# HTTP Server

This program is a simple HTTP server written in Go. It defines two HTTP handlers: `/hello` and `/headers`. When the server receives a request to either of these paths, it will respond accordingly.

Here's a breakdown of the code:

```go
package main

import (
	"fmt"
	"net/http"
)

// hello is an HTTP handler function that responds with "hello\n".
func hello(w http.ResponseWriter, req *http.Request) {
	fmt.Fprintf(w, "hello\n")
}

// headers is an HTTP handler function that responds with the request headers.
func headers(w http.ResponseWriter, req *http.Request) {
	// Iterate over request headers and write them to the response.
	for name, headers := range req.Header {
		for _, h := range headers {
			fmt.Fprintf(w, "%v: %v\n", name, h)
		}
	}
}

func main() {
	// Register the /hello and /headers handlers with the default ServeMux.
	http.HandleFunc("/hello", hello)
	http.HandleFunc("/headers", headers)

	// Start the HTTP server on port 8090.
	http.ListenAndServe(":8090", nil)
}
```

Explanation:

1. `hello` is an HTTP handler function that writes the string "hello\n" to the response writer (`w`).
2. `headers` is an HTTP handler function that iterates over the request headers and writes them to the response writer.
3. In the `main` function:
   * The `/hello` and `/headers` paths are registered with their corresponding handler functions using `http.HandleFunc`.
   * The server is started using `http.ListenAndServe` on port `8090`.

To test the server, you can make requests to `http://localhost:8090/hello` and `http://localhost:8090/headers`. The `/hello` path will respond with "hello\n", and the `/headers` path will respond with the headers of the incoming request.