file serving though local netowk

fileserver.go

package main

import (
	"log"
	"fmt"
	"os"
	"net"
	"net/http"
)

const defaultPort = 8000

func main() {
	// Use current as default dir source.
        path, err := os.Getwd()
        if err != nil {
                log.Fatal(err)
        }

	if len(os.Args) >= 2 {
		path = os.Args[1]
	}

	ip := getLocIP()
	port := fmt.Sprintf(":%d", defaultPort)
	log.Printf("serving %s on %s%s", path, ip, port)
	log.Fatal(http.ListenAndServe(port, http.FileServer(http.Dir(path))))
}

func getLocIP() net.IP {
	ifaces, _ := net.Interfaces()
	// handle err
	for _, i := range ifaces {
	    addrs, _ := i.Addrs()
	    // handle err
	    for _, addr := range addrs {
	        var ip net.IP
	        switch v := addr.(type) {
	        case *net.IPNet:
	                ip = v.IP
	        case *net.IPAddr:
	                ip = v.IP
	        }

		if i.Name == "en0" && ip.To4() != nil {
			log.Println("local interface found", i.Name, ip.To4())
			return ip.To4()
		}
	    }
	}
	
	return nil
}