IsAstack ( )

[FlexibleLearning at aol.com]

Hi Trevor

Renaming the mainstack temporarily before trying "if there  is a stack" works 
fine, and I've not found a problem with substack collisions  when using it. 
Since, as you say, the call loads into memory, the engine  will figure out if 
it is incomplete or corrupted but it doesn't seem to go  further than that 
(like identifying shared substack names). There might,  however, be a collision if 
if you have a substack called mySubStk in an open  stack and then 
specifically asked
 
if "mySubStk" is among the lines of the substacks of stack tPath

Getting a bit esoteric at this point, however.

/H


>I haven't tried the above code but using "if there is  a stack" does  
>load a stack into memory so I would think the  collision would happen  
>with that call. What Jerry and I did for  Galaxy was write a function  
>to extract the stack name from disk  before trying to open it. That  
>was the only reliable method we  found to circumvent the problem.
>But not even that works if there is a  substack that will cause a name  
>collision.