Simple file

fileserver.go

package main

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

func main() {
	http.HandleFunc("/upload", handleUpload)
	log.Fatal(http.ListenAndServe(":8080", nil))
}

func handleUpload(w http.ResponseWriter, r *http.Request) {
	fmt.Printf("%v\n", "file upload")
	r.ParseMultipartForm(32 << 20)
	file, header, err := r.FormFile("file")

	if err != nil {
		fmt.Fprintln(w, err)
		return
	}
	defer file.Close()

	out, err := os.Create("out.bin")
	if err != nil {
		fmt.Fprintf(w, "Failed to open the file for writing")
		return
	}
	defer out.Close()
	_, err = io.Copy(out, file)
	if err != nil {
		fmt.Fprintln(w, err)
	}

	// the header contains useful info, like the original file name
	fmt.Fprintf(w, "File %s uploaded successfully.", header.Filename)
}