name: shell-coding description: Guidance for writing and debugging shell scripts (Bash/Zsh). Use this when asked to create or fix shell scripts, automate tasks, or manage system configurations via shell commands.

Shell Coding Skill and Rules

Overall rules

Always start with set -euo pipefail - Exit on errors (-e), undefined variables (-u), and pipeline failures (-o pipefail) to catch bugs early.

Quote all variables - Use "$var" instead of $var to prevent word splitting and glob expansion issues with spaces or special characters.

Use [[ ]] instead of [ ] - Double brackets provide safer string comparisons, support regex, and avoid pitfalls with empty variables.

Input validation

Check that required arguments exist and commands are available before proceeding (e.g., command -v jq >/dev/null || { echo "jq required"; exit 1; }).

Function creations

Organize code into functions with descriptive names to improve readability and maintainability.