Printing errors to browser

[Kelicula]

Does anyone know of a way that I can have the errors on a cgi script be funneled to the http output?

I have use warnings, and the

or die "can't open it $!\n";

But still to this day I have never seen what is in $!. Or recieved a warning.

All I ever get is Internal server error, or it works.

Another thing that is very weird, I was working on this set transparant color, with the GD module, and it worked fine. Here is the script:

#!user/bin/perl
 
use strict;
use warnings;
use GD;
 
my $image = GD::Image->newFromJpeg("../img/logoTest.jpg");
my $black = $image->colorResolve(0,0,0);
$image->transparent($black);
$image->interlaced('true');
my ($width,$height) = $image->getBounds();
my $count = 0;
for (my $x = 0; $x < $width; $x++) {
     for (my $y = 0; $y < $height; $y++) {
         my $color = $image->getPixel($x,$y);
         my ($r,$g,$b) = $image->rgb($color);
         if ($r < 30 && $g < 30 && $b < 30) {
             $image->setPixel($x,$y,$black);
             $count++;
         }
     }
 }
print "$count\n";
open(FILE, ">../img/background2.png") || die "Cannot open background2.jpg: $!\n";
print FILE $image->png;
 

However I noticed that I had grabbed the wrong jpg to set transparency for, so I changed it

my $image = GD::Image->newFromJpeg("../img/otherOne.jpg");

And now it doesn't work. Internal error.

I have looked through it for hours now, and can't see what I messed up. I litarally just changed four or five characters.

I'd love to get the errors to the screen
Thanks!!

PS -
I tried running it on my local machine, but it says GD is not found. Can't open GD/Image found in C:/perl/bin/lib (or whatever the path was I'm not looking at the error now)

[numberwhun]

Does anyone know of a way that I can have the errors on a cgi script be funneled to the http output?

I have use warnings, and the

or die "can't open it $!\n";

But still to this day I have never seen what is in $!. Or recieved a warning.

All I ever get is Internal server error, or it works.

Another thing that is very weird, I was working on this set transparant color, with the GD module, and it worked fine. Here is the script:

#!user/bin/perl
 
use strict;
use warnings;
use GD;
 
my $image = GD::Image->newFromJpeg("../img/logoTest.jpg");
my $black = $image->colorResolve(0,0,0);
$image->transparent($black);
$image->interlaced('true');
my ($width,$height) = $image->getBounds();
my $count = 0;
for (my $x = 0; $x < $width; $x++) {
     for (my $y = 0; $y < $height; $y++) {
         my $color = $image->getPixel($x,$y);
         my ($r,$g,$b) = $image->rgb($color);
         if ($r < 30 && $g < 30 && $b < 30) {
             $image->setPixel($x,$y,$black);
             $count++;
         }
     }
 }
print "$count\n";
open(FILE, ">../img/background2.png") || die "Cannot open background2.jpg: $!\n";
print FILE $image->png;
 

However I noticed that I had grabbed the wrong jpg to set transparency for, so I changed it

my $image = GD::Image->newFromJpeg("../img/otherOne.jpg");

And now it doesn't work. Internal error.

I have looked through it for hours now, and can't see what I messed up. I litarally just changed four or five characters.

I'd love to get the errors to the screen
Thanks!!

PS -
I tried running it on my local machine, but it says GD is not found. Can't open GD/Image found in C:/perl/bin/lib (or whatever the path was I'm not looking at the error now)

One of our resident experts (KevinADC), has written a tutorial on CGI under the Articles section of this site. In there, under the Modules section, you will find the following:

use CGI::Carp qw/fatalsToBrowser/;
 

along with an explanation. I recommend the tutorial as it is an excellent beginning. (as far as I have seen as I am still reading it)

Regards,

Jeff

[KevinADC]

To expand on that, you can aso print warnings. see the "MAKING WARNINGS APPEAR AS HTML COMMENTS" in the CGI::Carp documentation.

[KevinADC]

There is a new module that looks interesting:

CGI::Carp::DebugScreen