Check if a command has run successfully

Question

I\'ve tried enclosing the following in an if statement so I can execute another command if this succeeds:

Get-WmiObject -Class Win32_Share -ComputerName $Ser         


        

Answer 1

Or if a failure returns no standard output, that would work for an if statement:

if (! (Get-CimInstance Win32_Share -ComputerName $Server.name -Credential $credentials -Filter "Description='Default share'")) { 
  'command failed'
}

Also there's now the or symbol "||" in powershell 7:

Get-CimInstance Win32_Share -ComputerName $Server.name -Credential $credentials -Filter "Description='Default share'" || 'command failed'

Answer 2

Try the $? automatic variable:

$share = Get-WmiObject -Class Win32_Share -ComputerName $Server.name -Credential $credentials -Filter "Description='Default share'"

if($?)
{
   "command succeeded"
   $share | Foreach-Object {...}
}
else
{
   "command failed"
}

From about_Automatic_Variables:

$?
   Contains the execution status of the last operation. It contains
TRUE if the last operation succeeded and FALSE if it failed.
...

$LastExitCode
   Contains the exit code of the last Windows-based program that was run.

Answer 3

There are instances where any of the options are best suitable. Here is another method:

try {
Add-AzureADGroupMember -ObjectId XXXXXXXXXXXXXXXXXXX -RefObjectId (Get-AzureADUser -ObjectID "XXXXXXXXXXXXXX").ObjectId  -ErrorAction Stop
Write-Host "Added successfully" -ForegroundColor Green
$Count = $Null
$Count = 1
}
catch {
$Count = $Null
$Count = 0
Write-Host "Failed to add: $($error[0])"  -ForegroundColor Red
}

With try and catch, you don't only get the error message returned when it fails, you also have the $count variable assigned the number 0. When the command is successful, your $count value returns 1. At this point, you use this variable value to determine what happens next.

Answer 4

you can try :

$res = get-WmiObject -Class Win32_Share -Filter "Description='Default share'"
if ($res -ne $null)
{
  foreach ($drv in $res)
  {
    $Localdrives += $drv.Path
  }
}
else
{
  # your error
}