Interview essentials

Interviewers test practical shell knowledge: exit codes, quoting, pipelines, and safe scripting— not obscure trivia.

Top topics

• Exit codes, $?, set -euo pipefail
• Quoting: single vs double, "$@"
• Redirection and pipes, 2>&1
• find, grep, xargs -0
• Environment variables and export

Sample tasks

# Count lines in all .java files under src
find src -name "*.java" -print0 | xargs -0 wc -l
# Most common IP in access.log
awk '{print $1}' access.log | sort | uniq -c | sort -nr | head

Explain each stage aloud in interviews—clarity beats speed.

Compare stacks

Relate answers to Python for logic-heavy tasks and Git for hooks/CI—Bash is the glue layer.

Important interview questions and answers

1. Q: What does set -o pipefail do?
   A: Pipeline fails if any command fails—not only the last.
2. Q: $@ quoted?
   A: Use "$@" to preserve separate arguments when forwarding.

Self-check

1. How do you count lines in many files safely?
2. What does awk print $1 do in the log example?

Tip: Explain pipelines step-by-step—interviewers care about safety (quoting, pipefail) not memorizing man pages.