PowerShell - searching for existing files generates empty output - powershell

Question

I wish to search for specific files listed in searchFiles and pipe their locations to TestFileLocation.CSV. However, my current script only generates an empty CSV. What am I missing?
My TestFindFile.csv is of the form:
Name
123.pdf
321.pdf
aaa.pdf
SNIPPET
$searchFiles = Import-CSV 'C:\Data\SCRIPTS\PS1\TestFindFile.csv' -Header ("Name")
$source = 'C:\Data'
ForEach($File in $searchFiles)
{
Get-ChildItem $source -Filter $File -rec | where {!$_.PSIsContainer} | select-object FullName | export-csv -notypeinformation -delimiter '|' -path c:\data\scripts\ps1\TestFileLocation.csv
}

Answer 1

You were overwriting the CSV for each iteration of the loop.
$searchFiles = Import-CSV 'C:\Data\SCRIPTS\PS1\TestFindFile.csv' -Header ("Name")
$source = 'C:\Data'
$outputPath = 'c:\data\scripts\ps1\TestFileLocation.csv'
$searchFiles | ForEach-Object {
# Silently continue to try to ignore error like
# not being able to read path's which are too long
Get-ChildItem $source -Filter $_ -rec -ErrorAction SilentlyContinue | where {!$_.PSIsContainer} | select-object FullName
} | export-csv -notypeinformation -delimiter '|' -path $outputPath
Example using AlphaFS
A comment asked for an example using AlphaFS because it claims to overcome the long path issue. I'm not going into all the details, but here is how I got it to work.
# download and unzip to c:\alpahfs
# dir C:\AlphaFS\* -Recurse -File | Unblock-File
[System.Reflection.Assembly]::LoadFrom('C:\AlphaFS\lib\net451\AlphaFS.dll')
$searchFiles = Import-CSV 'C:\Data\SCRIPTS\PS1\TestFindFile.csv' -Header ("Name")
$source = 'C:\Data'
$outputPath = 'c:\data\scripts\ps1\TestFileLocation.csv'
$searchFiles | ForEach-Object {
$files = [Alphaleonis.Win32.Filesystem.Directory]::EnumerateFiles($source,'*',[System.IO.SearchOption]::AllDirectories)
$files | ForEach-Object { [PSCustomObject] #{FileName = $_} }
} | export-csv -notypeinformation -delimiter '|' -path $outputPath
# type $outputPath

Answer 2

If your .csv file contains the header "Name", there is no need to again declare it when running Import-Csv.
The reason the output is empty is that you are searching for an Object which contains the property Name (imported from the TestFindFile.csv). Search for $File.Name. Also pull commands outside the loop that don't need to be there:
$searchFiles | Select -ExpandProperty Name | % {
Get-ChildItem $source -Filter $_ -Recurse | where {!$_.PSIsContainer}
} | select-object FullName | export-csv -notypeinformation -delimiter '|' -path c:\data\scripts\ps1\TestFileLocation.csv