At 16:49 19/10/99 , Jeff Rush wrote:
Hmmm, I'm staring at web sites that -do- update their graphic content, such as weather display sites and the MRTG (network graph stats) program, and I don't see anything like a variable URL.
How do they manage it? The only new item I see is the use of:
<META HTTP-EQUIV="Refresh" CONTENT=300> <META HTTP-EQUIV="Expires" CONTENT="...a date">
While this would cause the HTML to refreshed periodically, how are they getting the browser to re-fetch the *images*? I've captured the HTML source for several iterations and the <IMG SRC="blah"...> part never changes, so I would expect the same graphic would keep appearing on each cycle.
possibly the src= of the <img> points to a cgi program that returns "Expires: (something soon)" headers so it wont get cached. in perl pseudocode (sorry i'm not that accustomed to python yet) you'd write something like this: # this from thimble smith, tim@desert.net # read image data $img = <wherever you get the image data from, gif assumed> # print expires with date=now print "Expires: ", scalar(localtime), "\r\n"; # or whatever content, then insert gif data print "Content-type: image/gif\r\n\n$img" hth? peter. -- _________________________________________________ peter sabaini, mailto: sabaini@niil.at -------------------------------------------------