How to avoid an UnathorizedAccessException when using Get-ChildItem? - powershell

Question

I am using PowerShell 5.0 and working on a script to find and list all the versions of log4net.dll under the current directory recursively.
Get-ChildItem log4net.dll -Recurse | % versioninfo | Export-Csv "C:\MyJunk\log4net.csv"
The above statement begins returning version information as expected but execution stops at the first folder I lack permission to access:
Get-ChildItem : The specified network name is no longer available.
At line:1 char:1
+ Get-ChildItem log4net.dll -Recurse | % versioninfo | Export-Csv "C:\M ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : ReadError: (J:\ArcPlan_OracleWallet\Production:String) [Get-ChildItem], IOException
+ FullyQualifiedErrorId : DirIOError,Microsoft.PowerShell.Commands.GetChildItemCommand
Get-ChildItem : Access is denied
At line:1 char:1
+ Get-ChildItem log4net.dll -Recurse | % versioninfo | Export-Csv "C:\M ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : NotSpecified: (:) [Get-ChildItem], UnauthorizedAccessException
+ FullyQualifiedErrorId : System.UnauthorizedAccessException,Microsoft.PowerShell.Commands.GetChildItemCommand
I am running Windows PowerShell ISE as Adminstrator. ExecutionPolicy is RemoteSigned and $ErrorActionPreference is Continue.
Ideally I would like the script to interrogate each folder's ACL and bypass all folders (and their contents) I lack permission to access. However another solution would one in which hard-coded folders are bypassed. Being a novice in PowerShell I focused on the later.
I have tried bypassing the first problem folder (by name) to see if I could get that working, but encounter the same exception and processing stops.
Get-ChildItem log4net.dll -Recurse | Where-Object { $_.FullName -notmatch '\\ArcPlan_OracleWallet\\?'} | export-csv 'C:\MyJunk\log4net.csv'
Thanks.

Answer 1

If you want to ignore the errors, use -ErrorAction SilentlyContinue.
There are other useful values to this parameter, as you can discover here and here.
Here is a nice question quite on-topic.
You can also fetch help about this with Get-Help about_CommonParameters.
(Hi and welcome, if you dig this answer, read this ^^).

Answer 2

I believe the issue was that the Get-ChildItem log4net.dll -Recurse would fail before the Where-Object could filter out the unwanted directories.
I want to avoid hard-coding directories, but here is my (klunky) solution so far.
## Version information will be retrieved for $fileName
$fileName = 'log4net.dll'
$ErrorActionPreference = 'Continue'
## Get directies - excluding those you lack permission to access
$directories = Get-ChildItem -Directory |
Where-Object {$_.FullName -inotmatch 'directory-1' -and
$_.FullName -inotmatch 'directory-2' -and
$_.FullName -inotmatch 'directory-3'
}
## Array to hold version information
$allFilesVersionInfo = #()
foreach ($directory in $directories) {
## Get all files recursively
$files = Get-ChildItem -Path $directory.FullName $fileName -Recurse
foreach ($file in $files) {
## Get version information and add to array
$fileVersionInfo = $file | % versioninfo
$allFilesVersionInfo += $fileVersionInfo
}
}
# Write version information in arra to file
$exportFullPath = "C:\MyJunk\$($fileName)-version.csv"
$allFilesVersionInfo | Export-Csv -Path $($exportFullPath)