Hello!

I have some problem with Compare-Object. My task is to get difference
between two directory snapshots made at different times. First
snapshot is taken like this:

> ls -recurse d:\dir | export-clixml dir-20100129.xml

Then, later, I get second snapshot and load first:

> $b = (ls -recurse d:\dir)
> $a = (import-clixml dir-20100129.xml)

Next, I'm trying to compare with Compare-Object, like that:

> diff $a $b

What I get is in some places files that were added to $b since $a, but
in some -- files that were in both snapshots, and some files, that
were added to $b, are not given in Compare-Object output. Puzzling,
but $b.count - $a.count is EXACTLY the same as (diff $a $b).count. Why
is that?

Ok, Compare-Object has -property param. I try to use that:

> diff -property fullname $a $b

And I get the whole mess of differences: it shows me ALL the files.
For example, say $a contains:

A\1.txt
A\2.txt
A\3.txt

And $b contains:

X\2.mp3
X\3.mp3
X\4.mp3
A\1.txt
A\2.txt
A\3.txt

diff output is something like that:

X\2.mp3 =>
A\1.txt <=
X\3.mp3 =>
A\2.txt <=
X\4.mp3 =>
A\3.txt <=
A\1.txt =>
A\2.txt =>
A\3.txt =>



Weird. I think I don't understand something crucial about Compare-
Object usage, and manuals are scarce... Please, help me to get the
DIFFERENCE between two directory snapshots. Thanks in advance

IMO it is cause by the Export/Import-CliXml, because this works as
expected:

$a = "A\1.txt
A\2.txt
A\3.txt" -split "`n"

$b = "X\2.mp3
X\3.mp3
X\4.mp3
A\1.txt
A\2.txt
A\3.txt" -split "`n"

Compare-Object $a $b
(i use "`n" cause "`r`n" doesn't work in posh console)

I'll check the problem later. Meantime you coul export-clixml the $b
collection, import it back and compare the $a and $b.
Both are cli-imported so then it could work

On Jan 29, 8:07*pm, uj <andrey.balag...@newsgroup> wrote:

> Hello!
>
> I have some problem with Compare-Object. My task is to get difference
> between two directory snapshots made at different times. First
> snapshot is taken like this:
>

> > ls -recurse d:\dir | export-clixml dir-20100129.xml

>
> Then, later, I get second snapshot and load first:
>

> > $b = (ls -recurse d:\dir)
> > $a = (import-clixml dir-20100129.xml)

>
> Next, I'm trying to compare with Compare-Object, like that:
>

> > diff $a $b

>
> What I get is in some places files that were added to $b since $a, but
> in some -- files that were in both snapshots, and some files, that
> were added to $b, are not given in Compare-Object output. Puzzling,
> but $b.count - $a.count is EXACTLY the same as (diff $a $b).count. Why
> is that?
>
> Ok, Compare-Object has -property param. I try to use that:
>

> > diff -property fullname $a $b

>
> And I get the whole mess of differences: it shows me ALL the files.
> For example, say $a contains:
>
> A\1.txt
> A\2.txt
> A\3.txt
>
> And $b contains:
>
> X\2.mp3
> X\3.mp3
> X\4.mp3
> A\1.txt
> A\2.txt
> A\3.txt
>
> diff output is something like that:
>
> X\2.mp3 =>
> A\1.txt <=
> X\3.mp3 =>
> A\2.txt <=
> X\4.mp3 =>
> A\3.txt <=
> A\1.txt =>
> A\2.txt =>
> A\3.txt =>
>
> Weird. I think I don't understand something crucial about Compare-
> Object usage, and manuals are scarce... Please, help me to get the
> DIFFERENCE between two directory snapshots. Thanks in advance

When the $a is exported and imported as clixml, the types change.
System.IO.FileInfo objects
change to Deserialized.System.IO.FileInfo. I don't know the internals,
but I would bet this is the problem.

If you will compare like this:
$a = ls -recurse d:\dir | select -exp FullName | export-clixml
dir-20100129.xml
$a = import-clixml dir-20100129.xml
....
$b = ls -recurse d:\dir | select -exp FullName

there should be no problem. String is serialized and deserialized as
string.

