Appendix - Answers to Review Questions

This appendix provides concise answers to the review questions found at the end of each chapter. Use it to validate your understanding and reinforce key concepts.

Chapter 1 - Getting started with PowerShell

1. Use the $PSVersionTable automatic variable.
2. Only when you need to bypass User Account Control (UAC) for tasks that require elevation on the local computer.
3. The default execution policy on Windows client systems is Restricted, which prevents running scripts.
4. Use Get-ExecutionPolicy to determine the current execution policy.
5. Use Set-ExecutionPolicy (for example, Set-ExecutionPolicy -ExecutionPolicy RemoteSigned).

Chapter 2 - The Help system

1. No. The DisplayName parameter of Get-Service is named, not positional.
2. Get-Process has six parameter sets.
3. Use Get-Command -Noun EventLog.
4. Use Get-Process -Name powershell.
5. Run Update-Help (elevated as an administrator in Windows PowerShell) to download and install the latest help content.

Chapter 3 - Discovering objects, properties, and methods

1. Get-Process produces a System.Diagnostics.Process object.
2. Pipe the command to Get-Member.
3. Check whether the object has a method that performs the action.
4. Use the command's PassThru parameter, if it has one.
5. Run the command once and store the results in a variable to avoid repeatedly generating large amounts of output while prototyping.

Chapter 4 - One-Liners and the pipeline

1. A PowerShell one-liner is a single continuous pipeline, regardless of how many physical lines it spans.
2. Natural line breaks can occur at characters such as the pipe (|), comma (,), opening brackets ([ ]), braces ({ }), and parentheses (( )).
3. You should filter left to improve performance and efficiency by reducing the amount of data passed through the pipeline.
4. A command can accept pipeline input by value (by type) or by property name.
5. Because most content in the PowerShell Gallery is community-contributed and may not be vetted, it should be reviewed and tested before use.

Chapter 5 - Formatting, aliases, providers, comparison

1. Because formatting cmdlets produce format objects, which break the pipeline and can't be used by most other commands.
2. Use Get-Alias -Name % to determine the actual cmdlet.
3. Because aliases reduce readability and portability, making scripts more difficult for others to understand.
4. Use Get-ChildItem -Path HKLM:\, HKCU:\ to list registry keys in both hives.
5. The -replace operator is case-insensitive by default, whereas the .Replace() method is case-sensitive.

Chapter 6 - Flow control

1. ForEach-Object processes items one at a time from the pipeline (streaming), while the foreach statement processes items from a collection that's already loaded into memory.
2. A while loop evaluates its condition before running, so it may not run at all if the condition is false, unlike do while and do until, which run at least once.
3. break exits the loop entirely, while continue skips the current iteration and proceeds to the next one.

Chapter 7 - Working with WMI

1. WMI cmdlets (for example, Get-WmiObject) are older and use DCOM, while CIM cmdlets (for example, Get-CimInstance) are newer and use WSMan by default.
2. WSMan (Windows Remote Management).
3. CIM sessions allow reuse of connections, support alternate credentials, improve performance, and simplify managing multiple remote connections.
4. Create a session option with New-CimSessionOption, for example, to use DCOM, and pass it to New-CimSession, then use that session with Get-CimInstance.
5. Use Remove-CimSession.

Chapter 8 - PowerShell remoting

1. Use Enable-PSRemoting.
2. Use Enter-PSSession.
3. It allows you to use a persistent session instead of specifying the computer name and credentials with each command.
4. Yes, you can use a PowerShell session (PSSession) in a one-to-one interactive remoting scenario.
5. Locally run cmdlets return live objects with methods, while remote commands return deserialized objects without methods.

Chapter 9 - Functions

1. Use Get-Verb.
2. Add the [CmdletBinding()] attribute to the function.
3. When the function makes changes to system state or performs potentially impactful actions.
4. Specify -ErrorAction Stop.
5. To document how to use the function so you and others can easily understand it and access help with Get-Help.

Chapter 10 - Script modules

1. Create a .psm1 file and place your functions in it.
2. Using approved verbs ensures consistency, avoids warnings, and improves discoverability.
3. Use New-ModuleManifest.
4. Use Export-ModuleMember in the .psm1 file or specify functions in the FunctionsToExport field of the .psd1 file.
5. The module must be in a folder named the same as the module, located in a path listed in $env:PSModulePath, and contain the appropriate module file (.psm1 or manifest).

Final Notes

• These answers are intentionally concise to reinforce key concepts.
• Revisit the chapters for deeper understanding.