Article 129234 of comp.os.vms:
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From: carl@SOL1.GPS.CALTECH.EDU (Carl J Lydick)
Newsgroups: comp.os.vms
Subject: Re: /since qualifier with different commands
Date: 14 Sep 1995 01:04:09 GMT
Organization: HST Wide Field/Planetary Camera
Lines: 173
Distribution: world
Message-ID: <437v29$atc@gap.cco.caltech.edu>
References: <436a16$1o4@rzsun02.rrz.uni-hamburg.de> <437ela$khp@gap.cco.caltech.edu>,<13SEP199517351015@eql.caltech.edu>
Reply-To: carl@SOL1.GPS.CALTECH.EDU
NNTP-Posting-Host: sol1.gps.caltech.edu

In article <13SEP199517351015@eql.caltech.edu>, rankin@eql.caltech.edu (Pat Rankin) writes:
=In article <437ela$khp@gap.cco.caltech.edu>,\
= shoppa@altair.krl.caltech.edu (Tim Shoppa) writes...
=[...]
=> So I would make a wild-assed guess that DELETE checks things in this order:
=> (1).  Could you delete the file if you wanted to?
=> (2).  Does it meet the date selection criteria specified?
=> and it complains about (1) even if (2) isn't satisfied.  I imagine
=> this could be important to you if the warning exit status from delete was
=> enough to screw up one of your command files.
=
=     If you want a simpler theory:  it has to access the file in order
=to obtain the date values.  It's not possible to make any date comparison
=without first getting ahold of the relevant date info from the file header.
=DIRECTORY knows how to circumvent locked file access and does so, which
=makes sense since the consequences of it happening to get inconsistent
=data are fairly benign.

The following might be instructive (I knew SET WATCH had to be useful for
something :-).  At any rate, DELETE attempts an ACCESS of files matching the
specification; DIRECTORY doesn't.  My guess (I don't have access to the
listings at the moment) is that DIRECTORY is calling the QIO/ACP interface
directly, while DELETE is working through RMS and using SYS$OPEN to get the
date information about the files in question.

