Pipeline object flow in PowerShell - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to send the output of Get-Process to the pipeline.

PowerShell

Get-Process | [1]

Drag options to blanks, or click blank then click option'

ANew-Item

BSort-Object

CGet-Item

DWrite-Host

Attempts:

3 left

💡 Hint

Common Mistakes

Using Write-Host breaks the pipeline by converting objects to text.

Get-Item and New-Item do not accept pipeline input from Get-Process.

The pipeline sends objects from Get-Process to Sort-Object to sort the processes.

2fill in blank

medium

Complete the code to filter processes with CPU usage greater than 100.

PowerShell

Get-Process | Where-Object { $_.CPU [1] 100 }

Drag options to blanks, or click blank then click option'

A<

B-ne

C-eq

D>

Attempts:

3 left

💡 Hint

Common Mistakes

Using '<' filters processes with CPU less than 100, which is opposite.

Using '-eq' or '-ne' checks for equality or inequality, not greater than.

The '>' operator filters processes where CPU usage is greater than 100.

3fill in blank

hard

Fix the error in the pipeline to select the process names only.

PowerShell

Get-Process | Select-Object -Property [1]

Drag options to blanks, or click blank then click option'

AName

BPath

CId

DCPU

Attempts:

3 left

💡 Hint

Common Mistakes

Selecting 'Id' or 'CPU' returns other properties, not the names.

Selecting 'Path' may return null for some processes.

Selecting the 'Name' property returns the process names as objects in the pipeline.

4fill in blank

hard

Fill both blanks to create a pipeline that gets services and filters only running ones.

PowerShell

Get-Service | Where-Object { $_.[1] -eq '[2]' }

Drag options to blanks, or click blank then click option'

AStatus

BName

CStopped

DRunning

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'Name' instead of 'Status' as the property.

Filtering for 'Stopped' instead of 'Running'.

Filtering services where Status equals 'Running' shows only running services.

5fill in blank

hard

Fill all three blanks to create a pipeline that gets processes, selects their names and CPU, and filters those with CPU over 50.

PowerShell

Get-Process | Select-Object [1], [2] | Where-Object { $_.[3] -gt 50 }

Drag options to blanks, or click blank then click option'

AName

BCPU

DId

Attempts:

3 left

💡 Hint

Common Mistakes

Selecting 'Id' instead of 'CPU' for filtering.

Filtering on a property not selected in Select-Object.

Select 'Name' and 'CPU' properties, then filter where CPU is greater than 50.

Practice

1. What does the pipeline operator | do in PowerShell?

easy

A. It sends the output of one command as input to the next command.

B. It comments out the rest of the line.

C. It creates a new variable.

D. It ends the script execution.

Solution

1. Step 1: Understand the pipeline operator

   The pipeline operator | connects commands by passing output from one as input to the next.

2. Step 2: Identify its role in command chaining

   This allows commands to work together smoothly without temporary files or variables.

3. Final Answer:

   It sends the output of one command as input to the next command. -> Option A

4. Quick Check:

   Pipeline operator = passes output to next command [OK]

Hint: Pipeline | passes output to next command [OK]

Common Mistakes:

• Thinking | is a comment symbol
• Confusing | with variable assignment
• Assuming | stops script execution

2. Which of the following is the correct syntax to filter files larger than 1MB using the pipeline?

easy

A. Get-ChildItem | Where-Object { $_.Length -gt 1MB }

B. Get-ChildItem | Where-Object { $_.Length > "1MB" }

C. Get-ChildItem | Where-Object { Length -gt 1MB }

D. Get-ChildItem | Where-Object Length -gt "1MB"

Solution

1. Step 1: Check the correct property and operator usage

   In PowerShell, filter with Get-ChildItem | Where-Object { $_.Length -gt 1MB }. 1MB is a valid byte literal (1048576 bytes). Use $_. for current object and -gt for greater than.

2. Step 2: Why others are incorrect

   B uses > "1MB" (string comparison, incorrect filtering). C omits $_. (undefined Length). D simplified syntax with "1MB" (string compare).

3. Final Answer:

   Get-ChildItem | Where-Object { $_.Length -gt 1MB } -> Option A

4. Quick Check:

   $_.Length -gt 1MB (numeric) [OK]

Hint: Use $_.Property inside braces for filtering [OK]

Common Mistakes:

• Omitting $_. before property name
• Quoting size (\"1MB\") causing string comparison
• Misplacing parameters outside script block

3. What is the output of this command?

Get-Process | Where-Object { $_.CPU -gt 100 } | Select-Object -Property Name

medium

A. Empty list because no process uses CPU

B. List of all processes with CPU property

C. Error because CPU is not a valid property

D. List of process names using more than 100 CPU seconds

Solution

1. Step 1: Filter processes by CPU usage

   The command filters processes where the CPU time is greater than 100 seconds.

2. Step 2: Select only the Name property

   After filtering, it selects and outputs only the process names.

3. Final Answer:

   List of process names using more than 100 CPU seconds -> Option D

4. Quick Check:

   Filtering then selecting property = filtered names [OK]

Hint: Filter first, then select properties to see desired output [OK]

Common Mistakes:

• Assuming CPU is not a valid property
• Expecting full process details instead of just names
• Thinking the output is empty without checking actual CPU usage

4. Identify the error in this pipeline:

Get-Service | Where-Object { $_.Status = 'Running' }

medium

A. Where-Object cannot be used with Get-Service

B. Missing pipeline operator (|) between commands

C. Using single equals (=) instead of comparison operator (-eq)

D. Incorrect property name 'Status'

Solution

1. Step 1: Check the comparison operator in Where-Object

   The script uses = which is an assignment, not a comparison. PowerShell requires -eq for equality checks.

2. Step 2: Confirm pipeline and property usage

   The pipeline operator is present and Status is a valid property of service objects.

3. Final Answer:

   Using single equals (=) instead of comparison operator (-eq) -> Option C

4. Quick Check:

   Use -eq for comparisons, not = [OK]

Hint: Use -eq for equality, not = inside script blocks [OK]

Common Mistakes:

• Confusing = with -eq in conditions
• Removing pipeline operator accidentally
• Assuming property names are incorrect without checking

5. You want to list all files in a folder and its subfolders, sorted by size descending, but only show the top 5 largest files. Which pipeline command achieves this?

hard

A. Get-ChildItem | Sort-Object Length -Descending | Select-Object -First 5

B. Get-ChildItem -Recurse | Sort-Object Length -Descending | Select-Object -First 5

C. Get-ChildItem -Recurse | Where-Object Length -gt 5 | Sort-Object Length

D. Get-ChildItem -Recurse | Select-Object -First 5 | Sort-Object Length -Descending

Solution

1. Step 1: Include all files recursively

   Use -Recurse with Get-ChildItem to get files in all subfolders.

2. Step 2: Sort files by size descending and select top 5

   Sort by Length descending, then select the first 5 files.

3. Final Answer:

   Get-ChildItem -Recurse | Sort-Object Length -Descending | Select-Object -First 5 -> Option B

4. Quick Check:

   Recurse + sort descending + select first 5 = correct pipeline [OK]

Hint: Recurse first, then sort descending, then select top items [OK]

Common Mistakes:

• Forgetting -Recurse to include subfolders
• Selecting top 5 before sorting
• Using Where-Object incorrectly to filter by number