If I'm calling a cmdlet in a PSh script, what is the best way to trap for
errors in the cmdlet? In other words, I call the cmdlet then do a bunch of
things afterwards. I'd like to script to bail out if the cmdlet throws an
exception. I'm sure this is easy, but just looking for the "right" approach.

Thanks!

Darren

Place the trap before the call to the Cmdlet. '$_' holds the error information. Use exit in the trap to exit the script. If the error is a non-terminating error set the Cmdlet's -ErrorAction parameter to Stop or 1:

Try these sample scripts:

-< test1.ps1 >-
trap {
'Exception trapped!'
$_
exit
}
# non-terminating error, ignored by trap
Get-Content nosuchdir

# terminating error
Get-Date 'Monday'

"last line, should not be displayed"
-< end >-

# - - - - - - - - #

-< test2.ps1 >-
trap {
'Exception trapped!'
$_
exit
}
# set -ErrorAction to Stop
# on non-terminating error
Get-Content nosuchdir -ea 1

# terminating error
Get-Date 'Monday'

"last line, should not be displayed"
-< end >-

--
Kiron

If you are used to try-catch-finally functionality and would prefer to use
that in your scripts, you should read this blog post:

http://weblogs.asp.net/adweigert/arc...s-to-life.aspx

--
Kirk Munro
Poshoholic
http://poshoholic.com


"Kiron" <Kiron@xxxxxx> wrote in message
news:C686D8FD-E416-4DD7-BFEF-2C78AAF1789B@xxxxxx

> Place the trap before the call to the Cmdlet. '$_' holds the error
> information. Use exit in the trap to exit the script. If the error is a
> non-terminating error set the Cmdlet's -ErrorAction parameter to Stop or
> 1:
>
> Try these sample scripts:
>
> -< test1.ps1 >-
> trap {
> 'Exception trapped!'
> $_
> exit
> }
> # non-terminating error, ignored by trap
> Get-Content nosuchdir
>
> # terminating error
> Get-Date 'Monday'
>
> "last line, should not be displayed"
> -< end >-
>
> # - - - - - - - - #
>
> -< test2.ps1 >-
> trap {
> 'Exception trapped!'
> $_
> exit
> }
> # set -ErrorAction to Stop
> # on non-terminating error
> Get-Content nosuchdir -ea 1
>
> # terminating error
> Get-Date 'Monday'
>
> "last line, should not be displayed"
> -< end >-
>
> --
> Kiron

Thanks Kirk and Kiron. Very useful info.


Darren

"Kirk Munro" <sorry@xxxxxx> wrote in message
news:Osye$MsMIHA.292@xxxxxx

> If you are used to try-catch-finally functionality and would prefer to use
> that in your scripts, you should read this blog post:
>
> http://weblogs.asp.net/adweigert/arc...s-to-life.aspx
>
> --
> Kirk Munro
> Poshoholic
> http://poshoholic.com
>
>
> "Kiron" <Kiron@xxxxxx> wrote in message
> news:C686D8FD-E416-4DD7-BFEF-2C78AAF1789B@xxxxxx

>> Place the trap before the call to the Cmdlet. '$_' holds the error
>> information. Use exit in the trap to exit the script. If the error is a
>> non-terminating error set the Cmdlet's -ErrorAction parameter to Stop or
>> 1:
>>
>> Try these sample scripts:
>>
>> -< test1.ps1 >-
>> trap {
>> 'Exception trapped!'
>> $_
>> exit
>> }
>> # non-terminating error, ignored by trap
>> Get-Content nosuchdir
>>
>> # terminating error
>> Get-Date 'Monday'
>>
>> "last line, should not be displayed"
>> -< end >-
>>
>> # - - - - - - - - #
>>
>> -< test2.ps1 >-
>> trap {
>> 'Exception trapped!'
>> $_
>> exit
>> }
>> # set -ErrorAction to Stop
>> # on non-terminating error
>> Get-Content nosuchdir -ea 1
>>
>> # terminating error
>> Get-Date 'Monday'
>>
>> "last line, should not be displayed"
>> -< end >-
>>
>> --
>> Kiron

>
>

"Darren Mar-Elia" <dmanonymous@xxxxxx> wrote in message
news:2B668D38-8B7F-434F-B23A-2F0967D18CDB@xxxxxx

> If I'm calling a cmdlet in a PSh script, what is the best way to trap for
> errors in the cmdlet? In other words, I call the cmdlet then do a bunch of
> things afterwards. I'd like to script to bail out if the cmdlet throws an
> exception. I'm sure this is easy, but just looking for the "right"
> approach.
>

It sounds like to me that you don't need to trap errors. You just want to
enforce that if the cmdlet errors, the error is a terminating error instead
of a non-terminating error. To do this, use the ubiqitous
parameter -ErrorAction and set it to Stop e.g.:

Get-ChildItem someNameThatDoesntExist -ErrorAction Stop

This will cause script execution to jump to the previous trap handler in
scope and on up the call stack. If none exists the script will exit
automatically with that error.

Another option, if you want this behavior for all cmdlet calls within a
certain scope, is to set $ErrorActionPreference = 'Stop' before the cmdlet
invocations.

--
Keith