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Number   :  5061
Date     :  2003-07-22
Author   :  Kan Yabumoto
Subject  :  Re: /RX switch problem....
Size(KB) :  9


Garry wrote:

>--- In xxcopy@yahoogroups.com, "thoughtsandideas"  wrote:
>
> > I didn't know you could press "?" to see switches that
> > would suppress the prompt; I'll try that.
> >
> > Also, you said:
> >
> >> For example, /clone uses /PD0 which suppresses
> >> prompting before each directory copy/remove
> >
> > If that's true, then it's broken, because I *do* get
> > prompted... anytime it's about to delete a dst dir that's
> > absent in the src. And that's without using /RX. /RX just
> > adds more prompts -- it prompts me to delete dirs that it
> > shouldn't even be deleting, because they *do* exist in the
> > src.
>
>Interestingly, Andreas also reported a similar problem with
>prompting when using /clone. I can't replicate your problem
>but maybe there is a bug. I assume the source is a network
>drive. What is the destination? If you don't sort it out, try
>the following command then cut and paste the contents of
>xxcopy.log back here. Also advise which directories you are
>being prompted on - is there anything unusual about the names?
>
>xxcopy z:\data\ k:\backup\data\ /CLONE/FF/NX0/PZ0/ON:xxcopy.log

Sorry for my long explanation but I need to give you
detailed account for what went on to the design of the
features in question. (This message looks like a
technical bulletin.)

Let me concentrate on the original combination that is
alleged to have a bug. /CLONE /RX (I will come back to
the "funny combination" of the two).

I'm not sure if XXCOPY is really trying to delete anything
which should not be. My guess is that the way /PD prompt
is worded is giving the impression that XXCOPY is trying
to delete the whole directory. Let me concede that the
wording, due to the limited number of characters to use in
the context may give such an impression.

Say, you run the following command:

xxcopy \dir1\ \dir2\ /clone /rx

Now, /RX being a destructive command, it gives you two
levels of prompt. First, because it is a file-delete
operation, it gives you a file-by-file prompt

\dir2\myfile1.txt Delete (Y/N/A) ?

This one is the easiest one to understand. To suppress
this type of confirmation prompt, you need to put /RXY.
(actually, /RX /Y is equivalent to /RXY, but we discourage
the use of /Y in this context because /Y was originally
designed (by Microsoft's XCOPY) to give a prompt for
an overwrite of existing file in the destination.

In order to provide fine control for a large scale file
deletion (which is what XXCOPY is really aiming),
we feel it is not sufficient for all-or-nothing, or
one-by-one only control. Therefore, we created the /PD
switch (stands for Prompt-on-each-directory). XXCOPY
implicitly adds the /PD switch on all destructive operations.

So, unless you explicitly add /PD0, any of the removal
operations (/RS, /RD, /RC, /RX) will come with the
silent /PD switch.

The idea for /PD is that it will give you the complex
(flexible) prompt everytime XXCOPY is about to process
a directory.

E.g.,

xxcopy \src\ \dst\ /s /pd // for non-destructive action

Before XXCOPY starts to process a new subdirectory, say,
\src\dir1\

xxcopy will prompt Dir (Y/N/A/R/S) ?

for which you may reply

Y // yes on this directory
N // no (skip) this directory
A // yes to this and all of the rest
(this is essentially to dismiss the prompt for good)
R // yes to this and the rest of the sister directories
(but not aunt directories nor cousin directories)
S // yes to this and all of its subdirectories

Notice that with the /PD function, you will have more than
the common /Y/N/A prompt (which is only slightly better than
an all-or-nothing choice).

OK, let me use graphic illustration. I like to use female
for a directory and male for file.

+--mother
| |
| +------older sister (already processed)
| |
| +------me (current dir)
| | |
| | +------- daughter1
| | | |
| | | +------- grandson1 (file)
| | |
| | +--------daughter2
| | |
| | +--------son1 (file)
| |
| +----- sister2
| | |
| | +--------nephew1
| |
| +----- sister3
|
+--aunt1
|
+--aunt2

Y will enable processing me and my offsprings
N will skip me (therefor, all of my offsprings)
A will discard the prompt for good
R will enable me (and my offsprings plus sisters)
S will enable me and daughters and sons and grandchildren

Y and N is self explanatory. Note, Y does not
automatically enable my daughters or sons. The
remaining three choices are in the order of
the scope of their effects. If we want to skip
daughter1 (and grandson1), but to process daugher2
(and its offsprings), such selection should not
affect our ability to control sister2 and sister3
independently. Also, whatever we choose to control
near me (and my sisters) should not force us to
give up control on aunt1 and aunt2. That is why
the "R" (rest of my immediate family) is handy.
(but, it is hard to explain and certainly hard
for typical users to understand this)
This is more complete coverage on this topic than
any other material that I have documented so far.

