Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add xonovex/platform --skill shell-scripting-guidegit clone --depth 1 https://github.com/xonovex/platformWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/xonovex/platform/shell-scripting-guide)<a href="https://agentmods.dev/skills/xonovex/platform/shell-scripting-guide"><img src="https://agentmods.dev/badge/skills/xonovex/platform/shell-scripting-guide/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/xonovex/platform/shell-scripting-guide"><img src="https://agentmods.dev/badge/skills/xonovex/platform/shell-scripting-guide.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00086 | $0.00679 |
| Opus 5.5 | $0.00034 | $0.00272 |
| Sonnet 5.5 | $0.00017 | $0.00136 |
| Haiku 4.5 | $0.00009 | $0.00068 |
Grade A, and why
shell-scripting-guide scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 7d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 38 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Shell Scripting Coding Guidelines
Write portable shell scripts with quoted arguments, explicit failure handling, and ShellCheck and shfmt validation.
Essentials
- POSIX compatibility - Use POSIX sh, lint with shellcheck, format with shfmt, see references/posix-compatibility.md
- Strict mode - Use strict mode and safe defaults, see references/strict-mode.md
- Quoting - Quote all expansions to avoid word splitting, see references/quoting.md
- Functions - Write small, focused functions, see references/functions.md
- Parameter expansion - Set default values and manipulate variables, see references/parameter-expansion.md
- Error handling - Implement exit codes and error messages, see references/error-handling.md
- Idempotency - Make scripts safely re-runnable, see references/idempotency.md
Gotchas
- Unquoted variables word-split and glob-expand:
cp $file dest/silently breaks on filenames with spaces; quote everything set -edoesn't catch errors insideif,&&,||, or pipelines without-o pipefail: combineset -euo pipefailat the top
Progressive disclosure
- Read references/posix-compatibility.md - Load when ensuring portability across shells
- Read references/strict-mode.md - Load when setting up error handling and safety flags
- Read references/quoting.md - Load when variables expand incorrectly or word splitting occurs
- Read references/functions.md - Load when organizing script logic or creating reusable code
- Read references/parameter-expansion.md - Load when setting default values or manipulating variables
- Read references/error-handling.md - Load when implementing exit codes or error messages
- Read references/argument-parsing.md - Load when parsing command-line flags or arguments
- Read references/validation.md - Load when checking preconditions or input validity
- Read references/idempotency.md - Load when scripts should be safely re-runnable
- Read references/common-patterns.md - Load when learning common shell idioms
- Read references/script-template.md - Load when starting a new shell script
What ships with it
15 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
- eval-queries.json 5.2 KB
- evals.json 2.5 KB
- moon.yml 166 B
- references/argument-parsing.md 617 B
- references/common-patterns.md 228 B
- references/error-handling.md 289 B
- references/functions.md 509 B
- references/idempotency.md 156 B
- references/parameter-expansion.md 622 B
- references/posix-compatibility.md 395 B
- references/quoting.md 449 B
- references/script-template.md 572 B
- references/strict-mode.md 328 B
- references/validation.md 479 B
- SOURCES.md 569 B
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 7d ago Changed · +2 lines d9b2efcecda9
- 1mo ago First seen · 36 lines · 86 tokens per session scan A d92f0dda6945
shell-scripting-guide is a skill published in the GitHub repository xonovex/platform (6 stars, last pushed 5d ago), licensed MIT. It adds 86 tokens to every session and 679 once invoked, about $0.0003 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-08.
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