>Is there a way to programatically know if another process has a table open in a DBC?

You can test it like this:

lcError = on('error')
on error *

use mytable in 0

on error &lcError
return used('mytable')

If the table is open somewhere else in your system, you'll get an error 3. If the table is open exclusive any where, youl'l get an error 1705. But all you get returned is a .T. or .F.