Here, I used the word "enable" because /PD is not
always for file deletion but can be for file copy
(usually, the /PD switch is implicitly introduced
to "protect" user files from accidental deletion).

So, if you run any of /RS, /RC, /RD, /RX (and /Z,
you will get /PD (which requires /PD0 to disable it).

As to the wording of the prompt for /PD,
I said earlier for copy operations it is in the form of

Dir (Y/N/A/R/S) ?

For file-removal operations, the /PD prompt will say

RmDir (Y/N/A/R/S) ?

We could have used the uniform, "Dir (Y/N/A/R/S) ?",
but we chose this wording to emphasize the deletion
aspect of it. But, it does not say files will be
deleted even if you respond by "Y" at this point.
This prompt is simply a gatekeeper of the entrance
of a directory. To prove this (you can experiment
this without jeopardizing your files).

xxcopy \src\ \dst\ /rx /s /pd

Since you did not say /rxy nor /y, the command will
give you not only the directory-by-directory prompt,
it will give you file-by-file prompt.

So, you may respond to the first prompt

RmDir (Y/N/A/R/S) ? by typing "Y" to it.

The prompt will be overwritten and you will see

Directory Processed at the place where you

saw the RmDir ... prompt. But, immediately at
the next file, it will prompt you by

\src\dir1\myfile1.txt Delete (Y/N/A) ?

This (file-by-file) prompt is controlled independently
from the group of /PD prompt --- as I said earlier,
there are two levels of prompting.

I know this is confusing. If you don't like the
idea, you may permanently forget about it by always
adding /PD0 and you will have one less thing to
worry. But, we have responsibility to make sure that
XXCOPY users (especially new users) won't lose a lot
of files before becoming familiar with XXCOPY.
(If the tools does not perform any deletion, we would
not be as paranoia about this).

I know, this aspect of the prompt control is quite
messy. It is probably not the best way dealing
with the problem. But, you have to remember that
XXCOPY is designed to handle thousands of files.
Therefore, an All-or-nothing prompt control or
one-by-one prompt is not sufficient.

I as the designer of this prompt feature get annoyed
like everyone else. Whenever I use a manual invocation
of XXCOPY for deletion, I still prefer to let the
default /PD feature enabled rather than disabling it
by /PD0. Yes, I will be annoyed and after several
keystrokes of 'Y', I will use 'R' or even 'A'. I
don't use the 'S' very often but have used many times.

File deletion is always mentally exhausting operation.
Since XXCOPY does not let you "undelete", you need
the two level protection (on-directory and on-file).

It is messy. But, we have to get used to it.
Of course, these are features for manual control.
Once you create a batch file, you need to suppress
the prompts.

---------

Now, as to the combination of /CLONE and /RX.

/CLONE is essentially /BI/ZY (copy operation with
Zapping the extra files) where as /RX is Zapping
the extra without file-copy. The files selected
by /ZY and /RX for deletion are identical.

By paring /CLONE and /RX, you are giving up the
/BI (copying aspect) of /CLONE but still taking
advantage of the other combination /S. But,
it would be simpler (and preferred) to say /RX/S.

I now regret that we created the /RX function.
When it was invented, we wanted to provide the
functionality of /ZY without copying files.
We were aware of the better alternative (/RS/BB)
to the /RX operation. But, /RX being related to
the popular /ZY function made sense at that time.
But, the prompt control for the /ZY operation as
well as the /RX is getting too messy indeed.

My recommendation for you us to reverse the
order of the directory arguments.

Instead of XXCOPY \SRC\ \DST\ /RX/S
better use XXCOPY \DST\ \SRC\ /RS/BB/S

The reason why the second one is superior is
because you may use a lot more file-selection
mechanisms such as /DA/DB/SZ:/H/R/AT/AX which
won't have effect in the first case. This is
almost a hidden pitfall. Whether you like it
or not, these switches have no effect on an
/RX operations. That is because /RX is a
special case of /Z and most experienced XXCOPY
users will agree that /Z must not be affected
by the read-only attribute or anything.

That is why if you really want to have a
fine control of what files are to be deleted,
you should bring the target files onto the
center stage (the first argument).

Let me come back to my original message:

I don't think the alleged bug with /CLONE /RX
combination really exists. It is just the poor
wording in the prompt which misleads many people.

Thanks for reading this long message.

Kan Yabumoto



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