[<<]Message[>>]    [<<]Author[>>]    [<<]Subject[>>]    [<<]Thread[>>]

Number   :  7157
Date     :  2004-02-04
Author   :  Kan Yabumoto
Subject  :  Re: Command File Dir Exclusions
Size(KB) :  3


Michael wrote:
> On stardate Tue, 03 Feb 2004 14:30:16 -0000, while visiting
> Deep Space 9, the changeling Founder wjaiv spake thusly:
>
>> What is the proper syntax for excluding directory, *wherever* they
>> may exist... be it at the root of a volume, in a subdirectory, or
>> even buried deep in a subdirectory? I've tried a few variations:
>> /X:\*\BADDIR\
>> /X:BADDIR\
>> /X:\BADDIR\
>>
>> Which way is correct? Thanks!
>
>
> /X:"\*\*\baddir\"

Well, the \*\*\ sequence will be folded into the shortest
equivalent form \*\.

Therefore, the following lines are equivalent.

/X:\*\*\*\*\BADDIR\
/X:\*\*\*\BADDIR\
/X:\*\*\BADDIR\
/X:\*\BADDIR\

(the shortest one in this case is preferred).

Don't be confused this from the special endings

/X:dir_name\
/X:dir_name\*
/X:dir_name\?\*
/X:dir_name\*\*

All these are explained in the XXTB #05 article but
let me show some of the essence.

XXCOPY views a directory as made up of two types
of components.

files
subdirectories

We wanted XXCOPY to exclude either of these
types of components rather than just a directory
with everything in it. With the extremely tight
budget in the allowed characters, we came up with
the following notation to denote the two types.

files in a directory /X:dir_name\*
subdirectories in a directory /X:dir_name\?\*

If you combine the two types of components in
a directory, it become a "whole" (everything in it).

So, /X:dir_name\* and
/X:dir_name\?\*

combined, then you get,

/X:dir_name\*\* (i.e., everything in it)

which is also the same thing as

/X:dir_name\

Here, the point I wanted to make is the following
two are distinct:

/X:dir_name\*
/X:dir_name\*\*

But, the following three are equivalent

/X:*\dir_name\
/X:*\*\dir_name\
/X:*\*\*\dir_name\

But, these are different from

/X:?\*\dir_name\

-------------------------------------------------
Note the ?\ sequence everywhere except at the
ending that is shown earlier has the regular
meaning of one character-pathname followed by
zero-or-more levels of directory of anything
which is followed by the pattern, \dir_name\
which is different from the four special way
ending of a directory pattern.
------------------------------------------------

-----------

Let me further clarify a few cases of the
syntax rules that may be confusing


/X:\*\BADIR\
/X:BADIR\

The difference between the two is that
the first one is a directory that matches
\BADIR\ at any level including the root level
(\*\ may collapse to nothing), whereas the
second one does not have wildcard to the
left and therefore it does not have the
specification for the "any-level-of" meaning.

Similarly, /X:\BADIR\ simply denotes the
pattern (in this case without a wildcard)
at the root level.


Finally, what is the difference betwee the
following two?

/X:\*\BADDIR\
/X:*\BADDIR\

Even though the mechanism to arrive the
result is different, the second one is
equivalent to the first one.

1st: any \BADDIR\ at any level under root
2nd: any \ABDDIR\ at any level under the
source base directory.

Actually, the scope of the 2nd pattern is
smaller than the first one (parent directory
of the base directory and any level above
are not included). But, the XXCOPY operations
always affects objects which are at the base
directory level or lower levels (to the right),
the 2nd (narrower) set of directories covers
all the affected directories and therefore,
the two always become equivalent in practice.

----------

TIP:

To know which exclusion patterns are taken
by XXCOPY, you should verify the result of
the "pre-processing" step inside XXCOPY by
adding the /oX switch.

E.g., (compare the two)

xxcopy \src\ /X:\*\BADDIR\ /oX/DEBUGX
xxcopy \src\ /X:\*\*\BADDIR\ /oX/DEBUGX

(The /DEBUGX switch will show you the
list of exclusion items and terminate the
command after the command line processing
before the actual file copy actions take
place).

Kan Yabumoto



This message if part of XXCOPY's message Archive.
The archive contains all the messages posted at Yahoo!Groups: XXCOPY.