r3bl-open-core: Skill for Claude Code

.agents/skills/analyze-log-files/SKILL.md

analyze-log-files is a skill for Claude Code, Codex from r3bl-org/r3bl-open-core. It costs 36 tokens per session (642 once invoked), scanned B, original, Apache-2.0.

A guide for analyzing log files that may contain ANSI escape codes, the hidden characters terminals use for colors, cursor movement, and screen control.

In plain words
What is it for?
Use it when reading, processing, or investigating terminal logs that look garbled or contain formatting artifacts.
Why use it?
Removing those codes first makes captured terminal logs readable and prevents them from interfering with searching or analysis.

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 r3bl-org/r3bl-open-core's own configuration. It tells Claude Code and Codex how to work on r3bl-open-core 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 r3bl-open-core configures →

Reuse

Borrowing it

Nothing to install: this file belongs to r3bl-org/r3bl-open-core. 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/r3bl-org/r3bl-open-core/main/.agents/skills/analyze-log-files/SKILL.md
Clone the repo
git clone --depth 1 https://github.com/r3bl-org/r3bl-open-core

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 analyze-log-files

README.md
[![agentmods](https://agentmods.dev/badge/skills/r3bl-org/r3bl-open-core/analyze-log-files/github.svg)](https://agentmods.dev/skills/r3bl-org/r3bl-open-core/analyze-log-files)
Your own site
<a href="https://agentmods.dev/skills/r3bl-org/r3bl-open-core/analyze-log-files"><img src="https://agentmods.dev/badge/skills/r3bl-org/r3bl-open-core/analyze-log-files/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.

agentmods 80×15 button for analyze-log-files

Your own site · 80×15
<a href="https://agentmods.dev/skills/r3bl-org/r3bl-open-core/analyze-log-files"><img src="https://agentmods.dev/badge/skills/r3bl-org/r3bl-open-core/analyze-log-files.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 36 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 642 The whole file, excluding the scripts and references it only reads on demand.
Security scan B 1 finding. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector warn 7 Sept 2026
SkillSpector: 1 finding, up to medium

These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →

  • medium Privilege Escalation · line 79
    Commands invoke sudo or root privileges. Verify this elevated access is necessary and justified.
    Fix: Avoid sudo/root unless strictly required. Prefer least-privilege patterns. If elevation is needed, document the justification and scope.
How audits are shown
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 5.1 $0.00036 $0.00642
Opus 5 $0.00018 $0.00321
Sonnet 5 $0.00007 $0.00128
Haiku 4.5 $0.00004 $0.00064

Measured 12d ago against content hash a4dd6666e838, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade B, and why

analyze-log-files scanned grade B with 1 finding 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 12d 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.

Asks for rootmediumPrivilege escalation

A mod that escalates privileges can change anything on the machine, not only the project.

sudo apt-get install ansifilter
.agents/skills/analyze-log-files/SKILL.md · 96 lines

How it starts

The opening of the file, as written. The whole thing — 96 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Analyze Log Files

When to Use

  • When user asks to "analyze /tmp/r3bl_tui/log.txt", "read the log file", "process logs", "check the logs"
  • When dealing with any .log or log-related files that may contain ANSI escape sequences
  • When terminal output has been captured to a file and needs analysis
  • When log files appear garbled or contain escape sequence artifacts

Why This Matters

Log files captured from terminal sessions often contain ANSI escape sequences for:

  • Colors (e.g., \x1b[31m for red)
  • Cursor movements
  • Text formatting (bold, underline)
  • Screen clearing commands

These sequences make logs difficult to:

  1. Read in plain text editors
  2. Search with grep/ripgrep
  3. Process with text analysis tools
  4. Analyze accurately by LLMs

Instructions

Step 1: Strip ANSI Escape Sequences

Before analyzing any log file, first strip the ANSI sequences using ansifilter:

ansifilter -i /tmp/r3bl_tui/log.txt -o /tmp/clean_log.txt

For other log file names, adjust accordingly:

ansifilter -i <input_file> -o /tmp/clean_log.txt

Step 2: Analyze the Clean Log

Read and analyze /tmp/clean_log.txt instead of the original file:

# Use the Read tool on /tmp/clean_log.txt

Step 3: Report Findings

When reporting findings to the user:

  • Reference line numbers from the clean log
  • Quote relevant sections
  • Summarize errors, warnings, or patterns found

Common Log File Locations

  • /tmp/r3bl_tui/log.txt - General purpose log in project root
  • target/ - Cargo build logs
  • /tmp/*.log - Temporary logs

Example Workflow

User: "Can you analyze /tmp/r3bl_tui/log.txt and tell me what's wrong?"

  1. Run: ansifilter -i /tmp/r3bl_tui/log.txt -o /tmp/clean_log.txt
  2. Read: /tmp/clean_log.txt
  3. Analyze the content for errors, warnings, patterns
  4. Report findings to user

Troubleshooting

If ansifilter is not installed:

# Ubuntu/Debian
sudo apt-get install ansifilter

# macOS
brew install ansifilter

# Or run bootstrap.sh to install all dependencies
./bootstrap.sh

Read the full file on GitHub · 96 lines

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. 12d ago First seen · 96 lines · 36 tokens per session scan B a4dd6666e838

Subscribe to this mod's changes

analyze-log-files is a skill published in the GitHub repository r3bl-org/r3bl-open-core (483 stars, last pushed today), licensed Apache-2.0. It adds 36 tokens to every session and 642 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it B with 1 finding (asks for root). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

Related

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