On Jan 29, 8:07*pm, uj <andrey.balag...@newsgroup> wrote:

> Hello!
>
> I have some problem with Compare-Object. My task is to get difference
> between two directory snapshots made at different times. First
> snapshot is taken like this:
>

> > ls -recurse d:\dir | export-clixml dir-20100129.xml

>
> Then, later, I get second snapshot and load first:
>

> > $b = (ls -recurse d:\dir)
> > $a = (import-clixml dir-20100129.xml)

>
> Next, I'm trying to compare with Compare-Object, like that:
>

> > diff $a $b

>
> What I get is in some places files that were added to $b since $a, but
> in some -- files that were in both snapshots, and some files, that
> were added to $b, are not given in Compare-Object output. Puzzling,
> but $b.count - $a.count is EXACTLY the same as (diff $a $b).count. Why
> is that?
>
> Ok, Compare-Object has -property param. I try to use that:
>

> > diff -property fullname $a $b

>
> And I get the whole mess of differences: it shows me ALL the files.
> For example, say $a contains:
>
> A\1.txt
> A\2.txt
> A\3.txt
>
> And $b contains:
>
> X\2.mp3
> X\3.mp3
> X\4.mp3
> A\1.txt
> A\2.txt
> A\3.txt
>
> diff output is something like that:
>
> X\2.mp3 =>
> A\1.txt <=
> X\3.mp3 =>
> A\2.txt <=
> X\4.mp3 =>
> A\3.txt <=
> A\1.txt =>
> A\2.txt =>
> A\3.txt =>
>
> Weird. I think I don't understand something crucial about Compare-
> Object usage, and manuals are scarce... Please, help me to get the
> DIFFERENCE between two directory snapshots. Thanks in advance

On Jan 29, 9:23*pm, stej <cerna.ze...@newsgroup> wrote:

> If you will compare like this:
> $a = ls -recurse d:\dir | select -exp FullName | export-clixml
> dir-20100129.xml

Actually, both snapshots are imported with Import-Clixml. But I tried
to dump them just as strings with:

> $a | % { $_.fullname } | out-file a.txt
> $b | % { $_.fullname } | out-file b.txt

And, once again, Compare-Object gives me a whole lot of "differences":

> diff (get-content a.txt) (get-content b.txt)

I've event tried it with UNIX diff, and it actually gives reasonable
output.

--
Best Regards, Andrey Balaguta

For me this works as expected:

gci D:\temp\test\ -rec | select -exp fullname | Out-File d:\temp
\outfile1.txt
#...change something
gci D:\temp\test\ -rec | select -exp fullname | Out-File d:\temp
\outfile2.txt
Compare-Object (gc D:\temp\outfile1.txt) (gc D:\temp\outfile2.txt)

Could je publish somewhere the files to examine them?

On Jan 29, 8:39*pm, uj <andrey.balag...@newsgroup> wrote:

> On Jan 29, 9:23*pm, stej <cerna.ze...@newsgroup> wrote:
>

> > If you will compare like this:
> > $a = ls -recurse d:\dir | select -exp FullName | export-clixml
> > dir-20100129.xml

>
> Actually, both snapshots are imported with Import-Clixml. But I tried
> to dump them just as strings with:
>

> > $a | % { $_.fullname } | out-file a.txt
> > $b | % { $_.fullname } | out-file b.txt

>
> And, once again, Compare-Object gives me a whole lot of "differences":
>

> > *diff (get-content a.txt) (get-content b.txt)

>
> I've event tried it with UNIX diff, and it actually gives reasonable
> output.
>
> --
> Best Regards, Andrey Balaguta

On Jan 29, 9:55*pm, stej <cerna.ze...@newsgroup> wrote:

> Could je publish somewhere the files to examine them?

