# Tailspin — Log File Highlighter for the Terminal

> Tailspin is a command-line log file highlighter written in Rust that automatically detects and colorizes dates, IPs, UUIDs, HTTP methods, log levels, and other common patterns to make log reading faster.

## Install

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# Tailspin — Log File Highlighter for the Terminal

## Quick Use
```bash
# Install on macOS
brew install tailspin

# Install via Cargo
cargo install tailspin

# Highlight a log file
tspin /var/log/syslog

# Pipe any output through Tailspin
kubectl logs deployment/api | tspin

# Follow a log file with highlighting
tspin -f /var/log/app.log
```

## Introduction
Tailspin is a Rust-based CLI tool that adds instant syntax highlighting to any log output. Unlike grep or less, Tailspin automatically detects common log patterns — timestamps, IP addresses, UUIDs, HTTP methods, URLs, log levels, and key-value pairs — and colorizes them without any configuration. It works as a drop-in replacement for tail or less when reading logs.

## What Tailspin Does
- Automatically highlights dates, IPs, UUIDs, URLs, numbers, and log levels
- Works with any log format without requiring format-specific configuration
- Supports piping from any command (kubectl, docker, journalctl, cat)
- Follows log files in real time with the -f flag like tail -f
- Provides a built-in pager for scrolling through large files

## Architecture Overview
Tailspin is a single Rust binary that reads input line by line and applies a series of regex-based highlighters. Each highlighter matches a specific pattern type (ISO timestamps, IPv4/IPv6, severity keywords) and wraps matches in ANSI color codes. The matching pipeline is optimized for throughput so it does not bottleneck high-volume log streams. Output is rendered to the terminal or piped through a pager.

## Self-Hosting & Configuration
- Install as a single static binary; no runtime dependencies
- Custom highlight rules can be added via a TOML config file at ~/.config/tailspin/config.toml
- Override default colors by specifying custom ANSI color codes per pattern type
- Disable specific highlighters with --disable flag
- Integrates with any terminal that supports ANSI escape codes

## Key Features
- Zero-config highlighting for the most common log patterns
- High-throughput line processing that keeps up with streaming logs
- Built-in pager with search support (press / to search)
- Custom highlight groups definable in TOML configuration
- Works over SSH and in containers where GUI tools are unavailable

## Comparison with Similar Tools
- **ccze** — C-based log colorizer with format-specific parsers; Tailspin is format-agnostic
- **lnav** — full log navigator with indexing and SQL queries; Tailspin focuses purely on highlighting
- **grc** — generic colourizer using regex config files; Tailspin needs no configuration for common patterns
- **bat** — syntax-highlighted cat for code files; Tailspin specializes in log file patterns
- **less** — standard pager without colors; Tailspin adds automatic log-aware highlighting

## FAQ
**Q: Does Tailspin work with JSON logs?**
A: Yes. It highlights JSON keys, values, timestamps, and other patterns within JSON-formatted log lines.

**Q: Can I use Tailspin as a pager for other commands?**
A: Yes. Pipe any command output through tspin to get instant highlighting with a built-in pager.

**Q: Does it slow down high-volume log tailing?**
A: No. Tailspin is written in Rust and processes lines at speeds well above typical log throughput rates.

**Q: How do I add custom patterns?**
A: Add regex rules and ANSI color codes to the [groups] section in ~/.config/tailspin/config.toml.

## Sources
- https://github.com/bensadeh/tailspin

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