Vista - Mysterious empty line in DateTime formatting

Can somebody explain why there is an empty line added in the first example?

#########################
# Get-DateTimeFormatBug.ps1
#########################
" `n`n`n example 1"
"---"
[DateTime]"03-mar-2006"
"---"
[DateTime]"03-mar-2006"
[DateTime]"03-mar-2006"
"---"


" `n`n`n example 2"
"---"
[DateTime]::Now
"---"
[DateTime]::Now
[DateTime]::Now
"---"
#########################



--
greetings
dreeschkind

To be more clear, this is the output that I see when running that script:
Note the added empty line in example one:


example 1
---
<<<<<< this is the added empty line that should not be there
Freitag, 3. März 2006 00:00:00
---
Freitag, 3. März 2006 00:00:00
Freitag, 3. März 2006 00:00:00
---





example 2
---
Samstag, 2. September 2006 22:37:15
---
Samstag, 2. September 2006 22:37:15
Samstag, 2. September 2006 22:37:15
---



--
greetings
dreeschkind

"dreeschkind" wrote:

> Can somebody explain why there is an empty line added in the first example?
>
> #########################
> # Get-DateTimeFormatBug.ps1
> #########################
> " `n`n`n example 1"
> "---"
> [DateTime]"03-mar-2006"
> "---"
> [DateTime]"03-mar-2006"
> [DateTime]"03-mar-2006"
> "---"
>
>
> " `n`n`n example 2"
> "---"
> [DateTime]::Now
> "---"
> [DateTime]::Now
> [DateTime]::Now
> "---"
> #########################
>
>
>
> --
> greetings
> dreeschkind

dreeschkind wrote:
> Can somebody explain why there is an empty line added in the first example?
>
> #########################
> # Get-DateTimeFormatBug.ps1
> #########################
> " `n`n`n example 1"
> "---"
> [DateTime]"03-mar-2006"
> "---"
> [DateTime]"03-mar-2006"
> [DateTime]"03-mar-2006"
> "---"
>
>
> " `n`n`n example 2"
> "---"
> [DateTime]::Now
> "---"
> [DateTime]::Now
> [DateTime]::Now
> "---"
> #########################
>
>
>
> --
> greetings
> dreeschkind

Interesting. In PowerShell Analyzer output window there is no extra
line, but straight from the shell I am seeing the same as you.

I'm pretty sure this was talked about a long time ago, and has to do with
the way that the formatter does it's business. What's really happening is
that the formatter has been given a couple of different types of objects,
and it does its best to format them. Let's take a closer look at this
example: We actually only need the first three lines:

"---"
get-date
"---"

so, this gets sent to the formatter as an array of three objects,
[string],[datetime],[string]. The formatter lets strings and numbers
straight through, so we get:
---

next, we get a datetime object and since it's the first non-value type
through the formatter, an attempt is made to format it (which adds a CR
upfront to make it "pretty"), so we get
<empty line>
Monday, September 04, 2006 1:55:57 PM
lastly, we have another string, which just goes on through
---
<empty line>
<empty line>

so, that extra newline at the beginning is a result of the formatter trying
to make it "pretty". This behavior is even more noticable when different
non-value type objects are piped. The reason that the "pretty" 2 empty
lines don't follow the date is because another object is thrown at the
formatter (that last string), but you can see the 2 empty lines after all
the "real" output. The reason that you don't get the same newline before
the other date objects is that it's the same type that comes at the
formatter - we can show this:
Take the following (which you could either script or put on the same command
line as I'm about to do):

PS> get-date;ps idle

Monday, September 04, 2006 2:00:34 PM

Id : 0
Handles : 0
CPU :
Name : Idle

The pipeline is grabbed by the host and the formatter (out-default) is added
to the entire command line (*not* formatting for each element in the
pipeline - the host doesn't know anything about the language parsing, so
doesn't even really know what was typed). The formatting is done by the host
when the user doesn't specify a format and the first object wins the battle
on what the formatting should be. That's why the process object is
formatted as a list - the shell doesn't want to throw the data away, but it
can't format the process object like a date, so you get a list view _and_
another blank line (since the formatter stepped in).

