Windows PowerShell Quick Reference

Managing Errors

PowerShell supports two classes of errors: nonterminating errors and terminating errors. It collects both types of errors in the list represented by the $error automatic variable.

Nonterminating Errors

Most errors are nonterminating errors, in that they do not halt execution of the current cmdlet, script, function, or pipeline. When a command outputs an error (via PowerShell’s error-output facilities,) PowerShell writes that error to a stream called the error output stream.

You can output a nonterminating error using the Write-Error cmdlet (or the WriteError() API when writing a cmdlet).

The $ErrorActionPreference automatic variable allows you to control how PowerShell handles nonterminating errors. It supports the following values:

ErrorActionPreference automatic variable values
Value	Meaning
SilentlyContinue	Do not display errors.
Stop	Treat nonterminating errors as terminating errors.
Continue	Display errors, but continue execution of the current cmdlet, script, function, or pipeline. This is the default.
Inquire	Display a prompt that asks how PowerShell should treat this error.

Most cmdlets allow you to configure this explicitly by passing one of the above values to its ErrorAction parameter.

Terminating Errors

A terminating error halts execution of the current cmdlet, script, function, or pipeline. If a command (such as a cmdlet or .NET method call) generates a structured exception (for example, if you provide a method with parameters outside of their valid range), PowerShell ...