Index: src/fs.cr
==================================================================
--- src/fs.cr
+++ src/fs.cr
@@ -3,10 +3,11 @@
 require "uri"
 require "http"
 require "option_parser"
 require "yaml"
 require "logger"
+require "mime"
 
 # Class for reading configuration information from fs.yml.
 
 class Config
   # Required settings
@@ -93,10 +94,13 @@
     @config = config
     @root = config.root
     @server = uninitialized HTTP::Server
   end
 
+  # This gets called if HTTP::StaticFileHandler can't find a file.
+  # The most common case is a directory path, in which case
+  # we look for index.html in that directory.
   def process_request(context : HTTP::Server::Context)
     request = context.request
     request_path = request.path
     method = request.method
 
@@ -105,11 +109,11 @@
     path = File.join(@root, request_path)
     if Dir.exists?(path)
       path = File.join(path, "index.html")
     end
     if File.exists?(path)
-      content_type = `file -b --mime-type #{path}`.strip
+      content_type = MIME.from_filename(path)
       context.response.content_type = content_type
       MyLog.info "Serving #{path}, content type #{content_type}"
       File.open(path) { |file| IO.copy(file, context.response) }
     else
       MyLog.error "No such file #{path}"