Select-String for searching in PowerShell - Practice Problems & Coding Challenges

Challenge - 5 Problems

💻 Command Output

intermediate

What is the output of this Select-String command?

Given a file named log.txt with the following content:

Info: Start process
Error: File not found
Warning: Low memory
Error: Access denied

What will be the output of this command?

Select-String -Path log.txt -Pattern 'Error'

PowerShell

Select-String -Path log.txt -Pattern 'Error'

A

Info: Start process
Warning: Low memory

B

Error: File not found
Error: Access denied

C Error: File not found

D

Warning: Low memory
Error: Access denied

💡 Hint

Select-String finds all lines containing the pattern.

Select-String searches the file and returns all lines that contain the word 'Error'. Here, two lines match.

💻 Command Output

intermediate

What does this Select-String command output?

Consider this command:

Get-Content data.txt | Select-String -Pattern '^Start'

If data.txt contains:

End of file
Start of process
Starting point
Stop here

What lines will be output?

PowerShell

Get-Content data.txt | Select-String -Pattern '^Start'

A Start of process

B

End of file
Stop here

C

Start of process
Starting point

D Starting point

💡 Hint

The caret ^ matches the start of a line.

The pattern '^Start' matches lines that begin with 'Start'. Only 'Start of process' matches because 'Starting point' starts with 'Starting', not 'Start' exactly at the start.

🔧 Debug

advanced

Why does this Select-String command fail?

You run this command:

Select-String -Path 'C:\Logs\app.log' -Pattern Error -CaseSensitive

But it returns an error:

Select-String : A parameter cannot be found that matches parameter name 'CaseSensitive'.

What is the cause?

PowerShell

Select-String -Path 'C:\Logs\app.log' -Pattern Error -CaseSensitive

A The file path is incorrect, causing the error.

B The pattern 'Error' must be in quotes.

C The '-CaseSensitive' parameter does not exist; use '-CaseSensitive' as a switch is invalid.

D Select-String requires '-IgnoreCase' instead of '-CaseSensitive'.

💡 Hint

Check the official parameters of Select-String.

Select-String does not have a '-CaseSensitive' parameter. To do case-sensitive search, use '-CaseSensitive' switch in PowerShell 7+, or use regex with '(?i)' for ignore case.

🚀 Application

advanced

How to find lines NOT containing a pattern using Select-String?

You want to find all lines in server.log that do NOT contain the word 'Warning'. Which command achieves this?

A Select-String -Path server.log -Pattern '.*' | Where-Object { $_.Line -notmatch 'Warning' }

B Select-String -Path server.log -Pattern 'Warning' -NotMatch

C Select-String -Path server.log -Pattern 'Warning' -NotMatch $true

D Select-String -Path server.log -Pattern 'Warning' -NotMatch $false

💡 Hint

Select-String does not have a '-NotMatch' parameter.

Select-String does not support '-NotMatch'. Instead, filter results with Where-Object to exclude lines matching the pattern.

🧠 Conceptual

expert

What is the count of matches from this Select-String command?

Given a file data.txt with 5 lines:

apple
banana
Apple pie
APPLE
pineapple

What is the output of:

(Select-String -Path data.txt -Pattern 'apple' -AllMatches).Matches.Count

PowerShell

(Select-String -Path data.txt -Pattern 'apple' -AllMatches).Matches.Count

A 1

B 3

C 5

D 4

💡 Hint

By default, Select-String is case-insensitive.

By default, Select-String is case-insensitive. The pattern 'apple' matches 'apple' (line1), 'Apple' in 'Apple pie' (line3), 'APPLE' (line4), and 'apple' in 'pineapple' (line5). With -AllMatches, .Matches collects all individual matches across all lines, and .Count gives the total: 4.