jordanorelli · August 28, 2013 20:38
diff --git a/gistfile1.go b/gistfile1.go

 package main

 import (
  "flag"
 	"fmt"
 	"io"
 	"log"
 	"net/http"
 	"os"
 	"path/filepath"
 )

 var default_index = `
 <!DOCTYPE html>
 <title>upload</title>
 <meta charset='utf-8'>
 <form action='.' method='post' enctype='multipart/form-data'>
    <input type='file' name='lorem'>
    <input type='file' name='ipsum'>
    <input type='file' name='file'>
    <input type='submit'>
 </form>
 `
 var (
 	index_page = flag.String("index", default_index,
 		"HTML file containing the upload form; if not specified, a simple default page will be used")

 	dest_dir = flag.String("dest", ".",
 		"destination directory for storing uploaded files")
 )

 type makeHandler func(http.ResponseWriter, *http.Request) error

 type handlerError struct {
 	code    int
 	message string
 }

 func (h handlerError) Error() string {
 	return h.message
 }

 func index(w http.ResponseWriter, r *http.Request) error {
 	switch r.Method {
 	case "POST":
 		src_file_reader, err := r.MultipartReader()
 		if err != nil {
 			return fmt.Errorf("unable to open multipartreader: %v", err)
 		}
 		for part, err := src_file_reader.NextPart(); err == nil; {
 			form_name := part.FormName()
 			if form_name != "file" {
 				log.Printf("Skipping '%s'\n", form_name)
 				return handlerError{302, "bad form name"}
 			}
 			log.Printf("Handling '%s'\n", form_name)
 			dest_file, err := os.Create(filepath.Join(*dest_dir, part.FileName()))
 			if err != nil {
 				return fmt.Errorf("unable to create destination file: %v", err)
 			}
 			defer dest_file.Close()
 			if _, err := io.Copy(dest_file, part); err != nil {
 				return handlerError{500, "unable to copy file"}
 			}
 		}
 	case "GET":
 		fmt.Fprintf(w, "%s", *index_page)
 	default:
 		return handlerError{405, "unsupported http method"}
 	}
 	return nil
 }

 func (fn makeHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	err := fn(w, r)
 	if err == nil {
 		return
 	}
 	switch e := err.(type) {
 	case handlerError:
 		if e.code >= 300 && e.code < 400 {
 			http.Redirect(w, r, "/", e.code)
 			break
 		}
 		w.WriteHeader(e.code)
 		io.WriteString(w, e.message)
 	default:
 		http.Redirect(w, r, "/", 302)
 	}
 }

 func main() {
 	flag.Parse()

 	http.Handle("/", makeHandler(index))

 	log.Fatal(http.ListenAndServe("0.0.0.0:4000", nil))

 }

	package main

	import (
	"flag"
	"fmt"
	"io"
	"log"
	"net/http"
	"os"
	"path/filepath"
	)

	var default_index = `
	<!DOCTYPE html>
	<title>upload</title>
	<meta charset='utf-8'>
	<form action='.' method='post' enctype='multipart/form-data'>
	<input type='file' name='lorem'>
	<input type='file' name='ipsum'>
	<input type='file' name='file'>
	<input type='submit'>
	</form>
	`
	var (
	index_page = flag.String("index", default_index,
	"HTML file containing the upload form; if not specified, a simple default page will be used")

	dest_dir = flag.String("dest", ".",
	"destination directory for storing uploaded files")
	)

	type makeHandler func(http.ResponseWriter, *http.Request) error

	type handlerError struct {
	code int
	message string
	}

	func (h handlerError) Error() string {
	return h.message
	}

	func index(w http.ResponseWriter, r *http.Request) error {
	switch r.Method {
	case "POST":
	src_file_reader, err := r.MultipartReader()
	if err != nil {
	return fmt.Errorf("unable to open multipartreader: %v", err)
	}
	for part, err := src_file_reader.NextPart(); err == nil; {
	form_name := part.FormName()
	if form_name != "file" {
	log.Printf("Skipping '%s'\n", form_name)
	return handlerError{302, "bad form name"}
	}
	log.Printf("Handling '%s'\n", form_name)
	dest_file, err := os.Create(filepath.Join(*dest_dir, part.FileName()))
	if err != nil {
	return fmt.Errorf("unable to create destination file: %v", err)
	}
	defer dest_file.Close()
	if _, err := io.Copy(dest_file, part); err != nil {
	return handlerError{500, "unable to copy file"}
	}
	}
	case "GET":
	fmt.Fprintf(w, "%s", *index_page)
	default:
	return handlerError{405, "unsupported http method"}
	}
	return nil
	}

	func (fn makeHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
	err := fn(w, r)
	if err == nil {
	return
	}
	switch e := err.(type) {
	case handlerError:
	if e.code >= 300 && e.code < 400 {
	http.Redirect(w, r, "/", e.code)
	break
	}
	w.WriteHeader(e.code)
	io.WriteString(w, e.message)
	default:
	http.Redirect(w, r, "/", 302)
	}
	}

	func main() {
	flag.Parse()

	http.Handle("/", makeHandler(index))

	log.Fatal(http.ListenAndServe("0.0.0.0:4000", nil))

	}