HELP ABOUT_TRAP produces nothing. Scanning output of HELP for TRAP and
EXCEPTION produces nothing.

How do I handle exceptions in Windows PowerShell?



Thanks.

In PowerShell you use the trap statement to handle errors. There's a
little info about traps in the about_break help file as well as in the
Tri-fold reference that's installed with PowerShell (just the basic
structure of the trap statement really).

A better source is the PowerShell team blog. There's a four or five
part series about error handling in (at the time Monad, but it all
still holds true) PowerShell. You can find the first blog in the series
here: http://blogs.msdn.com/monad/archive/...04/489138.aspx

Tom G.
--



John Smith wrote:

> HELP ABOUT_TRAP produces nothing. Scanning output of HELP for TRAP
> and EXCEPTION produces nothing.
>
> How do I handle exceptions in Windows PowerShell?
>
> Thanks.

Thanks. But can't find part 9 which talks about trapping errors.

"Tom G." wrote:

> A better source is the PowerShell team blog. There's a four or five
> part series about error handling in (at the time Monad, but it all
> still holds true) PowerShell. You can find the first blog in the series
> here: http://blogs.msdn.com/monad/archive/...04/489138.aspx
>
> Tom G.
> --

Found the article. But it's by examples. What goes into the [ ]? I tried[*] and it didn't work. I tried [] and it didn't work either.

In a function, it appears that RETURN or BREAK in a TRAP block does not exit
the function:

PS C:\> function validate-imagefile([String]$file)
>> {
>> trap [System.SystemException] {
>> write-host "Error is " $_ -foreground green
>> return (1 -eq 2); }
>> $img = New-Object -typename System.Drawing.Bitmap -ArgumentList $file
>> Remove-variable img
>> return (1 -eq 1)
>> }
>> validate-imagefile("xxx")
>>
Error is Exception calling ".ctor" with "1" argument(s): "Parameter is not
valid."
New-Object : Exception calling ".ctor" with "1" argument(s): "Parameter is
not valid."
At line:6 char:20
+ $img = New-Object <<<< -typename System.Drawing.Bitmap -ArgumentList
$file
Remove-Variable : Cannot find a variable with name 'img'.
At line:7 char:18
+ Remove-variable <<<< img
False
True