$ SET PROC/PRIV=CMEXEC
$ SET WATCH FILE/CLASS=ALL
$ SET PROC/PRIV=NOCMEXEC
$ DIRECTORY/SINCE=TOMORROW TEST.DAT
%XQP-I-FUNCTION, FIB contents:
	 00000000 0002010B 00000000 00000000 00000000 00000000 00000000 00000000
	 00000000 00000000 00000000 00030000 00000000 00000000 00000000 00000000
%XQP-I-FUNCTION, FIB contents:
	 00000000 0002010B 00000000 00000000 00000000 00000000 00000000 00000000
	 00000000 00000000 00000000 00030000 00000000 00000001 00000000 00000000
%XQP-I-FUNCTION, Read attributes: Record attributes CARL.DIR;1 (267,2,0)
%XQP-I-FUNCTION, Read attributes: User file characteristics CARL.DIR;1 (267,2,0)
%XQP-I-FUNCTION, Read attributes: File header CARL.DIR;1 (267,2,0)
%XQP-I-FUNCTION, Access CARL.DIR;1 (267,2,0) Status: 00000001
%XQP-I-FUNCTION, FIB contents:
	 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
	 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
%XQP-I-FUNCTION, FIB contents:
	 00000000 0002010B 00000000 00000000 00000000 00000000 00000000 00000000
	 00000000 00000000 00000000 00000000 00000000 00000001 00000000 00000000
%XQP-I-FUNCTION, Deaccess (267,2,0) Reads: 1, Writes: 0, Status: 00000001
%XQP-I-FUNCTION, FIB contents:
	 00000000 0498311C 00000000 00000000 00000000 00000000 00000000 00000000
	 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
%XQP-I-FUNCTION, FIB contents:
	 00000000 0498311C 00000000 00000000 00000000 00000000 00000000 00000000
	 00000000 00000000 00000000 00000000 00000000 00000001 00000000 00000000
%XQP-I-FUNCTION, Read attributes: Record attributes TEST.DAT;5 (12572,1176,0)
%XQP-I-FUNCTION, Read attributes: Creation date TEST.DAT;5 (12572,1176,0)
%XQP-I-FUNCTION, Read attributes: Revision date TEST.DAT;5 (12572,1176,0)
%XQP-I-FUNCTION, Read attributes: Expiration date TEST.DAT;5 (12572,1176,0)
%XQP-I-FUNCTION, Read attributes: Backup date TEST.DAT;5 (12572,1176,0)
%XQP-I-FUNCTION, Read attributes: Statistics block TEST.DAT;5 (12572,1176,0)
%XQP-I-FUNCTION, Read attributes: Owner UIC TEST.DAT;5 (12572,1176,0)
%XQP-I-FUNCTION, Read attributes: File protection TEST.DAT;5 (12572,1176,0)
%XQP-I-FUNCTION, Read attributes: User file characteristics TEST.DAT;5 (12572,1176,0)
%XQP-I-FUNCTION, Read attributes: ASCII dates TEST.DAT;5 (12572,1176,0)
%XQP-I-FUNCTION, Read attributes: Journal flags TEST.DAT;5 (12572,1176,0)
%XQP-I-FUNCTION, Read attributes: Find ACE by type TEST.DAT;5 (12572,1176,0)
%XQP-I-FUNCTION, Read attributes: Find ACE by type TEST.DAT;5 (12572,1176,0)
%XQP-I-FUNCTION, Read attributes: Find ACE by type TEST.DAT;5 (12572,1176,0)
%XQP-I-FUNCTION, Read attributes: ACL length TEST.DAT;5 (12572,1176,0)
%XQP-I-FUNCTION, Read attributes: Find ACE by type TEST.DAT;5 (12572,1176,0)
%XQP-I-FUNCTION, Read attributes: RU active TEST.DAT;5 (12572,1176,0)
%XQP-I-FUNCTION, Read attributes: Find ACE by type TEST.DAT;5 (12572,1176,0)
%XQP-I-FUNCTION, Lookup TEST.DAT;5 (12572,1176,0) Status: 00000001
%DIRECT-W-NOFILES, no files found
$ DELETE/CONFIRM/SINCE=TOMORROW TEST.DAT;
%XQP-I-FUNCTION, FIB contents:
	 00000000 00000000 010B0000 00000002 00000000 00000100 00000000 00000000
	 00000000 00000000 00000000 00030000 00000000 00000000 00000000 00000000
%XQP-I-FUNCTION, FIB contents:
	 00000000 00000000 010B0000 00000002 00000000 00000100 00000000 00000000
	 00000000 00000000 00000000 00030000 00000000 00000001 00000000 00000000
%XQP-I-FUNCTION, Read only directory access (267,2,0)
%XQP-I-FUNCTION, Directory scan for: TEST.DAT;0, Status: 00000001
%XQP-I-FUNCTION, Lookup  (12572,1176,0) Status: 00000001
%XQP-I-FUNCTION, FIB contents:
	 00000000 00000000 010B0000 00000002 00000000 00000100 00000000 00000000
	 00000000 00000000 00000000 00030000 00000000 00000000 00000000 00000000
%XQP-I-FUNCTION, FIB contents:
	 00000000 00000000 010B0000 00000002 00000000 00000100 00000000 00000000
	 00000000 00000000 00000000 00030000 00000000 00000001 00000000 00000000
%XQP-I-FUNCTION, Read only directory access (267,2,0)
%XQP-I-FUNCTION, Directory scan for: TEST.DAT;0, Status: 00000001
%XQP-I-FUNCTION, Lookup  (12572,1176,0) Status: 00000001
%XQP-I-FUNCTION, FIB contents:
	 00200001 0498311C 00000000 00000000 00000000 00000000 00000000 00000000
	 00000000 00000000 00000000 01030000 00000000 00000000 00000000 00000000
%XQP-I-FUNCTION, FIB contents:
	 00200001 0498311C 00000000 00000000 00000000 00000000 00000000 00000000
	 00000000 00000000 00000000 01030000 00000000 00000001 00000000 00000000
%XQP-I-FUNCTION, Access TEST.DAT;5 (12572,1176,0) Status: 00000800
%XQP-I-FUNCTION, FIB contents:
	 00000001 0498311C 00000000 00000000 00000000 00000000 00000000 00000000
	 00000000 00000000 00000000 01030000 00000000 00000000 00000000 00000000
%XQP-I-FUNCTION, FIB contents:
	 00000001 0498311C 00000000 00000000 00000000 00000000 00000000 00000000
	 00000000 00000000 00000000 01030000 00000000 00000001 00000000 00000000
%XQP-I-FUNCTION, Access TEST.DAT;5 (12572,1176,0) Status: 00000800
%DELETE-W-FILNOTACC, file not accessible DISK$USERDISK:[CARL]TEST.DAT;5
-RMS-E-FLK, file currently locked by another user

