Regex Match for first line of Powershell Error Output - regex

Question

I am using new-pssession to connect to machines and am storing any errors in a value specified by the -errorVariable paramater. I want to call this variable later for output but on want to show the the first line, minus the comp name in brackets.
Heres an example of what i get.
New-PSSession : [ABCGFAXYZUT579] Connecting to remote server ABCGFAXYZUT579 failed with the
following error message : WinRM cannot complete the operation. Verify that the
specified computer name is valid, that the computer is accessible over the network, and that a
firewall exception for the WinRM service is enabled and allows access from this
computer. By default, the WinRM firewall exception for public profiles limits access to remote
computers within the same local subnet. For more information, see the
about_Remote_Troubleshooting Help topic.
At line:1 char:1
+ New-PSSession -ComputerName ABCGFAXYZUT579 -ErrorVariable errors912 ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : OpenError: (System.Manageme....RemoteRunspace:RemoteRunspace) [New-
PSSession], PSRemotingTransportException
+ FullyQualifiedErrorId : WinRMOperationTimeout,PSSessionOpenFailed
I have tried passing the variable to select-string to get only what i need but everything i have tried still gives me this
[ABCGFAXYZUT579] Connecting to remote server ABCGFAXYZUT579 failed with the following error
message : WinRM cannot complete the operation. Verify that the specified computer name
is valid, that the computer is accessible over the network, and that a firewall exception for
the WinRM service is enabled and allows access from this computer. By default, the
WinRM firewall exception for public profiles limits access to remote computers within the same
local subnet. For more information, see the about_Remote_Troubleshooting Help topic.
I have also tried splitting it into seperate lines like this
($errors912 -split '\r?\n' -ne '') and piping to select-string but i still get the above returned.
is there an easy way to get everything after the first white space and before the first period? leaving this?
Connecting to remote server ABCGFAXYZUT579 failed with the following error
message : WinRM cannot complete the operation.

Answer 1

$NewSession = New-PSSession -ComputerName ABCGFAXYZUT579 -ErrorVariable errors912 -ErrorAction SilentlyContinue
if ( $errors912.Count -gt 0 ) {
[string]$errors912 -replace "^(\[.*?\] )|(?<=\.).*"
}
Connecting to remote server ABCGFAXYZUT579 failed with the following error message : The WinRM client cannot process the request.
The $errors912.Count -gt 0 condition is equivalent to $null -eq $NewSession.
Please go to some on-line regex tester/debugger e.g. https://regex101.com/ for the regex explanation.