Re: Is there a way that I can tell if a web page on anotherweb site has changed.

One other thing.  If the page uses meta tags or is CGI,
then the most "sure" way would be to compare the page
contents of two requests.

This could be done fairly easily assuming the page isn't
larger than 32k (just the HTML, not any images, etc).

One way with my GETURI tool would be to use the API version
in a program that "runs forever".  It would make the
request and store the results in a work field (and you can
even tell GETURI to strip the headers out).

Then the next hour, it makes the same call and compares the
two results, and does whatever you want if there is a
change.  Then stores the latest results into the work field
again.

It may tie up a little memory.  :)  But at least you
wouldnt have to mess with the IFS.

Brad
www.bvstools.com

On Tue, 14 Jun 2005 13:33:21 -0500 (CDT)
 web400@xxxxxxxxxxxxxxxx wrote:
> Hello,
> 
> >I am using socket methods to make http requests to
> certain web sites
> >every hour and I want to alert a user if the web page on
> another site
> >changes.  Can anyone tell me an easy way to do this.
> 
> Send the "IF-MODIFIED-SINCE" header on the HTTP request.
> The server will then only re-send the page if it has been
> modified since the date/time you send.
> 
> Example:
> 
> GET /index.html HTTP/1.1
> Host: www.example.com:80
> If-Modified-Since: Tue, 14 Jun 2005 12:46:05 GMT
> 
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Bradley V. Stone
BVS.Tools
www.bvstools.com