I seem unable to catch an exception thrown by Start-Service
. Here is my code:
try
{
start-service "SomeUnStartableService"
}
catch [Microsoft.PowerShell.Commands.ServiceCommandException]
{
write-host "got here"
}
When I run this, the exception is thrown but not caught:
*Service 'SomeUnStartableService' start failed.
At开发者_如何学编程 line:3 char:18
+ start-service <<<< "SomeUnStartableService"
+ CategoryInfo : OpenError: (System.ServiceProcess.ServiceController:ServiceController) [Start-Service], ServiceCommandException
+ FullyQualifiedErrorId : StartServiceFailed,Microsoft.PowerShell.Commands.StartServiceCommand*
$ErrorActionPreference
is set to Stop, so this shouldn't be the problem.
When I alter my code to catch [Exception]
, the exception is caught and "got here" is printed.
Does start-service
throw a ServiceCommandException
or something else? It looks as though it is but I cannot catch it!
--- Edit ---
Ideally I could write the following, and throw an exception if start-service
did not throw an exception, and only catch an exception thrown by start-service
:
try
{
start-service "SomeUnStartableService"
throw (new-object Exception("service started when expected not to start"))
}
catch [Microsoft.PowerShell.Commands.ServiceCommandException]
{
write-host "got here"
}
Try/Catch works only on terminating errors. Use the ErrorAction parameter with a value of Stop to make the error a terminating error and then you'll be able to catch it:
try
{
start-service "SomeUnStartableService" -ErrorAction Stop
}
catch
{
write-host "got here"
}
UPDATE:
When you set $ErrorActionPreference to 'stop' (or use -ErrorAction Stop) the error type you get is ActionPreferenceStopException, so you can use it to catch the error.
$ErrorActionPreference='stop'
try
{
start-service SomeUnStartableService
}
catch [System.Management.Automation.ActionPreferenceStopException]
{
write-host "got here"
}
}
I usually don't limit the catch-phrase but handle the exceptions with logical tests within the catch-block:
try
{
start-service "SomeUnStartableService" -ea Stop
}
catch
{
if ( $error[0].Exception -match "Microsoft.PowerShell.Commands.ServiceCommandException")
{
#do this
}
else
{
#do that
}
}
Maybe not as clean, and may result in huge catch blocks. But if it works... ;)
To discover your exception you can use :
try
{
start-service "SomeUnStartableService" -ea Stop
}
catch
{
$_.exception.gettype().fullname
}
Edited : Here is a kind of bypass with SystemException
try
{
start-service "SomeUnStartableService" -ea Stop
}
catch [SystemException]
{
write-host "got here"
}
"Microsoft.PowerShell.Commands.ServiceCommandException" will also be true when not run elevated. Just saying.
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