🌈 log-pretty

Transform raw logs into beautiful, human-readable output — instantly.

# Before — raw JSON log
{"timestamp":"2026-04-24T22:38:51Z","level":"error","message":"DB timeout","code":503,"retry":true}

# After — log-pretty output
2026-04-24T22:38:51Z [ERROR]
  Message: DB timeout
  Code: 503
  Retry: true

✨ Features

	Feature	Description
🎨	Colorized levels	`DEBUG`=cyan · `INFO`=green · `WARN`=yellow · `ERROR`=red · `FATAL`=magenta
📋	Structured output	Indented, field-by-field display — scan logs at a glance
🔄	Auto-detect format	Parses JSON and plain-text logs automatically
🔧	CLI pipe tool	`tail -f app.log \	log-pretty` — works anywhere
📚	Ruby library	Embed directly in your Ruby app or Rack middleware
⚡	Minimal footprint	Only one runtime dependency: rainbow

📦 Installation

Via RubyGems (recommended)

gem install pretty_logs

Via Bundler

Add to your Gemfile:

gem 'pretty_logs'

Then:

bundle install

From Source

git clone https://github.com/brijeshsajeev/log-pretty
cd log-pretty/pretty_logs
bundle install
bundle exec rake install

🚀 CLI Usage

log-pretty reads from stdin and writes prettified output to stdout.

# Pipe a file
log-pretty < app.log

# Tail live logs
tail -f production.log | log-pretty

# Pipe from a running process
docker logs -f my-container | log-pretty
rails server 2>&1 | log-pretty

Options

Flag	Description
`-f`, `--format FORMAT`	Force format: `auto` (default), `json`, `plain`
`-s`, `--simple`	Single-line output instead of structured
`-c`, `--[no-]color`	Enable/disable colors (default: enabled)
`-h`, `--help`	Show help

Examples

JSON log:

echo '{"timestamp":"2026-04-24T22:38:51Z","level":"info","message":"User logged in","user_id":123}' | log-pretty
# 2026-04-24T22:38:51Z [INFO]
#   Message: User logged in
#   User_id: 123

Plain-text log:

echo '2026-04-24T22:38:51Z [ERROR] Connection timeout' | log-pretty
# 2026-04-24T22:38:51Z [ERROR]
#   Message: Connection timeout

Simple single-line output:

tail -f app.log | log-pretty --simple
# 2026-04-24T22:38:51Z [INFO] Application started
# 2026-04-24T22:38:52Z [WARN] High memory usage

No colors (for log files / CI):

log-pretty --no-color < app.log > cleaned.log

📚 Ruby Library Usage

require 'pretty_logs'

formatter = PrettyLogs::Formatter.new(structured: true)

# Format a hash directly
entry = {
  timestamp: "2026-04-24T22:38:51Z",
  level: "info",
  message: "Processing request",
  request_id: "abc123",
  duration_ms: 42
}
puts formatter.format(entry)
# 2026-04-24T22:38:51Z [INFO]
#   Message: Processing request
#   Request_id: abc123
#   Duration_ms: 42

# Parse and format a JSON log line
json_line = '{"level":"error","message":"Database error","code":500}'
parsed = PrettyLogs::Parsers::JsonParser.parse(json_line)
puts formatter.format(parsed)

# Parse and format a plain-text log line
plain_line = "2026-04-24T22:38:51Z [WARN] High memory usage"
parsed = PrettyLogs::Parsers::PlainTextParser.parse(plain_line)
puts formatter.format(parsed)

📋 Supported Log Formats

JSON Logs

Any valid JSON object. Recognized fields:

Field	Description
`timestamp`	ISO 8601 timestamp
`level`	Log level (`debug`, `info`, `warn`, `error`, `fatal`)
`message`	Log message
any other field	Displayed as additional structured data

Plain-Text Logs

YYYY-MM-DDTHH:MM:SS[.mmm][Z|±HH:MM] [LEVEL] Message text

Examples:

2026-04-24T22:38:51Z [INFO] Application started
2026-04-24T22:38:51.123Z [ERROR] Connection failed
2026-04-24T22:38:51.000+05:30 [DEBUG] Cache miss for key=user:42

🎨 Log Level Colors

Level	Color	Example use
`DEBUG`	Cyan	Low-level diagnostics
`INFO`	Green	Normal operations
`WARN` / `WARNING`	Yellow	Something may need attention
`ERROR`	Red	Something failed
`FATAL`	Magenta	Critical failure

🔧 CI / Automation Usage

Disable colors for clean output in CI pipelines:

# GitHub Actions, Jenkins, etc.
cat build.log | log-pretty --no-color

# Or via env (Rainbow respects NO_COLOR)
NO_COLOR=1 log-pretty < app.log

🛠 Development

git clone https://github.com/brijeshsajeev/log-pretty
cd log-pretty/pretty_logs
bundle install

bundle exec rspec          # Run test suite
bundle exec log-pretty     # Test CLI manually

🧪 Testing

bundle exec rspec

14 examples, 0 failures  ✅

📄 License

🤝 Contributing

Bug reports and pull requests are welcome on GitHub.

Fork the repository
Create your branch: git checkout -b feature/my-feature
Add tests for your changes
Run bundle exec rspec — all tests must pass
Submit a Pull Request

Made with ❤️ by Brijesh S A