From: watson@maple.terabase.com
Sent: Tuesday, September 21, 1999 10:24 PM
To: Info-VAX@Mvb.Saic.Com
Subject: Re: Process Permanent Files

In article <37E7FA37.78B9BB41@videotron.ca>, JF Mezei 
  <jfmezei.spamnot@videotron.ca> writes:
>
>Does anyone know what the last two bytes really mean/come from in the logical
>name that is created when you $OPEN from DCL ?
>
They are an IFI, and they do point to an IFAB, but in a sneaky way.  RMS 
actually keeps a separate list of IFABs (and I assume other structures) for 
each access mode (well, not Kernel, because RMS routines themselves only 
run in Executive).  A PPF IFI is a reference to an Executive mode IFAB.  
You can see this if you try sticking it into an empty FAB structure, attach 
a NAM block, and call SYS$DISPLAY:

  - If you leave the PPF bit set and call in user mode, you get the PPF
	logical name in the NAM;
  - If you clear the PPF bit and call in user mode, you get an error;
  - If you clear the PPF bit and use SYS$CMEXEC to call SYS$DISPLAY, you
	get the real name of the file.

I have a small routine that uses this to get the name of a network job's
SYS$OUTPUT file (including correct version number) into a symbol, so it
can rename it to an appropriate directory without worrying about all the
other instances of the job trying to do the same thing.

--
George Watson				watson_g@eisner.decus.org