There are a couple of ways to solve this, they require turning the output
into strings and you either have to manage your own formatting, or convert
the shell formatting into strings and use those, here's an example:

"---"
get-date|out-string -stream|?{$_}
"---"

when run, you get:
PS> c:\temp\t5
---
Monday, September 04, 2006 2:09:45 PM
---

The interesting line is the pipeline, out-string -stream converts the
formatting into an array of strings and the ?{$_} only allows those strings
that are non-empty through.

hope that helps

--
James Truher[MSFT]
Program Manager - Windows PowerShell
Microsoft Corporation
This posting is provided "AS IS" with no warranties, no confers rights.
Visit the Windows PowerShell Team blog at:
http://blogs.msdn.com/PowerShell
Visit the Windows PowerShell ScriptCenter at:
http://www.microsoft.com/technet/scr.../hubs/msh.mspx
"dreeschkind" <dreeschkind@discussions.microsoft.com> wrote in message
news:6C12FF3A-7C79-4770-BA34-122FCE2BF611@microsoft.com...
> Can somebody explain why there is an empty line added in the first
> example?
>
> #########################
> # Get-DateTimeFormatBug.ps1
> #########################
> " `n`n`n example 1"
> "---"
> [DateTime]"03-mar-2006"
> "---"
> [DateTime]"03-mar-2006"
> [DateTime]"03-mar-2006"
> "---"
>
>
> " `n`n`n example 2"
> "---"
> [DateTime]::Now
> "---"
> [DateTime]::Now
> [DateTime]::Now
> "---"
> #########################
>
>
>
> --
> greetings
> dreeschkind

"James Truher" wrote:

> I'm pretty sure this was talked about a long time ago, and has to do with
> the way that the formatter does it's business.

We had a little discussion about this issue in the IRC channel #powershell
on freenode yesterday. And even though Jeffrey dedicated two of his articles
on that topic on the blog, it still seems that formatting is not always
comprehensible.

> What's really happening is
> that the formatter has been given a couple of different types of objects,
> and it does its best to format them. Let's take a closer look at this
> example: We actually only need the first three lines:
>
> "---"
> get-date
> "---"
>
> so, this gets sent to the formatter as an array of three objects,
> [string],[datetime],[string]. The formatter lets strings and numbers
> straight through, so we get:
> ---
>
> next, we get a datetime object and since it's the first non-value type
> through the formatter, an attempt is made to format it (which adds a CR
> upfront to make it "pretty"), so we get
> <empty line>
> Monday, September 04, 2006 1:55:57 PM
> lastly, we have another string, which just goes on through
> ---
> <empty line>
> <empty line>
>
> so, that extra newline at the beginning is a result of the formatter trying
> to make it "pretty". This behavior is even more noticable when different
> non-value type objects are piped. The reason that the "pretty" 2 empty
> lines don't follow the date is because another object is thrown at the
> formatter (that last string), but you can see the 2 empty lines after all
> the "real" output. The reason that you don't get the same newline before
> the other date objects is that it's the same type that comes at the
> formatter - we can show this:

If I understand you correctly, the same thing is happening in the following
example.
PowerShell adds table header etc. to make the first file object "pretty".
What I don't understand, why doesn't PowerShell repeat the "pretty" header
(or a single newline in case of the datetime object) after the string ("---").

PS> gci; "----foo---"; gci

Directory: Microsoft.PowerShell.Core\FileSystem::C:\test

Mode LastWriteTime Length Name
---- ------------- ------ ----
-a--- 04.09.2006 22:57 46 test.bak
-a--- 04.09.2006 23:06 42 test.txt
----foo---
-a--- 04.09.2006 22:57 46 test.bak
-a--- 04.09.2006 23:06 42 test.txt

> Take the following (which you could either script or put on the same command
> line as I'm about to do):
>
> PS> get-date;ps idle
>
> Monday, September 04, 2006 2:00:34 PM
>
> Id : 0
> Handles : 0
> CPU :
> Name : Idle
>
> The pipeline is grabbed by the host and the formatter (out-default) is added
> to the entire command line (*not* formatting for each element in the
> pipeline - the host doesn't know anything about the language parsing, so
> doesn't even really know what was typed). The formatting is done by the host
> when the user doesn't specify a format and the first object wins the battle
> on what the formatting should be. That's why the process object is
> formatted as a list - the shell doesn't want to throw the data away, but it
> can't format the process object like a date, so you get a list view _and_
> another blank line (since the formatter stepped in).

