Images on fly using IIS

laszlo · Jun 2, 2004

A have the following html file:

<HTML><HEAD><TITLE=test</HEAD>
<BODY><CENTER>
<IMG SRC=http://localhost/cgi-bin/wpm/wimaker.pl/test.png>
</CENTER></BODY></HTML>

also the following perl file:

#!/usr/bin/perl

use CGI;
use CGI::Carp;
use Image::Magick;

my $image = Image::Magick->new(size=>'100x100');
$image->Read('xc:green');
$image->Write('test.png'); #testing reasons only

my $q = new CGI;
$| = 1;

print $q->header(-type=>"image/png",-expires=>"now",-status=>"200
Document follows");
$image->Write("png:-");

I get a broken image, and test.png file is not written. If I delete
$image->Write('test.png'); it will not change the result, I believe
the problem is wimaker.pl isn't called at all.

If I run wimaker.pl from command line test.png is created, it is
correct image and I got the following output:

Status: 200 Document follows
Expires: Wed, 02 Jun 2004 22:22:52 GMT
Date: Wed, 02 Jun 2004 22:22:52 GMT
Content-Type: image/png

‰PNG

followed with the binary data for the correct png file (the character
before PNG stands for 0x89)

I use WIN2000 IIS perl 5.8.0 ImageMagick 6.0.1

How can I make wimaker.pl to be called as image generator?

Ben Morrow · Jun 3, 2004

Quoth (e-mail address removed) (laszlo):

A have the following html file:

<HTML><HEAD><TITLE=test</HEAD>
<BODY><CENTER>
<IMG SRC=http://localhost/cgi-bin/wpm/wimaker.pl/test.png>

This needs quoting, as it contains slashes which are special to SGML.

</CENTER></BODY></HTML>

also the following perl file:

#!/usr/bin/perl

use CGI;
use CGI::Carp;
use Image::Magick;

my $image = Image::Magick->new(size=>'100x100');
$image->Read('xc:green');
$image->Write('test.png'); #testing reasons only

my $q = new CGI;
$| = 1;

print $q->header(-type=>"image/png",-expires=>"now",-status=>"200
Document follows");

binmode STDOUT;

$image->Write("png:-");

I get a broken image, and test.png file is not written.

Are you sure? I suspect is is, just not where you think. Insert

use Cwd;

at the top and add

-x_cwd => cwd

to your header call to see what the current directory is when the script is
run.

If I delete
$image->Write('test.png'); it will not change the result, I believe
the problem is wimaker.pl isn't called at all.

If I run wimaker.pl from command line test.png is created, it is
correct image and I got the following output:

Status: 200 Document follows
Expires: Wed, 02 Jun 2004 22:22:52 GMT
Date: Wed, 02 Jun 2004 22:22:52 GMT
Content-Type: image/png

<89>PNG

followed with the binary data for the correct png file (the character
before PNG stands for 0x89)

Are you sure? What happens if you direct output to a file and strip the
HTTP header off? I strongly suspect the lack of binmode was corrupting
the image.

Ben

gnari · Jun 3, 2004

[CGI problem]

print $q->header(-type=>"image/png",-expires=>"now",-status=>"200
Document follows");
$image->Write("png:-");

I get a broken image, and test.png file is not written. If I delete
$image->Write('test.png'); it will not change the result, I believe
the problem is wimaker.pl isn't called at all.

Ben has already pointed out the missing binmode here, so I will
go slightly (or even totally) OT:

doesn't everyone use a tool like GET or wget (or even telnet 80) in
this situation to examine server output ?
it amazes me to see 'I believe wimaker.pl isn't called' when
that is such a trivial thing to test.

gnari

John Bokma · Jun 3, 2004

gnari said:
"laszlo" <[email protected]> wrote in message

doesn't everyone use a tool like GET or wget (or even telnet 80) in
this situation to examine server output ?

I do, and tail -f access_log and a tail -f error_log

gnari · Jun 3, 2004

John Bokma said:
I do, and tail -f access_log and a tail -f error_log

along with massive
print STDERR "debug\n" if $debug;

gnari

laszlo · Jun 3, 2004

Ben Morrow said:
Quoth (e-mail address removed) (laszlo):

This needs quoting, as it contains slashes which are special to SGML.

The resolution is:

<IMG SRC=http://localhost/cgi-bin/wpm/wimaker.pl>

the program reference may not be followed by additional string. I dont
know why but in this way works neither the quoting nor binmode in the
called program is necessary

One more note for possibile future readers: the $| (autoflush) is
necessary, otherwise the header will follow the image)

thanks for the replay

Ben Morrow · Jun 4, 2004

Quoth (e-mail address removed) (laszlo):

The resolution is:

<IMG SRC=http://localhost/cgi-bin/wpm/wimaker.pl>

the program reference may not be followed by additional string.

This is then a question of server configuration. It is certainly
possible to configure the server to cause a request for
/cgi-bin/wpm/wimaker.pl/test.png to invoke wimaker.pl passing
'/test.png' as a parameter; your server may not be so configured.

I dont know why but in this way works neither the quoting nor binmode
in the called program is necessary

They are *both* necessary. The quoting of the URI has nothing to do with
Perl: it is a question of valid HTML. binmode is *always* necessary on
filehandles that will be fed binary data: if it happens not to have been
what bit you in this case, it will at some point.

Ben

Image::Magick->Write() doesn't want to write	2	Nov 16, 2009
CGI Perl on IIS	2	Apr 14, 2004
problem GD and my package Random->Random::new	13	Jan 21, 2007
Displaying images stored in mysql via webbrowser	6	Jan 16, 2004
Uploading images to imageshack.us with Python	3	Aug 22, 2005
At wits end! LWP and IIS(?)	6	May 5, 2004
confusing problem while using Mechanize to submit a form wit	0	Dec 8, 2008
Help with POST request using LWP?	2	Dec 6, 2003

Images on fly using IIS

laszlo

Ben Morrow

gnari

John Bokma

gnari

laszlo

Ben Morrow

Ask a Question

Similar Threads

Members online

Forum statistics

Latest Threads