shell-scripting

Guidance for writing Bash and other shell scripts, which are command-line programs used to automate computer tasks.

In plain words
What is it for?
Writing and debugging Bash scripts, managing running processes, automating tasks, and developing command-line tools.
Why use it?
It helps scripts handle errors, processes, and edge cases safely instead of failing unexpectedly during automation.

Skill for Claude CodeCodex

Install

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.

agentmods
npx agentmods add skills/futurejj/claude-skills/shell-scripting
Any agent
npx skills add FutureJJ/claude-skills --skill shell-scripting
Clone the repo
git clone --depth 1 https://github.com/FutureJJ/claude-skills

Made for: Claude Code, Codex.

Per session 35 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 182 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found 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 $0.00035 $0.00182
Opus 5 $0.00017 $0.00091
Sonnet 5 $0.00007 $0.00036
Haiku 4.5 $0.00003 $0.00018

Measured 2d ago against content hash 573202f33246, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

shell-scripting 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 2d 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

Copies of this mod

1 near-identical copy found in the catalogue:

skills/shell-scripting/SKILL.md · 29 lines

What it actually says

Shell Scripting

You are an expert in shell scripting focused on production-grade solutions.

Core Principles

  • Follow industry best practices and proven patterns
  • Optimize for maintainability and reliability
  • Document decisions and trade-offs
  • Measure before optimizing

Anti-Patterns

  • Over-engineering simple solutions
  • Ignoring error handling and edge cases
  • Copying patterns without understanding context
  • Premature optimization without profiling

Reference Guide

Topic Reference Load When
Core patterns references/patterns.md Common patterns and best practices
Advanced topics references/advanced.md Complex scenarios and optimization
Files

What ships with it

2 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.

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. 2d ago First seen · 29 lines · 35 tokens per session scan A 573202f33246

Subscribe to this mod's changes

shell-scripting is a skill published in the GitHub repository FutureJJ/claude-skills (3 stars, last pushed 5mo ago), licensed MIT. It adds 35 tokens to every session and 182 once invoked, about $0.0002 per session on Opus 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 2026-08-31.

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