In all programming, the code will have errors, and troubleshooting those problems will be difficult. Like another programming language, PowerShell has error handling mechanisms for handling the error in our programming (in this post, we will discuss about Error handling with $ERROR variable).
In PowerShell, errors can be categories in 2 ways one is terminating and non-terminating. As the name implies, a terminating error stops the code execution when the error is thrown. A non-terminating error implies that the code will continue the next line of code execution when an error is shown.
The $Error Variable
$Error is an automatic global variable in PowerShell which always contains an Array List of zero or more Error Record objects. As new errors occur, they are added to the beginning of this list, so you can always get information about the most recent error by getting at $Error[0]. Both Terminating and Non-Terminating errors will be part of this this list.
How does the $Error variable work?
Starting a new PowerShell session the $Error will be empty. Normally, if you run a Windows PowerShell command and an error occurs, the error record will be appended to the “automatic variable” named $Error. Then we use the $Error[0] to display and access the rest of the information it holds.
The $Error variable hold a collection of information, and that’s why using $Error[0] can get to your error message objects. Also the $Error[0] variable will hold the last error message encountered until the PowerShell session ends.
Example #1: Starting a new PowerShell session
For this example, we have tried with a new PowerShell window session so the $Error variable has empty as shown below
$error[0]
Example #2: Executing the below script which had the error
When an error occurs in our code, it is saved to the Automatic variable named $Error. The $Error variable contains an array of recent errors, and you can reference the most recent error in the array at index 0.
In the below example, the path is not exit and instead of throwing an error we had included -ErrorAction SilentlyContinue, and next line we have written the current error using the $Error variable.
Get-content -Path “C:\dotnet-helpers\BLOG\TestFile.txt” -ErrorAction SilentlyContinue
Write-Warning $Error[0]
Getting Members of $Error Variable
We can use Get-Member to expose your PS variable objects. using the below-listed members we can get deeper into the $Error[0] object to extract
Example #3: Getting the detailed Error using $Error variable
In the below example, we can get deeper into the $Error[0] object to extract the line that failed during execution.This assumes that the error information is available in the first element of the $Error array. The InvocationInfo property of the ErrorRecord object contains information about the context in which the error occurred, including the line number.
Keep in mind that if there are multiple errors in the $Error array, you might want to loop through them or access a specific error by its index. Also, note that this information might not be available for all types of errors, depending on how the error was generated
$Error[0].InvocationInfo
#Display the failed code line
Write-Host “Error occured at line : ” $Error[0].InvocationInfo.line
