Path: utzoo!attcan!uunet!lll-winken!lll-tis!helios.ee.lbl.gov!pasteur!ucbvax!GRIN1.BITNET!MCGUIRE
From: MCGUIRE@GRIN1.BITNET ("The Sysco Kid ", McGuire,Ed)
Newsgroups: comp.os.vms
Subject: Problem with F$PARSE
Message-ID: <8808030054.AA15820@ucbvax.berkeley.edu>
Date: 18 Jul 88 21:33:58 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
Lines: 44

Gentle Readers,

I am writing a command procedure under VMS V4.7, batch, SYSTEM account, which
periodically polls the running system, looking for evidence of software
failure.  For example, it looks through directories for files which should not
normally exist.  If it encounters a problem, it sends notification to one or
more locations.

The directory searches have been producing bizarre output.  I reduced the code
to a minimum and showed it and its output to the Customer Support Center, and
they are clueless. 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.

Any assistance will be greatly appreciated.

Ed

--------------------------------------------------------------------------------
$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"
[...total of 36 repetitions]
  FILESPEC = "SYS$SYSROOT:[SYSEXE]*.*;*"
  INSTANCE = "SYS$SYSROOT:[SYSEXE]AUTOGEN.PAR;23"
[37th repetition and all afterwards: F$PARSE returns null value]
  FILESPEC = ""
  INSTANCE = ""
  FILESPEC = ""
  INSTANCE = ""
[...this is repeated apparently without end]
--------------------------------------------------------------------------------