Interview › Scripting (Bash, Groovy)
How do you create a secure temporary file or directory (mktemp)? [Intermediate]
Answer
I use mktemp to create unpredictable temporary files or directories safely. This avoids race conditions and symlink attacks that can happen with predictable names like /tmp/myfile.$$.
Technical explanation
mktemp creates the file or directory with a unique name and safe permissions.
For multiple files, create a temporary directory with mktemp -d and place files inside it.
Always register cleanup with trap unless the temp artifact must be preserved for debugging.
Hands-on example
tmpdir=$(mktemp -d)
trap 'rm -rf "$tmpdir"' EXIT
config="$tmpdir/config.yaml"
cat > "$config" <<'EOF'
name: demo
EOF
run_tool --config "$config
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