ErrorAction parameter in PowerShell - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of the ErrorAction parameter in PowerShell?

The ErrorAction parameter controls how PowerShell responds to non-terminating errors during command execution. It lets you decide whether to continue, stop, silently ignore, or ask for user input when an error occurs.

beginner

Name the common values you can assign to the ErrorAction parameter.

Common values include:
- Continue: Show error and continue (default)
- Stop: Stop execution on error
- SilentlyContinue: Ignore error without message
- Inquire: Ask user what to do
- Ignore: Ignore error and don't add to error stream

beginner

How do you use ErrorAction to stop a script when a command fails?

Add -ErrorAction Stop to the command. This makes PowerShell treat non-terminating errors as terminating, so the script stops immediately on error.

beginner

What happens if you set ErrorAction to SilentlyContinue?

PowerShell ignores the error and does not display any message. The script continues running as if no error happened.

beginner

Give an example of a PowerShell command using ErrorAction to silently ignore errors.

Example:
Get-Item 'C:\nonexistentfile.txt' -ErrorAction SilentlyContinue
This command tries to get a file that doesn't exist but won't show an error message.

What does -ErrorAction Stop do in a PowerShell command?

A Asks the user what to do

B Ignores the error silently

C Continues and shows the error message

D Stops the script if an error occurs

-ErrorAction Stop makes PowerShell treat errors as terminating, stopping the script immediately.

Which ErrorAction value will NOT display any error message but continue running?

A SilentlyContinue

B Stop

C Continue

D Inquire

SilentlyContinue ignores errors without showing messages.

If you want PowerShell to ask you what to do when an error happens, which ErrorAction value should you use?

A Ignore

B Inquire

C Stop

D Continue

Inquire prompts the user to decide how to handle the error.

What is the default behavior of PowerShell when an error occurs and ErrorAction is not specified?

A Stop execution

B Silently ignore error

C Continue and show error message

D Ask user for input

By default, PowerShell continues running and shows the error message (Continue).

Which ErrorAction value completely ignores the error and does not add it to the error stream?

A Ignore

B SilentlyContinue

C Stop

D Continue

Ignore suppresses the error and does not add it to the error stream, unlike SilentlyContinue.

Explain how the ErrorAction parameter changes the way PowerShell handles errors in a script.

Think about how you want your script to behave when something goes wrong.

Describe a situation where using -ErrorAction SilentlyContinue would be helpful.

Imagine you check for a file that might not exist, but it’s okay if it doesn’t.

Practice

1. What does the -ErrorAction SilentlyContinue parameter do in a PowerShell command?

easy

A. It displays error messages and pauses the script.

B. It stops the script immediately when an error occurs.

C. It suppresses error messages and continues running the script.

D. It logs errors to a file but shows no messages.

Solution

1. Step 1: Understand the SilentlyContinue behavior

   The SilentlyContinue value tells PowerShell to hide error messages and keep running the script without interruption.

2. Step 2: Compare with other ErrorAction values

   Unlike Stop, which halts the script, SilentlyContinue ignores errors silently, so the script continues smoothly.

3. Final Answer:

   It suppresses error messages and continues running the script. -> Option C

4. Quick Check:

   SilentlyContinue = suppress errors and continue [OK]

Hint: SilentlyContinue hides errors and keeps script running [OK]

Common Mistakes:

• Confusing SilentlyContinue with Stop which halts execution
• Thinking errors are logged automatically
• Assuming errors still display on screen

2. Which of the following is the correct syntax to stop a PowerShell script on error using the ErrorAction parameter?

easy

A. Get-Item 'C:\file.txt' -ErrorAction Stop

B. Get-Item 'C:\file.txt' -ErrorAction Ignore

C. Get-Item 'C:\file.txt' -ErrorAction SilentlyContinue

D. Get-Item 'C:\file.txt' -ErrorAction Continue

Solution

1. Step 1: Identify the ErrorAction value that stops script

   The Stop value causes the script to halt immediately when an error occurs.

2. Step 2: Verify syntax correctness

   The syntax uses -ErrorAction Stop correctly after the command.

3. Final Answer:

   Get-Item 'C:\file.txt' -ErrorAction Stop -> Option A

4. Quick Check:

   ErrorAction Stop halts script on error [OK]

Hint: Use -ErrorAction Stop to halt script on errors [OK]

Common Mistakes:

• Using Continue which only shows errors but continues
• Using SilentlyContinue which hides errors but continues
• Using non-existent value Ignore

3. What will be the output of this PowerShell command?

Get-Item 'C:\nonexistentfile.txt' -ErrorAction SilentlyContinue; Write-Output 'Done'

medium

A. Only 'Done' is printed, no error message

B. Error message about missing file, then 'Done'

C. Script stops with error, no output

D. Nothing is printed

Solution

1. Step 1: Analyze Get-Item with SilentlyContinue

   The command tries to get a missing file but errors are suppressed silently.

2. Step 2: Check what Write-Output does after

   Since error is suppressed, the script continues and prints 'Done'.

3. Final Answer:

   Only 'Done' is printed, no error message -> Option A

4. Quick Check:

   SilentlyContinue hides errors, script continues [OK]

Hint: SilentlyContinue hides errors, next commands run [OK]

Common Mistakes:

• Expecting error message to show
• Thinking script stops on error
• Assuming no output at all

4. You wrote this script:

Get-Content 'C:\missing.txt' -ErrorAction Stop
Write-Output 'File read successfully'

But the script does not print 'File read successfully' when the file is missing. What is the fix?

medium

A. Change -ErrorAction Stop to -ErrorAction SilentlyContinue

B. Add try/catch block around Get-Content

C. Remove the Write-Output line

D. Change -ErrorAction Stop to -ErrorAction Continue

Solution

1. Step 1: Understand Stop behavior

   -ErrorAction Stop halts script on error, so Write-Output is not reached if file missing.

2. Step 2: Use try/catch to handle error gracefully

   Wrapping Get-Content in try/catch lets you catch the error and continue script safely.

3. Final Answer:

   Add try/catch block around Get-Content -> Option B

4. Quick Check:

   Stop halts script; try/catch handles errors [OK]

Hint: Use try/catch with Stop to handle errors safely [OK]

Common Mistakes:

• Changing Stop to SilentlyContinue hides errors but may ignore important failures
• Removing Write-Output loses useful output
• Using Continue still shows errors but doesn't stop script

5. You want to run a script that tries to delete multiple files. If a file is missing, you want to skip it silently and continue deleting others. But if a file exists but cannot be deleted due to permission issues, the script should stop immediately. Which ErrorAction usage fits this requirement?

hard

A. Use Remove-Item -ErrorAction Continue and handle errors in catch block

B. Use Remove-Item -ErrorAction Stop for all files

C. Use Remove-Item -ErrorAction SilentlyContinue for all files

D. Use Remove-Item -ErrorAction SilentlyContinue and check error type manually

Solution

1. Step 1: Understand SilentlyContinue hides all errors

   Using SilentlyContinue alone skips errors silently, so permission errors won't stop script.

2. Step 2: Combine SilentlyContinue with manual error check

   Run Remove-Item with SilentlyContinue, then check error details to stop on permission errors but ignore missing files.

3. Final Answer:

   Use Remove-Item -ErrorAction SilentlyContinue and check error type manually -> Option D

4. Quick Check:

   SilentlyContinue + manual check = skip missing, stop permission errors [OK]

Hint: SilentlyContinue plus manual error check handles complex cases [OK]

Common Mistakes:

• Using Stop stops on all errors including missing files
• Using Continue shows errors but does not stop script
• Ignoring error type and blindly continuing