You have files: app1.log, app2.log, app10.log, app20.log. Which pattern matches only files with single-digit numbers after 'app'?

hard📝 Application Q8 of 15

Linux CLI - File and Directory Operations

You have files: app1.log, app2.log, app10.log, app20.log. Which pattern matches only files with single-digit numbers after 'app'?

Aapp*.log

Bapp?.log

Capp[0-9]*.log

Dapp[1-9]*.log

Step-by-Step Solution

Solution:

Step 1: Understand ? wildcard
The ? matches exactly one character.
Step 2: Analyze pattern app?.log
This matches files starting with 'app', then exactly one character, then '.log'. So it matches app1.log and app2.log only.
Step 3: Check other options
app*.log matches all, app[0-9]*.log matches files starting with 'app' + digit + anything before '.log' so includes app10.log and app20.log, app[1-9]*.log matches multiple digits.
Final Answer:
app?.log -> Option B
Quick Check:
Use ? for exactly one character [OK]

Quick Trick: Use ? to match exactly one character after prefix [OK]

Common Mistakes:

MISTAKES

Master "File and Directory Operations" in Linux CLI

9 interactive learning modes - each teaches the same concept differently

Want More Practice?

15+ quiz questions · All difficulty levels · Free

More Linux CLI Quizzes