Vista - Deleting old files

Is there a command to delete all files in a directory that are more than
three days old?

Any help is greatly appreciated.

gci "c:\somedir\*.*" |? {$_.lastwritetime -lt (get-date).adddays(-3)} |
remove-item -whatif


I'd run it with the -whatif first, and if it looks right, take it off and
re-run.

"Greg" wrote:

Do filters like that have to consider a potential execution span that starts
before midnight and finishes after midnight and get coded as below?

$purgedate = (get-date).adddays(-3)
gci "c:\somedir\*.*" | ? {$_.lastwritetime -lt $purgedate}

- Larry


Rob Campbell wrote:

Before or after midnight won't matter. The filter will evaluate whether the
timespan between the lastwritetime and the current datetime is more than 3
days (or 72 hours, or 4320 minutes......).

"Larry__Weiss" wrote:

Then that might not be what is needed.
I would expect that one would just want calendar days age,
and that the age calculation not be dependent on how much
of the current day has already expired.

That aside, what I was really wanting to know was is the filter
criteria evaluated one time only, or evaluated again and again
as each item is presented for filtering?

- Larry


Rob Campbell wrote:

I believe it's evaluated for each file as it passes through the pipeline.

On the side note, a quick way to do that kind of calendar day math is:

if ([int]$_.lastwritetime.tooadate() -lt [int](get-date).tooadate() -3){ri $_}

"Larry__Weiss" wrote:

from:
http://msdn.microsoft.com/en-us/libr....tooadate.aspx
..NET Framework Class Library
DateTime..::.ToOADate Method
Converts the value of this instance to the equivalent OLE Automation date.

from:
http://blogs.msdn.com/oldnewthing/ar.../05/54806.aspx
The OLE automation date format is a floating point value, counting days since
midnight 30 December 1899. Hours and minutes are represented as fractional days.

Since PowerShell rounds to nearest int when converting float to integer, won't
that make the filter still be sensitive to current time of day the way you have
coded it?
http://www.johndcook.com/blog/2008/0...in-powershell/

- Larry



Rob Campbell wrote:

Then I'd want to save off anything like an offset date that I'd want to
consistently apply to all items while filtering.

- Larry

Rob Campbell wrote:

You're right. Run it close enough to midnight and throw enough files at it,
and it's probably going to break.


"Larry__Weiss" wrote: