PowerShell: Catch Exception of Active Directory Cmdlets

Question

I have a problem concerning Exceptions in Powershell. For some reason they don't get caught.

Try { 
    Add-ADGroupMember -Identity $GroupToModify.ObjectGUID -Members $user
} Catch [ADIdentityNotFoundException] {
    #message goes here
}

when trying to add a user from a different Domain it outputs:

Get-ADUser : Cannot find an object with identity: 'CN=user,OU=users,
OU=J2,OU=sites,DC=asia,DC=domain,DC=com' under: 'DC=europe,
DC=domain,DC=com'.
At myscript.ps1:753 char:14
+     $adMember = Get-ADUser $user
+                 ~~~~~~~~~~~~~~~~
+ CategoryInfo          : ObjectNotFound: (CN=user...s,DC=com:ADUser) 
[Get-ADUser], ADIdentityNotFoundException
+FullyQualifiedErrorId :
ActiveDirectoryCmdlet:
Microsoft.ActiveDirectory.Management.ADIdentityNotFoundException,
Microsoft.ActiveDirectory.Management.Commands.GetADUser

Answer 1

You have 2 options. Use -ErrorAction Stop on each cmdlet you want to trigger an exception:

Try { 
    Add-ADGroupMember -Identity $GroupToModify.ObjectGUID -Members $user -ErrorAction Stop
} Catch [ADIdentityNotFoundException] {
    #message goes here
}

or specify $ErrorActionPreference = "Stop" at beginning of PS session to achieve same result for all subsequent cmdlets.

Answer 2

Check out this error handling guide from Hey Scripting guy, it really helped me understand ho to use catch statements. http://blogs.technet.com/b/heyscriptingguy/archive/2010/03/11/hey-scripting-guy-march-11-2010.aspx