Display image via PERL

[1DMF]

I have toyed with this script for ages and couldn't work out how to get the image to display, then it came to me and thought I'd share as it took me ages searching to get the answer.

If you want to have a page with an image and the source is equal to the cgi script i.e.

<img src="url_to_cgi/image.cgi?ID=1" />

in the perl you would do the following...

#!/usr/bin/perl

######################
# Set Error Trapping #
######################

use CGI::Carp qw(fatalsToBrowser warningsToBrowser); 
use warnings;
use strict;

##################
# Use CGI Module #
##################
use CGI;

# Set new CGI
my $cgi = new CGI;

my $id = $cgi->param('ID');

# Set file
my $file = "path_to_file/$id.jpg";

# Set Headers
print "Content-type: image/jpeg\n\n";

# Open Image File
open(FILE, "<$file") || die "Error opening image file, seek support!";

[b]# Prepare STDOUT for binary data
binmode(STDOUT);[/b]

# Print File
print <FILE>;
close(FILE);
exit();

I have highlighted the important part, it is important to remember that you must prepare the STDOUT for binary data before printing the image content.

This example works for JPEG files, but you can easily change it for your required file type, and remember to change the MIME header content type .i.e.

# GIF
print "Content-type: image/gif\n\n";
# PNG
print "Content-type: image/png\n\n";

Hope it helps someone

Regards, 1DMF

"In complete darkness we are all the same, only our knowledge and wisdom separates us, don't let your eyes deceive you.

 

[PaulTEG]

Since you're using CGI anyways, might as well have it rolling the headers for you

print $q->header(-type=>'image/gif');

and sub image/gif for the appropriate MIME headers eg image/jpeg

Paul
------------------------------------
Spend an hour a week on CPAN, helps cure all known programming ailments ;-)

 

[1DMF]

yeah I guess, but I still prefer to type

print "Content-type: image/gif\n\n";

than

print $q->header(-type=>'image/gif');

just habbit and preference I supose and why is it $q and not $cgi ?

"In complete darkness we are all the same, only our knowledge and wisdom separates us, don't let your eyes deceive you.

 

[PaulTEG]

$q->... is straight from the docs, my apologies, should read $cgi->... in this context.

Headers can cause problems when hand rolled, typos etc, so where possible I like to use CGI for that.

Paul
------------------------------------
Spend an hour a week on CPAN, helps cure all known programming ailments ;-)