arnesto: Skill for Claude Code

.agents/skills/writing-bash-scripts/SKILL.md

writing-bash-scripts is a skill for Claude Code, Codex from saski/arnesto. It costs 27 tokens per session (128 once invoked), scanned A, a copy of writing-bash-scripts, Unlicense.

A style guide for writing Bash and shell scripts, covering safe defaults, input checks, concise logic, and executable setup.

In plain words
What is it for?
Use it when creating or updating Bash scripts, shell utilities, or command-line tools.
Why use it?
It helps avoid common script failures and keeps command-line tools consistent and easier to read.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: installed under .agents/ (shared by several agents).

This is saski/arnesto's own configuration. It tells Claude Code and Codex how to work on arnesto itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything arnesto configures →

Reuse

Borrowing it

Nothing to install: this file belongs to saski/arnesto. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/saski/arnesto/main/.agents/skills/writing-bash-scripts/SKILL.md
Clone the repo
git clone --depth 1 https://github.com/saski/arnesto

Made for: Claude Code, Codex.

Wrote 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.

agentmods badge for writing-bash-scripts

README.md
[![agentmods](https://agentmods.dev/badge/skills/saski/arnesto/writing-bash-scripts.svg)](https://agentmods.dev/skills/saski/arnesto/writing-bash-scripts)
Your own site
<a href="https://agentmods.dev/skills/saski/arnesto/writing-bash-scripts"><img src="https://agentmods.dev/badge/skills/saski/arnesto/writing-bash-scripts.svg" alt="Measured on agentmods" height="20"></a>
Per session 27 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 128 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin 100% copy Near-identical to another mod in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00027 $0.00128
Opus 5 $0.00014 $0.00064
Sonnet 5 $0.00005 $0.00026
Haiku 4.5 $0.00003 $0.00013

Measured 3d ago against content hash 54d6db990e37, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

writing-bash-scripts 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 3d 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.

Origin

This is a copy

100% identical to writing-bash-scripts — 0 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

.agents/skills/writing-bash-scripts/SKILL.md · 15 lines

What it actually says

Bash Script Style Guide

  • Use #!/usr/bin/env bash as shebang
  • Always use set -euo pipefail for safety
  • Keep scripts minimal: no unnecessary comments or echoes
  • Minimal input validation; print usage to stderr and exit if inputs are missing/invalid
  • Don't check for installed commands if failure is obvious on use
  • Make script executable: chmod +x <script>
  • Prefer concise, direct logic over verbosity
Changes

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.

  1. 3d ago First seen · 15 lines · 27 tokens per session scan A 54d6db990e37

Subscribe to this mod's changes

writing-bash-scripts is a skill published in the GitHub repository saski/arnesto (5 stars, last pushed today), licensed Unlicense. It adds 27 tokens to every session and 128 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. It is 100% identical to writing-bash-scripts, differing in 0 lines, and is treated as a copy.