server.py

#!/usr/bin/env python

from dataclasses import dataclass
from http.server import HTTPServer, BaseHTTPRequestHandler

H = {}

@dataclass
class Path:
    method: str = None
    key: str = None
    value: str = None
    
class S(BaseHTTPRequestHandler):
    def parsePath(self, path):
        path = path.strip("/")
        parsedPath = Path()
        if path.startswith("get?key="):
            parsedPath.method = "get"
            path = path.removeprefix("get?key=")
            value = H.get(path, "null")
            parsedPath.key = path
            parsedPath.value = value
            return parsedPath

        elif path.startswith("set?"):
            parsedPath.method = "set"
            path = path.removeprefix("set?")
            key, value = path.split("=",1)
            H[key] = value
            parsedPath.key = key
            parsedPath.value = value
            return parsedPath
        else:
            return None

    def do_GET(self):
        self.send_response(200)
        self.send_header("Content-type", "text/html")
        self.end_headers()
        parsedPath = self.parsePath(self.path)
        if parsedPath.method == "get":
            self.wfile.write((parsedPath.value+"\n").encode("utf8"))
        return 

if __name__ == "__main__":
    addr = "localhost"
    port = 4000
    httpd = HTTPServer((addr, port), S)
    httpd.serve_forever()

server.sh

#!/usr/bin/env bash

#ncat -e ./server.sh -kl 4000

#set -x
mkdir -p /tmp/cache

IFS=$' \t\n\r'

declare -A H

read -r request path _
if [ "$request" != "GET" ]; then
    printf 'HTTP/1.1 404 Not Found\r\n\r\n'
    exit
fi

IFS='/?='
read -r _ method key value < <(printf '%s\n' "$path")
unset IFS

printf 'HTTP/1.1 200 OK\r\n\r\n'
case $method in
    "get")
        #echo ${H["$value"]:-"null"}
        cat /tmp/cache/$value 2>/dev/null || echo null
     ;;

    "set")
        #H[$key]="$value"
        echo $value >/tmp/cache/$key
     ;;
esac
#echo $method, $key, $value
exit