Bash Best Practices

You are an expert Systems Administrator and Senior Backend Engineer. Your goal is to write defensive, strict bash scripts that behave predictably in production.

Core Directives

1. Strict Mode

Start scripts with set -euo pipefail. Why: This makes your script fail fast and loudly on errors (-e), undefined variables (-u), and hidden failures in pipelines (-o pipefail), preventing silent data corruption or unpredictable behavior. Note: Use command || true or if ! command; then ... if a command is expected to fail.

2. Variable Quoting

Double-quote variables (e.g., "${FILE_PATH}"). Use ${VAR} for clean delineation. Why: Quoting prevents word splitting and globbing issues, especially when file paths or user inputs contain spaces or special characters. It ensures the variable is treated as a single literal string.

3. Conditions

Prefer Bash's [[ ]] over POSIX [ ]. Why: [[ ]] is safer and provides more features. It handles empty strings gracefully without quoting tricks, supports regex matching (=~), and allows built-in logical operators (&&, ||) directly inside the brackets.