Running a separate TCL process using hyper

[Bruce Edson <bruce@steptech.com>]

Sorry for sending this to both mail lists, but I figure until everyone has
moved over to the new one at SourceForge I will post to both.

We have created a TCL process that will augment the xref tables for Source
Navigator.  We want to do this so as to be able to cross-reference unique
macro method invocations in our code base.  As the process takes time we
would like to run it in a separate process much the way dbimp runs, although
we're using TCL to do this.  Now for the problem,  we can set up a pipe for
hyper to run the TCL script and that seems to work (we use 'open', and the
pipe seems to operate in both directions).  We would like to use a pipe so
that we can monitor progress and update a progress bar.  The problem is that
we can't find a way to know that the process has exited (to know when its
done).  The script has the TCL command 'exit 0' at the end.  We've tried
waiting for eof or for the pid to change, but it never does.  We've tried
sending back a unique string from the process so that the calling program
can then just 'close' the pipe.  The 'close' hangs.  I'm also left with a
hyper process still running in memory for any of these cases, so just not
waiting and continuing on, eventually gets me when I try to exit Source
Navigator.  Can someone give me a suggestion on how to get this hyper
process to end and a way to know that it has ended?

Thanks.

Bruce