RedCloth textile convert to HTML

#!/usr/bin/ruby
#
# redcloth2html
# required packages: ruby libredcloth-ruby
#
require 'redcloth'

if (ARGV.size < 2) then
    print "redcloth2html <input> <output>\n"
    print "note: - means stdin or stdout.\n"
    exit 0
end

if ARGV[0] == '-' then
    infilepath = '/dev/stdin'
else
    infilepath = ARGV[0]
end

if ARGV[1] == '-' then
    outfilepath = '/dev/stdout'
else
    outfilepath = ARGV[1]
end

raw = IO.read infilepath

rc = RedCloth.new raw

File.open outfilepath, 'w' do |outf|
    outf.write rc.to_html
end