rslog

A lightweight, zero-dependency logging library for Rust, built entirely using the standard library.

Features

• Zero Dependencies: Built entirely using Rust's standard library
• Multiple Log Levels: Debug, Info, Warn, Error, Critical
• Multiple Output Targets: Console and file output
• Async Writing: Background thread for non-blocking file writes
• Log Rotation: Size-based and time-based rotation
• Multiple Output Formats: Text, JSON, and custom patterns
• Configurable: Flexible configuration options

Quick Start

Add rslog to your Cargo.toml:

[dependencies]
rslog = { path = "path/to/rslog" }

Basic Usage

use rslog::{Logger, LogLevel};

fn main() {
    // Get the logger instance
    let logger = Logger::get_instance();
    
    // Log messages at different levels
    logger.debug("Debug message");
    logger.info("Application started");
    logger.warn("Low memory warning");
    logger.error("Connection failed");
    logger.critical("System shutdown");
}

Custom Configuration

use rslog::{Logger, LogLevel, ConfigBuilder, OutputFormat};

fn main() {
    // Build a custom configuration
    let config = ConfigBuilder::new()
        .log_dir("logs")
        .file_prefix("app_")
        .level(LogLevel::Info)
        .output_format(OutputFormat::Json)
        .build();
    
    // Initialize logger with custom config
    Logger::init_with_config(config);
    
    let logger = Logger::get_instance();
    logger.info("Hello, world!");
}

Log Rotation

use rslog::{Logger, ConfigBuilder, RotationStrategy, RotatorConfig};

fn main() {
    let config = ConfigBuilder::new()
        .rotation(RotatorConfig {
            strategy: RotationStrategy::SizeBased(10 * 1024 * 1024), // 10MB
            max_files: 5,
            compress_old_files: false,
        })
        .build();
    
    Logger::init_with_config(config);
    let logger = Logger::get_instance();
}

Output Formats

Text Format (Default)

[2026-05-09 10:30:45.123456789] [INFO] Application started

JSON Format

{"time":"2026-05-09 10:30:45.123456789","level":"INFO","message":"Application started"}

Custom Format

use rslog::{ConfigBuilder, OutputFormat};

let config = ConfigBuilder::new()
    .output_format(OutputFormat::Custom("%D %T [%P] %m".to_string()))
    .build();

Custom Format Placeholders

Configuration Options

Log Levels

Examples

Run the example:

cargo run --example test

Documentation

Generate documentation:

cargo doc --open

License

MIT License

Contributing

Contributions are welcome! Please feel free to submit issues and pull requests.