I'm sure there is a lot of thought behind they way the formatter works, but
I'm not sure wheather this is the best solution. The workaround that you
recommend using may work, but IMHO plain text formatting should be made more
simple and not be that complicated and obscuring.

> There are a couple of ways to solve this, they require turning the output
> into strings and you either have to manage your own formatting, or convert
> the shell formatting into strings and use those, here's an example:
>
> "---"
> get-date|out-string -stream|?{$_}
> "---"
>
> when run, you get:
> PS> c:\temp\t5
> ---
> Monday, September 04, 2006 2:09:45 PM
> ---
>
> The interesting line is the pipeline, out-string -stream converts the
> formatting into an array of strings and the ?{$_} only allows those strings
> that are non-empty through.
>
> hope that helps

I hope user feedback helps...

--
greetings
dreeschkind

> --
> James Truher[MSFT]
> Program Manager - Windows PowerShell
> Microsoft Corporation
> This posting is provided "AS IS" with no warranties, no confers rights.
> Visit the Windows PowerShell Team blog at:
> http://blogs.msdn.com/PowerShell
> Visit the Windows PowerShell ScriptCenter at:
> http://www.microsoft.com/technet/scr.../hubs/msh.mspx
> "dreeschkind" <dreeschkind@discussions.microsoft.com> wrote in message
> news:6C12FF3A-7C79-4770-BA34-122FCE2BF611@microsoft.com...
> > Can somebody explain why there is an empty line added in the first
> > example?
> >
> > #########################
> > # Get-DateTimeFormatBug.ps1
> > #########################
> > " `n`n`n example 1"
> > "---"
> > [DateTime]"03-mar-2006"
> > "---"
> > [DateTime]"03-mar-2006"
> > [DateTime]"03-mar-2006"
> > "---"
> >
> >
> > " `n`n`n example 2"
> > "---"
> > [DateTime]::Now
> > "---"
> > [DateTime]::Now
> > [DateTime]::Now
> > "---"
> > #########################
> >
> >
> >
> > --
> > greetings
> > dreeschkind
>
>
>

James Truher wrote:
> ... next, we get a datetime object and since it's the first non-value type
> through the formatter, an attempt is made to format it (which adds a CR
> upfront to make it "pretty"), so we get ...

Hmm, I tend to think that it should do less guessing and be more
consistent. Then, the user can insert that blank line if he/she wants it...

the reason that powershell doesn't add the new line in this case
gci;"---foo---";gci
is that the string "---foo---" doesn't affect the state of the formatter, it
just gets passed through. The formatter knows that it was emitting file/dir
info objects so when it gets another one of those (after the "---foo---") no
new formatting is needed - it just takes up where it left off.

