" name="Pin_1">
<br>
Pin 2
<input type="checkbox" name="Pin_2">
<br>
Pin 3
<input type="checkbox" name="Pin_3">
<br>
Pin 4
<input type="checkbox" name="Pin_4">
<br>
Pin 5
<input type="checkbox" name="Pin_5">
<br>
Pin 6
<input type="checkbox" name="Pin_6">
<br>
Pin 7
<input type="checkbox" name="Pin_7">
<br>
Pin 8
<input type="checkbox" name="Pin_8">
<br>
<input type="submit" value="Submit">
</form>

</body>
</html>

And...

Code:

#!/usr/bin/perl
###########
## filename: lpton2.cgi
#
print "Content-Type: text/html\n\n";
use CGI;
my $q = new CGI;
## TODO: Error catch!
$tot=0;
for($coun=0;$coun<=7;$coun++)
{
    if ($q->param("Pin_".($coun+1))=="on")
        {
            $tot+=2**$coun;
        };
};
system("/usr/sbin/lptest ".$tot);
# Output web page data
print $tot;
print "<html><head></head><body>";
print "Parallel port controlled<br>";
print "<a href=\"/link1org.html\">Go back to controlling page</a>";
print "</body></html>";

Yeah, the user and pass do nothing yet, but thats ok. It's stupid anyways. But why is my conditional statement " if ($q->param("Pin_".($coun+1))=="on") " always coming back true??

chrism01 · 10-05-2004, 06:28 AM

In Perl, numeric 'equal' tst is '==', string 'equal' test is 'eq' ! It's prob cvt both stings to 'true' => 1...

DirtyDan · 10-05-2004, 07:33 AM

Wow, thanks, switched it to eq and its working great! Is eq equivalent to =?
Nevermind, I see, I need it for a string conditional. This is great, i have username and pass stuff working too now.. Thanks again!

secesh · 10-05-2004, 07:58 AM

no.

perl handles variables a little differently. it does not make a difference between string variables and numerical variables, they are all 'scalars' to perl.

therefore, you must watch what operators you use while manipulating scalars:
eq is NOT the same as ==.

look at what this does as a quick example:

Code:

#!/usr/bin/perl
###########
## Moray ##
###########
my($val1, $val2, $val3, $val4);
$val1 = 1;
$val2 = 1;

$val3 = "apples";
$val4 = "oranges";

print($val1+$val2);print "\n";
print($val1.$val2);print "\n";

if($val1==$val2){
        print "$val1 == $val2\n";
}
if($val3 == $val4){
        print "$val3 == $val4\n";
}
if($val3 eq $val4){
        # Not eq!
}else{
        print "NOT($val3 eq $val4)\n";
}

you get this output:

Code:

2
11
1 == 1
apples == oranges
NOT(apples eq oranges)