rumdl 0.0.16

An extremely fast Markdown linter written in Rust

rumdl - An extremely fast Markdown linter, written in Rust

An extremely fast Markdown linter and formatter, written in Rust.

Docs | Rules | Configuration

Table of Contents

• rumdl - An extremely fast Markdown linter, written in Rust
  • Table of Contents
  • Overview
  • Installation
    • Using Cargo (Rust)
    • Using pip (Python)
    • Download binary
  • Usage
  • Rules
  • Command-line Interface
    • Commands
    • Options
  • Configuration
  • Output Style
    • Output Format
  • Development
    • Prerequisites
    • Building
    • Testing
  • License

Overview

rumdl is a lightning-fast Markdown linter and fixer that helps ensure consistency and best practices in your Markdown files. It offers:

• ⚡️ 10-50x faster than other Markdown linters
• 🔍 50+ lint rules covering common Markdown issues
• 🛠️ Automatic fixing with --fix for most rules
• 📦 Zero dependencies - single binary with no runtime requirements
• 🔧 Highly configurable with TOML-based config files
• 🌐 Multiple installation options - Rust, Python, standalone binaries
• 📏 Modern CLI with detailed error reporting
• 🔄 CI/CD friendly with non-zero exit code on errors

Installation

Choose the installation method that works best for you:

Using Cargo (Rust)

cargo install rumdl

Using pip (Python)

pip install rumdl

Download binary

# Linux/macOS
curl -LsSf https://github.com/user/rumdl/releases/latest/download/rumdl-linux-x86_64.tar.gz | tar xzf - -C /usr/local/bin

# Windows PowerShell
Invoke-WebRequest -Uri "https://github.com/user/rumdl/releases/latest/download/rumdl-windows-x86_64.zip" -OutFile "rumdl.zip"
Expand-Archive -Path "rumdl.zip" -DestinationPath "$env:USERPROFILE\.rumdl"

Usage

Getting started with rumdl is simple:

# Check a single file
rumdl README.md

# Check all Markdown files in current directory and subdirectories
rumdl .

# Automatically fix issues
rumdl --fix README.md

# Create a default configuration file
rumdl init

Common usage examples:

# Check with custom configuration
rumdl --config my-config.toml docs/

# Disable specific rules
rumdl --disable MD013,MD033 README.md

# Enable only specific rules
rumdl --enable MD001,MD003 README.md

# Exclude specific files/directories
rumdl --exclude "node_modules,dist" .

Rules

rumdl implements over 50 lint rules for Markdown files. Here are some key rule categories:

Category	Description	Example Rules
Headings	Proper heading structure and formatting	MD001, MD002, MD003
Lists	Consistent list formatting and structure	MD004, MD005, MD007
Whitespace	Proper spacing and line length	MD009, MD010, MD012
Code	Code block formatting and language tags	MD040, MD046, MD048
Links	Proper link and reference formatting	MD034, MD039, MD042
Images	Image alt text and references	MD045, MD052
Style	Consistent style across document	MD031, MD032, MD035

For a complete list of rules and their descriptions, see our documentation or run:

rumdl --list-rules

Command-line Interface

rumdl [options] [file or directory...]
rumdl <command> [options]

Commands

• init: Create a default .rumdl.toml configuration file in the current directory

Options

• -c, --config <file>: Use custom configuration file
• -f, --fix: Automatically fix issues where possible
• -l, --list-rules: List all available rules
• -d, --disable <rules>: Disable specific rules (comma-separated)
• -e, --enable <rules>: Enable only specific rules (comma-separated)
• --exclude <patterns>: Exclude specific files or directories (comma-separated glob patterns)
• --respect-gitignore: Respect .gitignore files when scanning directories
• -v, --verbose: Show detailed output

Configuration

rumdl can be configured using a TOML configuration file. By default, it looks for rumdl.toml or .rumdl.toml in the current directory.

You can create a default configuration file using the init command:

rumdl init

This will create a .rumdl.toml file in the current directory with default settings that you can customize.

Example configuration file:

# Global configuration options
[global]
# List of rules to disable
disable = ["MD013", "MD033"]

# List of rules to enable exclusively (if provided, only these rules will run)
# enable = ["MD001", "MD003", "MD004"]

# List of file/directory patterns to exclude from linting
exclude = [
    # Common directories to exclude
    ".git",
    ".github",
    "node_modules",
    "vendor",
    "dist",
    "build",

    # Specific files or patterns
    "CHANGELOG.md",
    "LICENSE.md",
    "generated/*.md",
    "**/temp_*.md",
]

# Whether to respect .gitignore files when scanning directories
respect_gitignore = false

# Rule-specific configurations
[MD002]
level = 1  # Expected level for first heading

[MD003]
style = "atx"  # Heading style (atx, atx_closed, setext)

Output Style

rumdl produces clean, colorized output similar to modern linting tools:

README.md:12:1: [MD022] Headings should be surrounded by blank lines [*]
README.md:24:5: [MD037] Spaces inside emphasis markers: "* incorrect *" [*]
README.md:31:76: [MD013] Line length exceeds 80 characters
README.md:42:3: [MD010] Hard tabs found, use spaces instead [*]

When running with --fix, rumdl shows which issues were fixed:

README.md:12:1: [MD022] Headings should be surrounded by blank lines [fixed]
README.md:24:5: [MD037] Spaces inside emphasis markers: "* incorrect *" [fixed]
README.md:42:3: [MD010] Hard tabs found, use spaces instead [fixed]

Fixed 3 issues in 1 file

For a more detailed view, use the --verbose option:

✓ No issues found in CONTRIBUTING.md
README.md:12:1: [MD022] Headings should be surrounded by blank lines [*]
README.md:24:5: [MD037] Spaces inside emphasis markers: "* incorrect *" [*]
README.md:42:3: [MD010] Hard tabs found, use spaces instead [*]

Found 3 issues in 1 file (2 files checked)
Run with `--fix` to automatically fix issues

Output Format

rumdl uses a consistent output format for all issues:

{file}:{line}:{column}: [{rule*id}] {message} [{fix*indicator}]

The output is colorized by default:

• Filenames appear in blue and underlined
• Line and column numbers appear in cyan
• Rule IDs appear in yellow
• Error messages appear in white
• Fixable issues are marked with [*] in green
• Fixed issues are marked with [fixed] in green

Development

Prerequisites

• Rust 1.70 or higher
• Make (for development commands)

Building

make build

Testing

make test

License

MIT License