In PowerShell, the $ErrorActionPreference variable controls how PowerShell responds to non-terminating errors. It determines the default behaviour when an error occurs within a script or command. Understanding the different options of $ErrorActionPreference is crucial for effective error handling.
Here are the different options and what each does:
- Continue: This is the default value. When an error occurs, PowerShell displays the error message but continues executing the remaining commands in the script. It does not halt the script execution.
- SilentlyContinue: PowerShell suppresses the error message and continues executing the script as if no error occurred. It does not display any error messages to the user. This option is useful when you want to handle errors programmatically without interrupting the script flow.
- Stop: When an error occurs, PowerShell displays the error message and stops executing the script. It terminates the script execution immediately after encountering the error. This behaviour is useful when you want to ensure that any error is addressed before proceeding further.
- Inquire: PowerShell prompts the user to choose whether to continue executing the script or not when an error occurs. This option allows for interactive error handling, where the user can decide how to proceed based on the error message.
- Ignore: PowerShell ignores the error completely and continues executing the script without displaying the error message. It treats the error as if it didn’t occur. This option is not recommended for most scenarios as it can lead to unexpected behaviour and potential data loss.
To modify the $ErrorActionPreference variable, you can assign one of the above values to it. For example:
$ErrorActionPreference = "Stop"
This sets the error action preference to “Stop”, meaning PowerShell will halt script execution upon encountering an error.
You can also scope the $ErrorActionPreference variable to specific parts of your script using the Scope parameter:
$ErrorActionPreference = "Stop" -Scope Script
This sets the error action preference to “Stop” only within the current script scope.
By understanding and appropriately setting the $ErrorActionPreference, you can control how PowerShell handles errors within your scripts, ensuring they behave as expected and provide a better user experience.
Recommended Reading: Understanding Try/Catch Error Handling in PowerShell