essay
hard
Analyze
evaluation-order
2 points
Question 40. CSCD240-E1-A
sort data.txt > data.txt — what happens to data.txt and why?
Work the drill
Answer on paper or in a terminal before revealing the ideal answer.
Ideal answer
data.txt becomes empty. The shell evaluates > data.txt FIRST (truncating), then sort reads an empty file and writes nothing back.
Misconception bank
Each row below is a plausible wrong answer, the thinking that produces it, and the remedy that corrects the misconception. These are the foundation of the multiple-choice framing and the targeted feedback a student receives after answering.
File is sorted
Misconception. Expects sort-in-place; missing the clobber rule.
Remedy. Teach shell redirection evaluation order; use sort -o for in-place.
sort errors out
Misconception. Some shells might, but bash does not — it truncates silently.
Remedy. Demo the actual behavior.
Authority mappings
Hover any chip for the mapping justification; click to open the authority record.
DCWF roles:
IT-451 System Administrator
DCWF tasks:
T0498
KU outcomes:
CD-CSP-O4
Course-artifact links
Lectures
- CSCD240-S26-L07. I/O redirection, aliases, source, .bashrc, env
CTF challenges
- 03 I/O & Pipelines: where data