418: I'm a teapot

Question

As we all should know, there's a HTTP status code 418: I'm a teapot.

Your mission, should you choose to accept it, is to use your creativitea and write the smallest possible server that responds with the above status code to any and every HTTP request made to it.

Standard loopholes apply, including

Fetching the desired output from an external source

This includes doing an HTTP request to fetch the page with the question and extracting a solution from that page. This was mildly amusing back in 2011, but now is derivative and uninteresting.

Meaning you cannot simply redirect the request to another server to have it return the response.

---

Addressing some confusion about server functionality:
Your server can do anything (or nothing) while no HTTP request is made to it as long as it replies with the correct response once a HTTP request is made.

Answer 1

GNU Awk: 69 characters

A server itself (endlessly serves one request at a time), no library used.

Send 418 to everybody who connects (82 69 characters):

BEGIN{while(s="/inet/tcp/80/0/0"){print"HTTP/1.1 418\n"|&s
close(s)}}

Send 418 to everybody who sends something (93 80 characters):

BEGIN{while(s="/inet/tcp/80/0/0"){s|&getline
print"HTTP/1.1 418\n"|&s
close(s)}}

Send 418 to everybody who sends a valid HTTP GET request (122 109 characters):

BEGIN{while(s="/inet/tcp/80/0/0"){s|&getline
if(/^GET \S+ HTTP\/1\.[01]$/)print"HTTP/1.1 418\n"|&s
close(s)}}

Answer 2

Bash (33)

nc -lp80 -q1<<<"HTTP/1.1 418
";$0

Answer 3

PHP - 85 bytes

<?for($s=socket_create_listen(80);socket_write(socket_accept($s),"HTTP/1.1 418
"););

Saved with Windows-Style (CR-LF) line endings, requires php_sockets enabled.

I actually used this as my error code for the Hard Code Golf: Create a Chatroom challenge, but no one noticed.

---

Browser-Friendly version

<?for(socket_getsockname($s=socket_create_listen(80),$n);$t="I'm a teapot";socket_write($c=socket_accept($s),"HTTP/1.0 418 $t
Content-Length: $l

<title>418 $t</title><h1>$t</h1>The requested resource is not suitable for brewing coffee.<hr><i>$n:80</i>"))$l=124+strlen($n);

Start the script in the CLI, and point your browser at http://localhost.

Answer 4

Node.js (LiveScript)

http module - 66

require(\http)createServer (->&1.writeHead 418;&1.end!) .listen 80

Inspired by Qwertiy's answer.

net module - 76

require(\net)createServer (->it.write 'HTTP/1.1 418\r\n';it.end!) .listen 80

Answer 5

Ruby + Rack, 19 bytes

run->e{[418,{},[]]}

Must be saved as config.ru, and run with the rackup command.

Or if you prefer "pure" Ruby:

Rack::Handler::WEBrick.run->e{[418,{},[]]}

42 bytes + -rrack flag = 48 bytes

Answer 6

Bash+BSD general commands, 29

Borrowing back a little bit from other answers:

nc -lp80<<<"HTTP/1.1 418
";$0

Works for me with wget.

First answer to use nc, 38

for((;;)){
nc -l 80 <<<HTTP/1.1\ 418
}

I'm assuming root privileges - run as follows:

sudo bash ./418.sh

Answer 7

Ruby (nc system command) - 35

loop{`nc -l 80 <<<"HTTP/1.1 418"`}

DigitalTrauma should get the credit for the idea of using nc, however Ruby can make an infinite loop with fewer characters than Bash :)

Ruby (TCPServer) - 75

require'socket'
s=TCPServer.new 80
loop{(s.accept<<'HTTP/1.1 418
').close}

That newline is intentional -- the actual newline character is one character shorter than "\n".

Ruby (WEBrick HTTPServer) - 87

require'webrick'
(s=WEBrick::HTTPServer.new).mount_proc(?/){|_,r|r.status=418}
s.start

Answer 8

Python 3 106

s=__import__('socket').socket(2,1) 
s.bind(('',80))
s.listen(9)
while 1:s.accept()[0].send('HTTP/1.1 418\n')

Answer 9

Node.js, 80

require('http').createServer(function(q,s){s.writeHead(418);s.end()}).listen(80)

The response is

HTTP/1.1 418 I'm a teapot
Date: Wed, 19 Nov 2014 21:08:27 GMT
Connection: keep-alive
Transfer-Encoding: chunked

0

Answer 10

Haskell - 142 bytes

import Network
import System.IO
main=listenOn(PortNumber 8888)>>=f
f s=do{(h,_,_)<-accept s;hPutStr h"HTTP/1.1 418\r\n";hFlush h;hClose h;f s}

Answer 11

Tcl (>= 8.5), 78 bytes

Edit - added in an extra newline (total of 2 newlines) for the sake of compliance.

socket -server {apply {{c - -} {puts $c "HTTP/1.1 418
";close $c}}} 80
vwait f

Answer 12

Powershell, 398

$Listener = New-Object System.Net.Sockets.TcpListener([System.Net.IPAddress]::Parse("10.10.10.10"), 80)
$Listener.Start()
while($true)
{
    $RemoteClient = $Listener.AcceptTcpClient()
    $Stream = $RemoteClient.GetStream()
    $Writer = New-Object System.IO.StreamWriter $Stream
    $Writer.Write("HTTP/1.1 418 I'm a Teapot`nConnection: Close`n`n")
    $Writer.Flush()
    $RemoteClient.Close()
}