And when running the following program:

#include rms
#define ckstat(x) if (((stat = x) & 7) != 1) SYS$EXIT(stat)
main()
{	struct FAB my_fab;
	unsigned long stat, SYS$OPEN(), SYS$CLOSE();
	
	my_fab = cc$rms_fab;
	my_fab.fab$l_fna = "test.dat";
	my_fab.fab$b_fns = strlen(my_fab.fab$l_fna);
	my_fab.fab$b_fac = 0;
	my_fab.fab$v_bio = 1;
	ckstat(SYS$OPEN(&my_fab));
	ckstat(SYS$CLOSE(&my_fab));
	printf("%s has %d blocks allocated.\n", my_fab.fab$l_fna,
		my_fab.fab$l_alq);

}

we see:

$ r test
%XQP-I-FUNCTION, FIB contents:
	 FF010841 00000000 010B0000 00000002 00000000 00000000 00000000 00000000
	 00000000 00000000 00000000 00010000 00000000 00000000 00000000 00000001
%XQP-I-FUNCTION, FIB contents:
	 FF010841 00000000 010B0000 00000002 00000000 00000000 00000000 00000000
	 00000000 00000000 00000000 00010000 00000000 00000001 00000000 00000001
%XQP-I-FUNCTION, Read only directory access (267,2,0)
%XQP-I-FUNCTION, Directory scan for: TEST.EXE;0, Status: 00000001
%XQP-I-FUNCTION, Read attributes: Access mode TEST.EXE;51 (17616,132,0)
%XQP-I-FUNCTION, Read attributes: Access mode TEST.EXE;51 (17616,132,0)
%XQP-I-FUNCTION, Read attributes: Journal flags TEST.EXE;51 (17616,132,0)
%XQP-I-FUNCTION, Read attributes: RU active TEST.EXE;51 (17616,132,0)
%XQP-I-FUNCTION, Read attributes: Statistics block TEST.EXE;51 (17616,132,0)
%XQP-I-FUNCTION, Read attributes: Find ACE by type TEST.EXE;51 (17616,132,0)
%XQP-I-FUNCTION, Read attributes: Record attributes TEST.EXE;51 (17616,132,0)
%XQP-I-FUNCTION, Read attributes: User file characteristics TEST.EXE;51 (17616,132,0)
%XQP-I-FUNCTION, Access TEST.EXE;51 (17616,132,0) Status: 00000001
%XQP-I-FUNCTION, FIB contents:
	 00000001 00000000 010B0000 00000002 00000000 00000000 00000000 00000000
	 00000000 00000000 00000000 01030000 00000000 00000000 00000000 00000000
%XQP-I-FUNCTION, FIB contents:
	 00000001 00000000 010B0000 00000002 00000000 00000000 00000000 00000000
	 00000000 00000000 00000000 01030000 00000000 00000001 00000000 00000000
%XQP-I-FUNCTION, Read only directory access (267,2,0)
%XQP-I-FUNCTION, Directory scan for: TEST.DAT;0, Status: 00000001
%XQP-I-FUNCTION, Access TEST.DAT;6 (14720,20,0) Status: 00000800
%RMS-E-FLK, file currently locked by another user
%XQP-I-FUNCTION, FIB contents:
	 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
	 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
%XQP-I-FUNCTION, FIB contents:
	 00000000 008444D0 00000000 00000000 00000000 00000000 00000000 00000000
	 00000000 00000000 00000000 00000000 00000000 00000001 00000000 00000000
%XQP-I-FUNCTION, Deaccess (17616,132,0) Reads: 4, Writes: 0, Status: 00000001
--------------------------------------------------------------------------------
Carl J Lydick | INTERnet: CARL@SOL1.GPS.CALTECH.EDU | NSI/HEPnet: SOL1::CARL

Disclaimer:  Hey, I understand VAXen and VMS.  That's what I get paid for.  My
understanding of astronomy is purely at the amateur level (or below).  So
unless what I'm saying is directly related to VAX/VMS, don't hold me or my
organization responsible for it.  If it IS related to VAX/VMS, you can try to
hold me responsible for it, but my organization had nothing to do with it.