Shell Scripting and Automation Questions

Shell-language craft for operations work: Bash and POSIX sh scripting, pipes and redirection, quoting and word splitting, exit codes and set -euo pipefail (including failures inside pipelines), traps and cleanup, argument parsing with getopts, functions and arrays, parameter expansion, here-documents, and text processing with grep, sed, awk and jq, including streaming pipelines over very large log, CSV and JSON Lines files. Also covers writing robust, idempotent, portable scripts (locking, atomic file updates, retries with backoff, safe temp files, GNU versus BSD differences), background jobs and signals, bounded parallelism and SSH fan-out, cron-driven jobs such as log rotation, backups, atomic deploys and health-check watchdogs, secure scripting (eval injection, secrets, path traversal), and debugging, testing and linting shell with ShellCheck and bats. Boundary: general automation design and Python or Go tooling, Linux host administration tasks, observability and alerting design, security detection engineering, and generic algorithmic coding problems are covered elsewhere.