Howdy,

Because of some latency issues in the display of dynamically created PNG 
images, I've been trying to separate the image-creation process from the 
image-display process. Essentially, I'm trying to run a cron job that 
writes a PNG image to file every 5 seconds. The php file pulls data from a 
MySQL db and creates a color-coded map of a cancer treatment building. The 
presence of normal levels of Neutrons would lead to the creation of a 
green flag, above-normal levels yields a yellow flag, and high levels 
yields a red flag. Another page will simply use a SRC tag to display the 
image, and will refresh every 5-6 seconds to get the latest 
readings/image.

The concept worked extremely well when the image was output to the 
browser, except for the fact that a latency caused the image in the 
browser to flicker when it refreshed.

So I've attempted the above, but without success, in that I can't get the 
cron job to actually make the image file. I know that the file is being 
processed because I can echo out a few words to the screen. And I know 
that the php file can create an image file because it does so when I add 
the file_name attribute to the imagecreate() function. 

I've checked permissions on folders, etc, and have tried both the CLI and 
SAPI versions of php, with and without available command line flags, but 
no luck. And it's not the db query portion of the process because I've 
commented out that portion of the code.

Pretty much stumped and very open to thoughts/comments. 

The Set Up: 
RH 9.0 
Apache 2.0.48
PHP 4.3.4
Mozilla 1.5
(MySQL 4.0.18)

Thanks,
 David

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