Riffing on DrByte's suggestion, if you happen to be using a recent Linux kernel (2.6.13 and higher) you can use a handy tool such as incron. Before you read this--it's a no-go unless you've got at least a virtual dedicated server. If your server is Linux, you can check your kernel version
by typing
from a shell. If it's 2.6.13 you will be able to install and set up incron.
Then you can find your mysql data directory. If you use Webmin, you can go to System->Users and Groups. One of the users in the table is a daemon named mysql. Her home directory is the mysql data directory. Let's say it's something like "/path/to/mysql"
Next, look inside that directory. You will see a directory for each of your databases, including one for zencart.
When a row is added or modified in a mysql table "tablename" the file that changes will be "tablename.MYI".
From the command line, as root (or any user who can see the table you're interested in) do
and add the line
Code:
/path/to/mysql/dbname/tablename.MYI IN_MODIFY php /path/to/yourphpscript.php
I should point out that some serious thought about the control logic is required here. For instance, you might consider adding an extra "status" column to the table, defaulting to "0". The php script yourphpscript.php could read the lines that have a "0" in the extra column and act on those columns that have 0's and when it's done with them, change them to 1's if the action is successful, or a 2 if it's unsuccessful.
The script yourphpscript.php can do just about anything. For that matter, you can put any command you like after "IN_MODIFY". (I'm currently working on something similar for a client who needs his Zen Cart stock synced with his ebay stock!).