jim

--
James Truher[MSFT]
Program Manager - Windows PowerShell
Microsoft Corporation
This posting is provided "AS IS" with no warranties, no confers rights.
Visit the Windows PowerShell Team blog at:
http://blogs.msdn.com/PowerShell
Visit the Windows PowerShell ScriptCenter at:
http://www.microsoft.com/technet/scr.../hubs/msh.mspx
"dreeschkind" <dreeschkind@discussions.microsoft.com> wrote in message
news:B2DB5C2A-267C-4ED5-81BD-7B2D14582607@microsoft.com...
> "James Truher" wrote:
>
>> I'm pretty sure this was talked about a long time ago, and has to do with
>> the way that the formatter does it's business.
>
> We had a little discussion about this issue in the IRC channel #powershell
> on freenode yesterday. And even though Jeffrey dedicated two of his
> articles
> on that topic on the blog, it still seems that formatting is not always
> comprehensible.
>
>> What's really happening is
>> that the formatter has been given a couple of different types of objects,
>> and it does its best to format them. Let's take a closer look at this
>> example: We actually only need the first three lines:
>>
>> "---"
>> get-date
>> "---"
>>
>> so, this gets sent to the formatter as an array of three objects,
>> [string],[datetime],[string]. The formatter lets strings and numbers
>> straight through, so we get:
>> ---
>>
>> next, we get a datetime object and since it's the first non-value type
>> through the formatter, an attempt is made to format it (which adds a CR
>> upfront to make it "pretty"), so we get
>> <empty line>
>> Monday, September 04, 2006 1:55:57 PM
>> lastly, we have another string, which just goes on through
>> ---
>> <empty line>
>> <empty line>
>>
>> so, that extra newline at the beginning is a result of the formatter
>> trying
>> to make it "pretty". This behavior is even more noticable when different
>> non-value type objects are piped. The reason that the "pretty" 2 empty
>> lines don't follow the date is because another object is thrown at the
>> formatter (that last string), but you can see the 2 empty lines after all
>> the "real" output. The reason that you don't get the same newline
>> before
>> the other date objects is that it's the same type that comes at the
>> formatter - we can show this:
>
> If I understand you correctly, the same thing is happening in the
> following
> example.
> PowerShell adds table header etc. to make the first file object "pretty".
> What I don't understand, why doesn't PowerShell repeat the "pretty" header
> (or a single newline in case of the datetime object) after the string
> ("---").
>
> PS> gci; "----foo---"; gci
>
> Directory: Microsoft.PowerShell.Core\FileSystem::C:\test
>
> Mode LastWriteTime Length Name
> ---- ------------- ------ ----
> -a--- 04.09.2006 22:57 46 test.bak
> -a--- 04.09.2006 23:06 42 test.txt
> ----foo---
> -a--- 04.09.2006 22:57 46 test.bak
> -a--- 04.09.2006 23:06 42 test.txt
>
>> Take the following (which you could either script or put on the same
>> command
>> line as I'm about to do):
>>
>> PS> get-date;ps idle
>>
>> Monday, September 04, 2006 2:00:34 PM
>>
>> Id : 0
>> Handles : 0
>> CPU :
>> Name : Idle
>>
>> The pipeline is grabbed by the host and the formatter (out-default) is
>> added
>> to the entire command line (*not* formatting for each element in the
>> pipeline - the host doesn't know anything about the language parsing, so
>> doesn't even really know what was typed). The formatting is done by the
>> host
>> when the user doesn't specify a format and the first object wins the
>> battle
>> on what the formatting should be. That's why the process object is
>> formatted as a list - the shell doesn't want to throw the data away, but
>> it
>> can't format the process object like a date, so you get a list view _and_
>> another blank line (since the formatter stepped in).
>
> I'm sure there is a lot of thought behind they way the formatter works,
> but
> I'm not sure wheather this is the best solution. The workaround that you
> recommend using may work, but IMHO plain text formatting should be made
> more
> simple and not be that complicated and obscuring.
>
>> There are a couple of ways to solve this, they require turning the output
>> into strings and you either have to manage your own formatting, or
>> convert
>> the shell formatting into strings and use those, here's an example:
>>
>> "---"
>> get-date|out-string -stream|?{$_}
>> "---"
>>
>> when run, you get:
>> PS> c:\temp\t5
>> ---
>> Monday, September 04, 2006 2:09:45 PM
>> ---
>>
>> The interesting line is the pipeline, out-string -stream converts the
>> formatting into an array of strings and the ?{$_} only allows those
>> strings
>> that are non-empty through.
>>
>> hope that helps
>
> I hope user feedback helps...
>
> --
> greetings
> dreeschkind
>
>> --
>> James Truher[MSFT]
>> Program Manager - Windows PowerShell
>> Microsoft Corporation
>> This posting is provided "AS IS" with no warranties, no confers rights.
>> Visit the Windows PowerShell Team blog at:
>> http://blogs.msdn.com/PowerShell
>> Visit the Windows PowerShell ScriptCenter at:
>> http://www.microsoft.com/technet/scr.../hubs/msh.mspx
>> "dreeschkind" <dreeschkind@discussions.microsoft.com> wrote in message
>> news:6C12FF3A-7C79-4770-BA34-122FCE2BF611@microsoft.com...
>> > Can somebody explain why there is an empty line added in the first
>> > example?
>> >
>> > #########################
>> > # Get-DateTimeFormatBug.ps1
>> > #########################
>> > " `n`n`n example 1"
>> > "---"
>> > [DateTime]"03-mar-2006"
>> > "---"
>> > [DateTime]"03-mar-2006"
>> > [DateTime]"03-mar-2006"
>> > "---"
>> >
>> >
>> > " `n`n`n example 2"
>> > "---"
>> > [DateTime]::Now
>> > "---"
>> > [DateTime]::Now
>> > [DateTime]::Now
>> > "---"
>> > #########################
>> >
>> >
>> >
>> > --
>> > greetings
>> > dreeschkind
>>
>>
>>

