Sorry if the question's title isn't clear about the objective of this question. I was able to make a respond-only webserver using Bash only; when it gets a curl post request, it returns results no matter what the input. ## The post request

curl -d '{"Name":"Lorem", "age":"34"}' -H "Content-Type: application/json" -X POST http://:8080/ 

## The server's script (server.sh)

#!/bin/bash

while true; do
   echo -e "HTTP/1.1 200 OK\n\n
Title
$(date)" \
  | nc -l -k -p 8080 -q 1;
  nc -l -k -p 8080 -q 1 | cat - | grep -o '{...\+}';
done

In the first time I curl, it returns HTTP/1.1 200 OK\n\n

Title

$(date) correctly, but not the nc -l -k -p 8080 -q 1 | cat - | grep -o '{...\+}';, and curl exits. In the second time using curl, it doesn't return HTTP/1.1 200 OK\n\n

Title

$(date) and now returns the result of nc -l -k -p 8080 -q 1 | cat - | grep -o '{...\+}'; and curl doesn't exit. The idea is to process the input from curl (using nc -l -k -p 8080 -q 1 | cat - | grep -o '{...\+}'; + jq) but also to respond and then close curl/the connection.