Minimal Viable Web Server in Nim

webserver.nim

# Minimal Viable Web Server for Nim 

# 1) Install Nim: 
# https://nim-lang.org/install.html

# 2) To run, enter this in a terminal window:
# nim c -r webserver.nim

# 3) Press Control-C to quit / stop the server.

# Nim creates a small, compiled binary.
# To run again:
# ./webserver

# With thanks to Alasdair Allan (@aallan) for the inspiration:
# https://www.raspberrypi.com/news/how-to-run-a-webserver-on-raspberry-pi-pico-w/

# Tested on macOS Monterey (12.6.6)
# and Termux v0.117, Android 13

import std/net, std/strutils
from std/posix import SIGINT, SIGTERM, onSignal

var
  address = "127.0.0.1"
  port = 8080
  client: Socket
  url = ""

let socket = newSocket()
socket.setSockOpt(OptReusePort, true)
socket.bindAddr(Port(port), address)
socket.listen()

onSignal(SIGINT, SIGTERM):
  echo "⏹️  Stopping..."
  quit()

echo "▶️  Starting server at http://" & address & ":" & $port & "/"
while true:
  socket.acceptAddr(client, address)
  var line: string
  while true:
    client.readLine(line)
    var lineparts = line.split(' ')

    if lineparts[0] == "GET":
      url = lineparts[1]
      echo lineparts[0] & " " & url

    if line == "\r\n":
      if url == "/":
        client.send("HTTP/1.1 200 OK\r\n")
        client.send("Content-type: text/html; charset=utf-8\r\n\r\n")
        client.send("<h1 style='font-size: 50;'>Hello, World! 👋🏽🌐</h1>")
        client.close()
        break
      else:
        client.send("HTTP/1.1 404 Not Found\r\n")
        client.send("Content-type: text/html; charset=utf-8\r\n\r\n")
        client.send("<h1 style='font-size: 200;'>🤷</h1>")
        client.close()
        break