"James Truher" wrote:

> the reason that powershell doesn't add the new line in this case
> gci;"---foo---";gci
> is that the string "---foo---" doesn't affect the state of the formatter, it
> just gets passed through.

Then maybe it should affect the state of the formatter?

> The formatter knows that it was emitting file/dir
> info objects so when it gets another one of those (after the "---foo---") no
> new formatting is needed - it just takes up where it left off.

How can the formater be sure that no new formatting is needed?
As Adam Milazzo put it:
"I tend to think that it should do less guessing and be more consistent."

Can't the formatter just switch it's formatting state when new objects arive?
I understand that printing the String object "---" doesn't need a pretty
object header, but when the next group of File or Process objects arives it
should probably get it's individual pretty formatting again regardless of
what was before.

Same as in the next example, the formatter can't print the Process objects
as a table, just because a group of File objects have been printed before.
This is odd.

PS> gci; gps; gci


But never mind, PowerShell seriously is a great product so far and
I hope V2 will get an big overhaul so it will be even better than that.

--
greetings
dreeschkind

> jim
>
> --
> James Truher[MSFT]
> Program Manager - Windows PowerShell
> Microsoft Corporation
> This posting is provided "AS IS" with no warranties, no confers rights.
> Visit the Windows PowerShell Team blog at:
> http://blogs.msdn.com/PowerShell
> Visit the Windows PowerShell ScriptCenter at:
> http://www.microsoft.com/technet/scr.../hubs/msh.mspx
> "dreeschkind" <dreeschkind@discussions.microsoft.com> wrote in message
> news:B2DB5C2A-267C-4ED5-81BD-7B2D14582607@microsoft.com...
> > "James Truher" wrote:
> >
> >> I'm pretty sure this was talked about a long time ago, and has to do with
> >> the way that the formatter does it's business.
> >
> > We had a little discussion about this issue in the IRC channel #powershell
> > on freenode yesterday. And even though Jeffrey dedicated two of his
> > articles
> > on that topic on the blog, it still seems that formatting is not always
> > comprehensible.
> >
> >> What's really happening is
> >> that the formatter has been given a couple of different types of objects,
> >> and it does its best to format them. Let's take a closer look at this
> >> example: We actually only need the first three lines:
> >>
> >> "---"
> >> get-date
> >> "---"
> >>
> >> so, this gets sent to the formatter as an array of three objects,
> >> [string],[datetime],[string]. The formatter lets strings and numbers
> >> straight through, so we get:
> >> ---
> >>
> >> next, we get a datetime object and since it's the first non-value type
> >> through the formatter, an attempt is made to format it (which adds a CR
> >> upfront to make it "pretty"), so we get
> >> <empty line>
> >> Monday, September 04, 2006 1:55:57 PM
> >> lastly, we have another string, which just goes on through
> >> ---
> >> <empty line>
> >> <empty line>
> >>
> >> so, that extra newline at the beginning is a result of the formatter
> >> trying
> >> to make it "pretty". This behavior is even more noticable when different
> >> non-value type objects are piped. The reason that the "pretty" 2 empty
> >> lines don't follow the date is because another object is thrown at the
> >> formatter (that last string), but you can see the 2 empty lines after all
> >> the "real" output. The reason that you don't get the same newline
> >> before
> >> the other date objects is that it's the same type that comes at the
> >> formatter - we can show this:
> >
> > If I understand you correctly, the same thing is happening in the
> > following
> > example.
> > PowerShell adds table header etc. to make the first file object "pretty".
> > What I don't understand, why doesn't PowerShell repeat the "pretty" header
> > (or a single newline in case of the datetime object) after the string
> > ("---").
> >
