Posted by Marek Kilimajer on 11/26/08 11:16

Rahul S. Johari wrote:
> On 5/18/05 6:23 PM, "Marek Kilimajer" <lists@kilimajer.net> wrote:
>
>
>>BTW, you might not be concerned about it much, but you have a race
>>condition in your script.
>
>
> Ave,
>
> What do you mean by "race condition" ?

If more then one user is accesing the page, you might overwrite the
first one's verify.png image. Simple and sufficient solution is to
append a random string to the filename:

$image_filename= 'verify_' . md5(rand()) . '.png';
ImagePNG($im, $image_filename);
?>
<img src="<?php echo $image_filename; ?>" width="200" height="40">
<?php

Just remember to add some way to remove old images.

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