Interview › Scripting (Bash, Groovy)
What is /dev/null, and why redirect to it? [Intermediate]
Answer
/dev/null is a special device that discards anything written to it and returns EOF when read. I redirect to it when I intentionally want to suppress output, while still checking the command's exit code.
Technical explanation
It is useful for quiet existence checks, health checks, and commands whose output is irrelevant.
Do not hide errors blindly in production scripts; suppress output only when failures are handled or logged elsewhere.
Redirect stdout only with >/dev/null, stderr only with 2>/dev/null, or both with >/dev/null 2>&1.
Hands-on example
if command -v kubectl >/dev/null 2>&1; then
echo "kubectl is installed"
else
echo "kubectl is missing" >&2
fi
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