Markdown Preview Tool

A command-line tool written in Go that converts Markdown files to HTML and automatically previews them in your default web browser.

Features

• Convert Markdown files to clean, sanitized HTML
• Automatic preview in your default web browser
• Cross-platform support (Linux, Windows, macOS)
• Safe HTML generation using bluemonday sanitizer
• Auto-preview mode with file watching capability
• Command-line flags for flexible usage

Installation

# Clone the repository
git clone https://github.com/user/program.git

# Navigate to the project directory
cd program

# Build the binary
go build -o mdp

Dependencies

The program uses the following external packages:

• github.com/microcosm-cc/bluemonday - For HTML sanitization
• github.com/russross/blackfriday/v2 - For Markdown to HTML conversion

Testing

To run the tests:

go test -v

Usage

Basic Usage

# Preview a markdown file
./mdp -file=your_markdown_file.md

# Preview without opening browser (just generate HTML)
./mdp -file=your_markdown_file.md -s

Command-line Flags

• -file: Specify the input Markdown file (required)
• -s: Skip auto-preview in browser
• -t: Specify an alternate HTML template file

Template Customization

The tool supports custom HTML templates for rendering the markdown content. Two template files are provided:

• template.html.tmpl: Basic HTML template
• template-fmt.html.tmpl: Template with custom styling (blue headers)

To use a custom template:

./mdp -file=your_markdown_file.md -t=template-fmt.html.tmpl

Template variables available:

• {{ .Title }}: The title of the document
• {{ .Body }}: The converted HTML content

Auto-Preview Mode

The tool includes an auto-preview feature that watches for changes in your Markdown file and automatically updates the preview. To use this feature:

1. Make the auto-preview script executable:

   chmod +x autopreview.sh

2. Run the auto-preview script with your markdown file:

   ./autopreview.sh your_markdown_file.md

The script will check for changes every 5 seconds and update the preview automatically.

How it Works

1. The program reads the input Markdown file
2. Converts the Markdown to HTML using blackfriday
3. Sanitizes the HTML output using bluemonday for security
4. Creates a temporary HTML file with proper HTML structure
5. Opens the generated HTML in your default web browser (unless -s flag is used)
6. Cleans up the temporary file after preview

The generated HTML includes proper DOCTYPE and HTML structure for optimal rendering.

Running with Python HTTP Server

You can also use Python's built-in HTTP server to view the generated HTML files:

1. Generate the HTML file:

   ./mdp -file=your_markdown_file.md -s

2. Start Python's HTTP server:

   python3 -m http.server 8000

3. Open your browser and navigate to:

   http://localhost:8000/mdpPreview.html
   

This is particularly useful when you want to serve the preview over a network or need to refresh the page manually.