Hot on the heels of our last Great Debate, let’s take the discussion to the next logical step and talk about how you like to capture errors when they occur.
The first technique is to use -ErrorVariable:

`Try { Get-WmiObject Win32_BIOS -comp nothing -ea stop -ev mine } Catch {

use $mine for error

} `Another is to use the $Error collection:

`Try { Get-WmiObject Win32_BIOS -comp badname -ea stop } Catch {

use $error[0]

} `And a third is to use $_:

`Try { Get-WmiObject Win32_BIOS -comp snoopy -ea stop } Catch {

use $_

} `Personally, I’ve always disliked the last approach, because people don’t realize that in some situations $_ can get “hijacked.” For example:

Get-Content names.txt | ForEach-Object { Try { Get-WmiObject Win32_BIOS -Comp $_ -EA Stop } Catch { # is $_ an error or a computer name? } } Now, I’m a big not-fan of using pipelines like this in a script, but that’s another debate (it’s on my list). The point is really that I can’t universally, 100% rely on $… and when someone uses $ without realizing what’s happening, they back themselves into a tricky corner that’s difficult to diagnose. Since my big focus is on learning and teaching, I tend to want to teach techniques that are universal and always work the same way.
That said, $error[0] and the -ErrorVariable (-EV) technique return slightly different objects, meaning you have to work with them somewhat differently.
So what’s your preference? Why? Which of these don’t you like so much… and why?
[boilerplate greatdebate]