User Get-ADUser to list all properties and export to .csv - powershell

Question

I'm trying to go through a list of users I have and would like to get a few properties (DisplayName, Office) to show in a table then convert the table to a .csv.
I've been working with:
$Users = gc "C:\scripts\Users.txt
foreach ($User in $Users) {
Get-ADUser -Identity $User -Properties DisplayName,Office
}
And that's fine, I can combine it with "select DisplayName,Office" but if I do an "Out-File -append" it just looks terrible. I think I should do this with an array or hash table but I've been reading up on them and don't really understand how I would automate one that can be exported. Thanks for any help you can provide.

Answer 1

Query all users and filter by the list from your text file:
$Users = Get-Content 'C:\scripts\Users.txt'
Get-ADUser -Filter '*' -Properties DisplayName,Office |
Where-Object { $Users -contains $_.SamAccountName } |
Select-Object DisplayName, Office |
Export-Csv 'C:\path\to\your.csv' -NoType
Get-ADUser -Filter '*' returns all AD user accounts. This stream of user objects is then piped into a Where-Object filter, which checks for each object if its SamAccountName property is contained in the user list from your input file ($Users). Only objects with a matching account name are passed forward to the next step of the pipeline. The output can be limited by selecting the relevant properties before exporting the data.
You can further optimize the code by replacing the -contains operator with hashtable lookups:
$Users = #{}
Get-Content 'C:\scripts\Users.txt' | ForEach-Object { $Users[$_] = $true }
Get-ADUser -Filter '*' -Properties DisplayName,Office |
Where-Object { $Users.ContainsKey($_.SamAccountName) } |
Select-Object DisplayName, Office |
Export-Csv 'C:\path\to\your.csv' -NoType

Answer 2

This can be simplified by completely skipping the where object and the $users declaration. All you need is:
Code
get-content c:\scripts\users.txt | get-aduser -properties * | select displayname, office | export-csv c:\path\to\your.csv

Answer 3

#AnsgarWiechers - it's not my experience that querying everything and then pruning the result is more efficient when you're doing a targeted search of known accounts. Although, yes, it is also more efficient to select just the properties you need to return.
The below examples are based on a domain in the range of 20,000 account objects.
measure-command {Get-ADUser -Filter '*' -Properties DisplayName,st }
...
Seconds : 16
Milliseconds : 208
measure-command {$userlist | get-aduser -Properties DisplayName,st}
...
Seconds : 3
Milliseconds : 496
In the second example, $userlist contains 368 account names (just strings, not pre-fetched account objects).
Note that if I include the where clause per your suggestion to prune to the actually desired results, it's even more expensive.
measure-command {Get-ADUser -Filter '*' -Properties DisplayName,st |where {$userlist -Contains $_.samaccountname } }
...
Seconds : 17
Milliseconds : 876
Indexed attributes seem to have similar performance (I tried just returning displayName).
Even if I return all user account properties in my set, it's more efficient. (Adding a select statement to the below brings it down by a half-second).
measure-command {$userlist | get-aduser -Properties *}
...
Seconds : 12
Milliseconds : 75
I can't find a good document that was written in ye olde days about AD queries to link to, but you're hitting every account in your search scope to return the properties. This discusses the basics of doing effective AD queries - scoping and filtering: https://msdn.microsoft.com/en-us/library/ms808539.aspx#efficientadapps_topic01
When your search scope is "*", you're still building a (big) list of the objects and iterating through each one. An LDAP search filter is always more efficient to build the list first (or a narrow search base, which is again building a smaller list to query).