Whitespace & $null variable handling in PowerShell? - powershell

Question

I'm trying to create a script that will grab all users in an OU and change the current primary alias to a secondary alias while adding a new primary smtp address and retaining any other secondary aliases. We have users with 0 aliases, some with 1, some with 2, and some with 3. I am running into an issue when any one of the $sp1, $sp2, $sp3, $sp4, $sp5 are either white space or null. I'm still learning powershell so I'm not sure how to handle that without a lot of pain lol.
$Users = Get-AdUser -Filter * -SearchBase "OU=TestScriptedSMTPAddrChange,OU=***,DC=***,DC=com" -Properties proxyAddresses | Select-Object SamAccountName, proxyAddresses #Change first OU= to the OU you want to change
Foreach ($SAN in $Users){
$SecondaryProxyRaw = $SAN.proxyAddresses #grab proxyAddresses and dump them
$SecondaryProxyRed = $SecondaryProxyRaw.replace('SMTP','smtp') #change primary SMTP addr to secondary smtp addr
$sp1,$sp2,$sp3,$sp4,$sp5 = $SecondaryProxyRed.split(" ",1) #split the proxyAddresses array into variables
$NewPrimaryProxy = "SMTP:$($SAN.SamAccountName)#newdomain.com"} #assign new primary SMTP address
Set-ADUser -Identity $SAN.SamAccountName -replace #{proxyAddresses = "$NewPrimaryProxy","$sp1","$sp2","$sp3","$sp4","$sp5"}
}
Get-AdUser -Filter * -SearchBase "OU=TestScriptedSMTPAddrChange,OU=***,DC=***,DC=com" -Properties proxyAddresses | Select-Object SamAccountName, UserPrincipalName, #{Name="Proxyaddresses";Expression={$_.proxyAddresses -join "*"}}

Answer 1

You should not rely on a user having 1, 3 or perhaps 77 addresses in its proxyAddresses attribute by trying to split these into a fixed number of variables.
Just get them all, replace the uppercase SMTP: into lowercase 'smtp:', filter out the possible one that would be equal to the new proxy address and add the new primary address to the array.
Then, replace the entire proxyAddresses array with the strongly typed (i.e. cast to string[]]) new array.
$Users = Get-AdUser -Filter * -SearchBase "OU=TestScriptedSMTPAddrChange,OU=***,DC=***,DC=com" -Properties proxyAddresses
foreach ($SAN in $Users) {
$NewPrimaryProxy = 'SMTP:{0}#newdomain.com' -f $SAN.SamAccountName
# if you like you can sort the proxies but for the system this will have no effect
$proxies = #($SAN.ProxyAddresses -replace '^SMTP:', 'smtp:' | Where-Object { $_ -ne $NewPrimaryProxy }) + $NewPrimaryProxy
# Note: proxyAddresses needs a Strongly typed string array, that is why we cast $proxies array with [string[]]
$SAN | Set-ADUser -Replace #{proxyAddresses = [string[]]$proxies}
}

Answer 2

.split(" ",1)
doesn't split at all - by definition it returns the input string as-is, because you're asking for 1 token only - see the docs for the .NET [string] type's .Split() method.
To split by runs of whitespace, you can use the unary form of PowerShell's -split operator:
# Split by whitespace and collect tokens in an array.
# -ne '' filters out empty elements, so that if
# $SecondaryProxyRed is effectively empty, $sps becomes an empty array.
$sps = -split $SecondaryProxyRed -ne ''
You can then create an array with $NewPrimaryProxy as the first element, followed by the elements of $sps, if any:
Set-ADUser -Identity $SAN.SamAccountName -replace #{
proxyAddresses = #($NewPrimaryProxy) + $sps
}