258

$l=New-Object System.Net.Sockets.TcpListener([System.Net.IPAddress]::Parse("10.10.10.10"),80);$l.Start();while($true){$r = $l.AcceptTcpClient();$s = $r.GetStream();$w = New-Object System.IO.StreamWriter $s;$w.Write("HTTP/1.1 418`n`n");$w.Flush();$r.Close()}

Answer 13

Julia: 86 73 characters

s=listen(80)
while 1<2
c=accept(s)
write(c,"HTTP/1.1 418

")
close(c)
end

Answer 14

R, 80 characters

Never did socket programming with R before, but I'll give it a try:

repeat{s=socketConnection(,80,T,open="r+");cat("HTTP/1.1 418\n",file=s);close(s)}

Here socketConnection opens a socket: first argument should be the host, the default being localhost we can skip it here; the second argument is the port which has no default, then argument server when specified TRUE creates the socket, if FALSE it just connects to an existing one. T is, by default, equals to TRUE, in R.

Edit: As suggested in a suggested edit by @AlexBrown, this could be shorten into 69 characters:

repeat cat("HTTP/1.1 418\n",file=s<-socketConnection(,80,T))+close(s)

Answer 15

Node.js koa, 61 Bytes

require('koa')().use(function*(){this.status=418}).listen(80)

Response:

HTTP/1.1 418 I'm a teapot
X-Powered-By: koa
Content-Type: text/plain; charset=utf-8
Content-Length: 12
Date: Thu, 20 Nov 2014 07:20:36 GMT
Connection: close

I'm a teapot

Requires node v0.11.12 +

Run as:

node --harmony app.js

Answer 16

Shell + socat, 60

socat tcp-l:80,fork exec:'printf HTTP/1.1\\ 418\\ T\r\n\r\n'

Answer 17

You can do this with minimal effort using a .htaccess file and php.

All the accesses to your server will return the status 418.

Below is the code:

.htaccess (28 bytes)

RewriteRule .* index.php [L]

PHP (38 19 bytes)

<<?header(TE,1,418);

---

Thanks to @primo for saving me a bunch of bytes!

---

I have tested this and confirm it returns the desired result!

By the way, "Pedido" means "Request" and "Resposta" means "Answer".

Answer 18

MATLAB, 97 86 bytes

Not really a serious contender in terms of absolute byte-count, but I'd like to post it because I didn't think it would be possible to write a fully functional webserver using a mathematical tool. Note the use of property shortening: 'Ne','s' internally expands to 'NetworkRole', 'server'.

t=tcpip('0.0.0.0','Ne','s');while 1
fopen(t)
fprintf(t,'HTTP/1.1 418\n')
fclose(t)
end

Answer 19

node.js with CoffeeScript (76)

require("connect")().use((q,s,n)->s.writeHead 418;s.end();return;).listen 80

Just compile it to JavaScript, then you need to run npm install connect. After that start it with node server.js

Answer 20

nginx - 35

events{}http{server{return 418;}}

Throw that in nginx.conf, start nginx.

Not sure if this uses standard loopholes "Using built-in functions to do the work" or "Interpreting the challenge too literally." Oops, looks like OP won't like this answer.

Answer 21

Perl, 78

use Web::Simple;sub dispatch_request{sub{[418,[],[]]}}__PACKAGE__->to_psgi_app

run as plackup whatever.pl.

Answer 22

Python 2.7/Django, 94 bytes

(added from default boilerplate from django-admin.py startproject) In urls.py:

import django.http.HttpResponse as r;urlpatterns=patterns(url(r'^*$',lambda q:r(status=418)))

Answer 23

Java 7, 208 bytes

import java.net.*;class R{public static void main(String[]a)throws Exception{for(ServerSocket s=new ServerSocket(80);;){Socket p=s.accept();p.getOutputStream().write("HTTP/1.0 418\n".getBytes());p.close();}}}

This question needed a java answer.

poke@server ~
$ curl -i localhost:80
HTTP/1.0 418

Answer 24

C# + OWIN 251 240

I was really hoping it'd be shorter, but the long namespaces ruined that plan. Requires the Microsoft.Owin.SelfHost package available on NuGet.

using Owin;class P{static void Main(){Microsoft.Owin.Hosting.WebApp.Start<P>("http://localhost");while(0<1);}public void Configuration(IAppBuilder a){a.Run(c=>{c.Response.StatusCode=418;return System.Threading.Tasks.Task.FromResult(0);});}}

Answer 25

node.js with connect (78)

require('connect')().use(function(q,s,n){s.writeHead(418);s.end()}).listen(80)

You need to run npm install connect first. Then start it with node server.js

Answer 26

Go, 162 bytes

package main
import "net/http"
func main(){http.HandleFunc("/",func(w http.ResponseWriter,r *http.Request){w.WriteHeader(418)})
http.ListenAndServe(":80", nil)
}

Answer 27

Factor, 101 141 bytes

[ utf8 <threaded-server> readln 10 base> >>insecure [ "HTTP/1.1 418\r" print flush ] >>handler [ start-server ] in-thread start-server drop ]

Return 418 to everyone who connects.