Get-Item fails with closed pipeline error - powershell

Question

If I have an example function ...
function foo()
{
# get a list of files matched pattern and timestamp
$fs = Get-Item -Path "C:\Temp\*.txt"
| Where-Object {$_.lastwritetime -gt "11/01/2009"}
if ( $fs -ne $null ) # $fs may be empty, check it first
{
foreach ($o in $fs)
{
# new bak file
$fBack = "C:\Temp\test\" + $o.Name + ".bak"
# Exception here Get-Item! See following msg
# Exception thrown only Get-Item cannot find any files this time.
# If there is any matched file there, it is OK
$fs1 = Get-Item -Path $fBack
....
}
}
}
The exception message is ... The WriteObject and WriteError methods cannot be called after the pipeline has been closed. Please contact Microsoft Support Services.
Basically, I cannot use Get-Item again within the function or loop to get a list of files in a different folder.
Any explanation and what is the correct way to fix it?
By the way I am using PS 1.0.

Answer 1

This is just a minor variation of what has already been suggested, but it uses some techniques that make the code a bit simpler ...
function foo()
{
# Get a list of files matched pattern and timestamp
$fs = #(Get-Item C:\Temp\*.txt | Where {$_.lastwritetime -gt "11/01/2009"})
foreach ($o in $fs) {
# new bak file
$fBack = "C:\Temp\test\$($o.Name).bak"
if (!(Test-Path $fBack))
{
Copy-Item $fs.Fullname $fBack
}
$fs1 = Get-Item -Path $fBack
....
}
}
For more info on the issue with foreach and scalar null values check out this blog post.

Answer 2

I modified the above code slightly to create the backup file, but I am able to use the Get-Item within the loop successfully, with no exceptions being thrown. My code is:
function foo()
{
# get a list of files matched pattern and timestamp
$files = Get-Item -Path "C:\Temp\*.*" | Where-Object {$_.lastwritetime -gt "11/01/2009"}
foreach ($file in $files)
{
$fileBackup = [string]::Format("{0}{1}{2}", "C:\Temp\Test\", $file.Name , ".bak")
Copy-Item $file.FullName -destination $fileBackup
# Test that backup file exists
if (!(Test-Path $fileBackup))
{
Write-Host "$fileBackup does not exist!"
}
else
{
$fs1 = Get-Item -Path $fileBackup
...
}
}
}
I am also using PowerShell 1.0.