Calling a script via img tag

nca

I have noticed that some tracking scripts use this "hidden" tag to place in html pages in order to active a script and usually it passes a variable through to the script also...

<img src="http://www.site.com/script.php?id=47" border=0 width=1 height=1>

My question is, what is the script.php supposed to have in it in order to make the tag not show a broken image tag in the browser when you remove the width and height attributes? Or is it always going to have to be shown as a broken image?

Merve

This, in actuality, may be a script to create an image using the PHP Image Functions. What they do is that a dynamic image is created using the functions, then a header is sent to change the mimetype of the script so that it outputs as an image. I'm not an expert on the subject, but I believe that the script used to create the image may also be used to do other things, such as tracking.

nca

Ok so there is a php function to output an image? So you can call a php script via a img html tag and it will show an image?

Anyone know of any online tutorials that may describe this? I have been googling for a while now 🙂

_theworks

GD Image functions php.net [man]imagecreate[/man] even better.... download php_manual_en.chm from here... http://www.php.net/get/php_manual_en.chm/from/a/mirror

mark_79_smith

It doesn't even need to create an image on the fly.

You can just have your script to do it's stuff then at the bottom of the script do a Header("Location: /images/blank.gif"); exit();

For example

//Start code
include('../connect.php');
$sql = mysql_query($query);
Header("Location: /images/blank.gif"); exit();

//End Code

This code will then show the image in your Header tag after it has processed what it needs to do

nca

Great! I think I'll be using mark_79_smith's idea.

Thanks!!