Can't read text from file on OS 9

[Cubist at aol.com]

sez ambassador at fourthworld.com:
>Cubist at aol.com wrote:
>> sez ambassador at fourthworld.com:
>>>If you're running in OS 9 natively I'm stumped.  But if you're running
>>>Classic under OS X this is caused by paths being handled differently in
>>>OS 9 and Classic.
>>>You could account for this if it was possible to know if you're running
>>>9 natively or in Classic, but alas it is not.
>>    Correct me if I'm wrong, but isn't there a function that gives you the 
>> pathname of the topStack? If there is, it seems to me that you should be 
able to 
>> get that pathname, and from it, determine exactly how the current OS takes 
>> care of such things. Yes, this is an annoyance, but you should only need 
to do it 
>> once, during (pre)openStack... right?
>Yes, but the path returned by the Classic engine uses a form unique to
>running Classic under OS X (it excludes the volume name normally needed
>in OS 9, IIRC).
   Okay, it's a unique form of pathname. I get that. What I don't get is 
this: What prevents you from parsing the silly thing to determine whether or not 
it's a pathname for (a) honest-to-God MacOS 9, or (b) Classic under OS X? What 
*other* information, that's *not* in the topStack's pathname, would you need 
to make that determination? If the pathname of the topStack doesn't do it, I 
seem to recall something about a "specialFolders" function to ID stuff like the 
System Folder, the Preferences Folder, and so on -- maybe *that* would work?