HASH32 Engineering

Ruby one-liner server

November 26, 2018 | 4 Minute Read

To quickly serve static files in a local development machine, we have used the handy python one-liner to run SimpleHTTPServer. There is a ruby equivalent to it.

Serve static files

I use this usual goto command, which runs python.

python -m SimpleHTTPServer

There is an equivalent ruby one-liner, which runs WEBrick.

ruby -run -e httpd

This is a pretty powerful server. WEBRick can run a small site/blog without much issues. Read about Richard Schneeman’s experiences here.

Breaking it down

Running ruby --help gives the various command line options. The ones in use here are:

-e 'command'    one line of script. Several -e's allowed.
-rlibrary       require the library before executing your script

By some clever file naming by the ruby devs, there is a library in the ruby source named un.rb(view source).

This allows to run common unix commands, as this file defines ruby functions for them. For example the following:

ruby -run -e cp -- [OPTION] SOURCE DEST
ruby -run -e touch -- [OPTION] FILE
ruby -run -e mkdir -- [OPTION] DIRS

It also has an httpd function which runs WEBRick! And it has a list of options as well! You can even configure a ssl certificate if required!

ruby -run -e httpd -- [OPTION] DocumentRoot

--bind-address=ADDR         address to bind
--port=NUM                  listening port number
--max-clients=MAX           max number of simultaneous clients
--temp-dir=DIR              temporary directory
--do-not-reverse-lookup     disable reverse lookup
--request-timeout=SECOND    request timeout in seconds
--http-version=VERSION      HTTP version
--server-name=NAME          name of the server host
--server-software=NAME      name and version of the server
--ssl-certificate=CERT      The SSL certificate file for the server
--ssl-private-key=KEY       The SSL private key file for the server certificate
-v                          verbose

If you want to modify other options, that WEBrick provides, you can customize as required with a .rb script. Here I’m adding a new mime type to the WEBrick server.

require 'webrick'

mime_types = WEBrick::HTTPUtils::DefaultMimeTypes
mime_types.store 'wasm', 'application/wasm'

root = File.expand_path('.')

server = WEBrick::HTTPServer.new(
  Port: 8000,
  DocumentRoot: root,
  MimeTypes: mime_types

trap('INT') { server.shutdown } # Ctrl-C to stop


There are plenty of options. Hack away with WEBrick!

Subscribe to our Newsletter

Get stories like the directly to your inbox once every two weeks.
Tips and tricks, news about tech tools, recent blog entries and exclusive email only stories.