Here's archive with excerpts of both snapshot (top 100-something
lines, a.txt and b.txt), output of compare-object, and output of UNIX
diff (unified). All files are UTF-8:

http://91.204.198.27/compare-object-problem.zip

--
Best Regards, Andrey Balaguta

On Jan 30, 10:35*am, uj <andrey.balag...@newsgroup> wrote:

>
> Here's archive [...]
>
> http://91.204.198.27/compare-object-problem.zip
>

Just a follow-up. If that link is unavailable, please use the
following link: http://dl.dropbox.com/u/2873752/comp...ct-problem.zip

--
Best Regards, Andrey Balaguta

I downloaded your files and tried to compare it. Here is the result:

[3]: Compare-Object (gc D:\temp\posh-compare-object-problem\a.txt) (gc
D:\temp\posh-compare-object-problem\b.txt)

InputObject
SideIndicator
-----------
-------------
D:\music
\5'nizza
=>
D:\music
\Playlists
=>
D:\music
\RÄ‚ÅŸn
=>
D:\music
\SunSay
=>
D:\music\�šŃ€�µ�Ľ�°Ń‚�ľŃ
€�¸�ą =>
D:\music\5'nizza\2002 -
Unplugged =>
D:\music\5'nizza\2002 - Unplugged\01 - �ˇ�ľ�»�´�°Ń
‚.mp3 =>
D:\music\5'nizza\2002 - Unplugged\02 - Ä�źŃŹŃ‚Ä�Ë�Ä�¸Ńâ€*Ä�
°.mp3 =>
D:\music\5'nizza\2002 - Unplugged\03 - �Ż�Ľ�°�ą�ş�
°.mp3 =>
D:\music\5'nizza\2002 - Unplugged\04 - �ˇŃŽŃ€���
°ŃŹ.mp3 =>
D:\music\5'nizza\2002 - Unplugged\05 - �ˇ�
°��.mp3 =>
D:\music\5'nizza\2002 - Unplugged\06 - �Ż Ń� Ń‚�ľ�
±�ľ�ą.mp3 =>
D:\music\5'nizza\2002 - Unplugged\07 - �˘Ń‹ �ş�¸�´�
°�».mp3 =>
D:\music\5'nizza\2002 - Unplugged\08 - �Ż ���µ Ń
‚�ľ�ą.mp3 =>
D:\music\5'nizza\2002 - Unplugged\09 - �ˇŃ‚Ń€�µ�»�
°.mp3 =>
D:\music\5'nizza\2002 - Unplugged\10 - �’�ľ�´�
°.mp3 =>
D:\music\5'nizza\2002 - Unplugged\11 - �Ż Ń‚�µ�±ŃŹ
�˛Ń‹.mp3 =>
D:\music\5'nizza\2002 - Unplugged\12 - �’�µŃ����
°.mp3 =>
D:\music\5'nizza\2002 - Unplugged\13 -
Bigbadboom.mp3 =>
D:\music\5'nizza\2002 - Unplugged\14 - �ť�µ�˛�
°.mp3 =>
D:\music\5'nizza\2002 - Unplugged\15 - �ˇ�˛�ľ�±�ľ�´�
°.mp3 =>
D:\music\5'nizza\2002 - Unplugged\16 - ��ш�µ�´Ńˆ�¸�Ľ Ń��»�¸Ńˆ�ş�ľ�Ľ Ń
€�°���ľ.mp3 =>
D:\music\5'nizza\2002 - Unplugged\17 - ���¶�
°�Ľ�¸��.mp3 =>
D:\music\5'nizza\2002 - Unplugged
\folder.jpg =>
D:\music\Johnny
Cash
<=
[4]:

It looks ok. I have no idea what is going on there on your computer.
What versions ov PowerShell do you use? V2?

On Jan 30, 9:35Â*am, uj <andrey.balag...@newsgroup> wrote:

> On Jan 29, 9:55Â*pm, stej <cerna.ze...@newsgroup> wrote:
>

> > Could je publish somewhere the files to examine them?

>
> Here's archive with excerpts of both snapshot (top 100-something
> lines, a.txt and b.txt), output of compare-object, and output of UNIX
> diff (unified). All files are UTF-8:
>
> http://91.204.198.27/compare-object-problem.zip
>
> --
> Best Regards, Andrey Balaguta

To see too :
Compare-Object gotcha « Dmitry’s PowerBlog: PowerShell and beyond

On Jan 30, 10:47*pm, stej <cerna.ze...@newsgroup> wrote:

> It looks ok. I have no idea what is going on there on your computer.
> What versions ov PowerShell do you use? V2?

Well, that's weird. Yes, I'm using PowerShell V2 CTP. I don't know how
our versions could differ, I have PSCX on my machine installed, but
I've tried running powershell -NoProfile (so I think it pretty much
'vanilla') and I still get the same results.

--
Best Regards, Andrey Balaguta