Stacks and substacks of a filename

[Matt Denton]

Heya-all.  I've been having stacks of fun...

I've been wading through the docs again, trying to find out what the 
mainStack and subStacks of a file is.  For example, what is the 
mainstack and substacks of "/mydisk/revdocs/thisStack.rev"?  Can you 
find this out without opening the file and loading into memory?

I've checked: openstacks; mainstacks; mainstack; substacks; the 
stackFiles; owner; effective filename; and stacks property.   It is 
pretty easy to find the filename of a stack, and substacks of a 
mainstack, ie the reverse of what I wan to do.  Or the mainstack of a 
substack.  But I'm stumped trying to find the stacks in a file, plus any 
substacks.

I must be overlooking something pretty simple, oui?  I can do a kludge 
by comparing the list before and after, but this seems pretty 
convoluted, plus you have to load the file.  Plus you have to cycle 
through to find which  of the new list is the mainstack.  There is an 
easier way, right?  I'm just up too late, right?

Any help would be appreciated.

Cheers,

M@