> > PS> gci; "----foo---"; gci
> >
> > Directory: Microsoft.PowerShell.Core\FileSystem::C:\test
> >
> > Mode LastWriteTime Length Name
> > ---- ------------- ------ ----
> > -a--- 04.09.2006 22:57 46 test.bak
> > -a--- 04.09.2006 23:06 42 test.txt
> > ----foo---
> > -a--- 04.09.2006 22:57 46 test.bak
> > -a--- 04.09.2006 23:06 42 test.txt
> >
> >> Take the following (which you could either script or put on the same
> >> command
> >> line as I'm about to do):
> >>
> >> PS> get-date;ps idle
> >>
> >> Monday, September 04, 2006 2:00:34 PM
> >>
> >> Id : 0
> >> Handles : 0
> >> CPU :
> >> Name : Idle
> >>
> >> The pipeline is grabbed by the host and the formatter (out-default) is
> >> added
> >> to the entire command line (*not* formatting for each element in the
> >> pipeline - the host doesn't know anything about the language parsing, so
> >> doesn't even really know what was typed). The formatting is done by the
> >> host
> >> when the user doesn't specify a format and the first object wins the
> >> battle
> >> on what the formatting should be. That's why the process object is
> >> formatted as a list - the shell doesn't want to throw the data away, but
> >> it
> >> can't format the process object like a date, so you get a list view _and_
> >> another blank line (since the formatter stepped in).
> >
> > I'm sure there is a lot of thought behind they way the formatter works,
> > but
> > I'm not sure wheather this is the best solution. The workaround that you
> > recommend using may work, but IMHO plain text formatting should be made
> > more
> > simple and not be that complicated and obscuring.
> >
> >> There are a couple of ways to solve this, they require turning the output
> >> into strings and you either have to manage your own formatting, or
> >> convert
> >> the shell formatting into strings and use those, here's an example:
> >>
> >> "---"
> >> get-date|out-string -stream|?{$_}
> >> "---"
> >>
> >> when run, you get:
> >> PS> c:\temp\t5
> >> ---
> >> Monday, September 04, 2006 2:09:45 PM
> >> ---
> >>
> >> The interesting line is the pipeline, out-string -stream converts the
> >> formatting into an array of strings and the ?{$_} only allows those
> >> strings
> >> that are non-empty through.
> >>
> >> hope that helps
> >
> > I hope user feedback helps...
> >
> > --
> > greetings
> > dreeschkind
> >
> >> --
> >> James Truher[MSFT]
> >> Program Manager - Windows PowerShell
> >> Microsoft Corporation
> >> This posting is provided "AS IS" with no warranties, no confers rights.
> >> Visit the Windows PowerShell Team blog at:
> >> http://blogs.msdn.com/PowerShell
> >> Visit the Windows PowerShell ScriptCenter at:
> >> http://www.microsoft.com/technet/scr.../hubs/msh.mspx
> >> "dreeschkind" <dreeschkind@discussions.microsoft.com> wrote in message
> >> news:6C12FF3A-7C79-4770-BA34-122FCE2BF611@microsoft.com...
> >> > Can somebody explain why there is an empty line added in the first
> >> > example?
> >> >
> >> > #########################
> >> > # Get-DateTimeFormatBug.ps1
> >> > #########################
> >> > " `n`n`n example 1"
> >> > "---"
> >> > [DateTime]"03-mar-2006"
> >> > "---"
> >> > [DateTime]"03-mar-2006"
> >> > [DateTime]"03-mar-2006"
> >> > "---"
> >> >
> >> >
> >> > " `n`n`n example 2"
> >> > "---"
> >> > [DateTime]::Now
> >> > "---"
> >> > [DateTime]::Now
> >> > [DateTime]::Now
> >> > "---"
> >> > #########################
> >> >
> >> >
> >> >
> >> > --
> >> > greetings
> >> > dreeschkind
> >>
> >>
> >>
>
>
>

>Can't the formatter just switch it's formatting state when new >objects
>arive?
>I understand that printing the String object "---" doesn't need a pretty
>object header, but when the next group of File or Process objects arives it
>should probably get it's individual pretty formatting again regardless of
>what was before.

the grouping is the important thing here.
where there is a different type, not expected as part of the grouping, its
going to close the group, then go onto format whatever it is getting in the
pipeline from then on.