Path: utzoo!utgpu!attcan!uunet!convex!killer!ames!pasteur!ucbvax!GOLD.BACS.INDIANA.EDU!ijah400%ivax.DECnet
From: ijah400%ivax.DECnet@GOLD.BACS.INDIANA.EDU ("IVAX::IJAH400")
Newsgroups: comp.os.vms
Subject: RE: Problem with F$PARSE
Message-ID: <8807291705.AA01444@ucbvax.berkeley.edu>
Date: 22 Jul 88 17:25:00 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
Lines: 44

"The Sysco Kid (McGuire,Ed)" <MCGUIRE%GRIN1.BITNET@CUNYVM.CUNY.EDU> writes:
< Gentle Readers,
<...
<                   I'm attaching it here.  In brief, an F$PARSE call appears to
< stop returning a value after it has been called with identical arguments a
< number of times.
<...
< ------------------------------------------------------------------------------
< $LOOP:
< $       CALL SUBR
< $       GOTO LOOP
< $
< $SUBR:
< $       SUBROUTINE
< $       FILESPEC = F$PARSE ("SYS$SYSTEM", "*.*;*")
< $       INSTANCE = F$SEARCH (FILESPEC)
< $       SHOW SYMBOL FILESPEC
< $       SHOW SYMBOL INSTANCE
< $       ENDSUBROUTINE
< ------------------------------------------------------------------------------
<   FILESPEC = "SYS$SYSROOT:[SYSEXE]*.*;*"
<   INSTANCE = "SYS$SYSROOT:[SYSEXE]AUTOGEN.PAR;23"
<   FILESPEC = "SYS$SYSROOT:[SYSEXE]*.*;*"
<   INSTANCE = "SYS$SYSROOT:[SYSEXE]AUTOGEN.PAR;23"
<...

CALL sets up a whole new procedure context, like @filespec does.  In other
words, don't use CALL anywhere where @filespec wouldn't work either.
Try using GOSUB/RETURN instead, e.g.:

$       FILESPEC = F$PARSE ("SYS$SYSTEM", "*.*;*")
$LOOP:
$       GOSUB SUBR
$	IF INSTANCE .EQS. "" THEN EXIT
$       GOTO LOOP
$
$SUBR:
$       INSTANCE = F$SEARCH (FILESPEC)
$       SHOW SYMBOL FILESPEC
$       SHOW SYMBOL INSTANCE
$	RETURN

     - Jim Harvey
     ijah400@indyvax (bitnet) or ijah400%ivax.decnet@gold.bacs.indiana.edu