PRINTing images in CGI script (HTML tags reqd.)

resetreset · 02-09-2009, 08:38 AM

Hello,
I have an image (a photo) in a variable (obtained from a MySQL database), eg. $ary[4]. I wish to display it in my Perl CGI script. My question is, th normal image tag ie. <IMG> takes a SRC parameter of a *file*, whereas I just want to PRINT the image in the variable. What tags must I surround it with?

Thanks.

theNbomr · 02-09-2009, 02:19 PM

Your SRC parameter can be of the form "http://servename.whatever/cgi-bin/yourCgi.pl?theNameOfTheImageFile". Your perl script would then just print the file to it standard output.

Code:

#! /bin/perl -w
#
use strict;
	print "Content-Type: image/png\n\n";
	open( IMAGEFILE, $ARGV[0] ) || die "Cannot open '$ARGV[0]' : $!\n";
	while( my $imageData = <IMAGEFILE> ){
		print $imageData;
	}
	close IMAGEFILE;
	exit;

You will probably want to do something more graceful for error exit, and also modify the mime-type according to the type of file you are dumping.

--- rod.

resetreset · 02-22-2009, 09:36 AM

I can't do that as the script outputs a lot of things besides the photo, the photo is just one of them.
Any more suggestions?

Thanks.

theNbomr · 02-22-2009, 10:38 AM

HTML does not provide for what you are attempting to do. Inline images are fetched by the browser as separate HTTP requests, and not as image data embedded in the HTML document. An HTML document is always formed from non-binary 'human-readable' text, and image data would not fit this criteria.
If your photo image is a static image, and not generated by code on-the-fly, and if it is stored somewhere in a server's document root, simply embedding the image URL in the HTML <IMG> tag generated by your CGI script should suffice. Otherwise, the method I gave can be used, but rather than simply opening the static image file, your second CGI can generate the image as necessary for your application, and print it with the appropriate Content-Type header.
--- rod.