md_to_html.rb

#!/usr/bin/env ruby
require 'redcarpet'

md_file = File.read(ARGV.first)
html_filename = File.basename(ARGV.first, ".md") + ".html" 

File.open(html_filename, 'w') do |file|
  file.write(Redcarpet::Markdown.new(Redcarpet::Render::HTML.new).render(md_file))
end

To use this on Slackware, run as root:

gem install redcarpet

Then log out of the root account and run the script as a normal user with:

ruby md_to_html.rb Markdown_file.md

It will save the converted markdown text to an html formatted file within the same directory as the script.

"Markdown_file.md" will output "Markdown_file.html"