Stop a script when an error occurs in PowerShell

By default, PowerShell writes errors to the error stream and continues executing the script rather than stopping. You can change this behavior by setting the $ErrorActionPreference variable to Stop, which causes PowerShell to halt the script whenever an error occurs.

PowerShell has two kinds of commands: cmdlets and native commands. For example, Get-ChildItem is a cmdlet, and git is a native command. The $ErrorActionPreference variable has controlled cmdlet behavior since the first version of PowerShell. In PowerShell 7.3, the $PSNativeCommandUseErrorActionPreference variable was introduced to provide the same control for native commands.

Setting $ErrorActionPreference to Stop halts the script when a cmdlet throws an error. Setting $PSNativeCommandUseErrorActionPreference to true extends this behavior to native commands. A good practice is to set both variables at the beginning of your scripts:

# Stop the script when a cmdlet or a native command fails
$ErrorActionPreference = 'Stop'
$PSNativeCommandUseErrorActionPreference = $true

You can override $ErrorActionPreference for a specific cmdlet using the -ErrorAction parameter. For instance, the following command continues even if Get-ChildItem fails:

Get-ChildItem dummy -ErrorAction SilentlyContinue

To bypass $PSNativeCommandUseErrorActionPreference for a specific native command, use the & { } syntax to run the command inside a script block. Set $PSNativeCommandUseErrorActionPreference to false within the block; the variable reverts to its previous value when the block exits.

& {
    # Disable $PSNativeCommandUseErrorActionPreference for this scriptblock only
    $PSNativeCommandUseErrorActionPreference = $false
    robocopy.exe dummy1 dummy2
    if ($LASTEXITCODE -gt 8) {
        throw "robocopy failed with exit code $LASTEXITCODE"
    }
}

#Additional resources

• about_Preference_Variables

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