Logging actual error when script fails

Question

I have a script here that reads a list of computers and changes the administrator password. When the script is ran, it'll have a log file that says whether the task succeeded or fail. But I also want to log the actual error to the log when it fails. How do I accomplish this?

[cmdletbinding()]
param (
[parameter(mandatory = $true)]
$InputFile,
$OutputDirectory
)

if(!$outputdirectory) {
    $outputdirectory = (Get-Item $InputFile).directoryname
}   
$failedcomputers    =   Join-Path $outputdirectory "output.txt"
$stream = [System.IO.StreamWriter] $failedcomputers
$stream.writeline("ComputerName `t IsOnline `t PasswordChangeStatus")
$stream.writeline("____________ `t ________ `t ____________________")

$password = Read-Host "Enter the password" -AsSecureString
$confirmpassword = Read-Host "Confirm the password" -AsSecureString

$pwd1_text = [Runtime.InteropServices.Marshal]::PtrToStringAuto([Runtime.InteropServices.Marshal]::SecureStringToBSTR($password))
$pwd2_text = [Runtime.InteropServices.Marshal]::PtrToStringAuto([Runtime.InteropServices.Marshal]::SecureStringToBSTR($confirmpassword))

if($pwd1_text -ne $pwd2_text) {
    Write-Error "Entered passwords are not same. Script is exiting"
    exit
}

if(!(Test-Path $InputFile)) {
    Write-Error "File ($InputFile) not found. Script is exiting"
    exit
}

$Computers = Get-Content -Path $InputFile

foreach ($Computer in $Computers) {
    $Computer   =   $Computer.toupper()
    $Isonline   =   "OFFLINE"
    $Status     =   "SUCCESS"
    Write-Verbose "Working on $Computer"
    if((Test-Connection -ComputerName $Computer -count 1 -ErrorAction 0)) {
        $Isonline = "ONLINE"
        Write-Verbose "`t$Computer is Online"
    } else { Write-Verbose "`t$Computer is OFFLINE" }

    try {
        $account = [ADSI]("WinNT://$Computer/username,user")
        $account.psbase.invoke("setpassword",$pwd1_text)
        Write-Verbose "`tPassword Change completed successfully"
    }
    catch {
        $status = "FAILED"
        Write-Verbose "`tFailed to Change the administrator password. Error: $_"
    }

    $obj = New-Object -TypeName PSObject -Property @{
        ComputerName = $Computer
        IsOnline = $Isonline
        PasswordChangeStatus = $Status
    }

    $obj | Select ComputerName, IsOnline, PasswordChangeStatus

    if($Status -eq "FAILED" -or $Isonline -eq "OFFLINE") {
        $stream.writeline("$Computer `t $isonline `t $status")
    }

}
$stream.close()
Write-Host "`n`nFailed computers list is saved to $failedcomputers"

Answer 1

Change this:

catch {
    $status = "FAILED"
    Write-Verbose "`tFailed to Change the administrator password. Error: $_"
}

to this:

catch {
    $status = "FAILED"
    Write-Verbose "`tFailed to Change the administrator password. Error: $_"
    $errmsg = $_.Exception.Message
}

to preserve the error message(s). And change this:

if($Status -eq "FAILED" -or $Isonline -eq "OFFLINE") {
    $stream.writeline("$Computer `t $isonline `t $status")
}

to this:

if($Status -eq "FAILED" -or $Isonline -eq "OFFLINE") {
    $stream.writeline("$Computer `t $isonline `t $status `t $errmsg")
}

to include the error message in the log.

---

If you want to unroll inner exceptions as well you can use this:

$e = $_.Exception
$errmsg = $e.Message
while ($e.InnerException) {
  $e = $e.InnerException
  $errmsg = "`n" + $e.Message
}

instead of just

$errmsg = $_.Exception.Message