artyom/upload-form.go

## upload-form.go
// TODO describe program
package main

import (
	"fmt"
	"io"
	"io/ioutil"
	"net/http"
	"os"
	"strings"
)

func main() {
	if err := run(); err != nil {
		os.Stderr.WriteString(err.Error() + "\n")
		os.Exit(1)
	}
}

func run() error {
	return http.ListenAndServe("localhost:8080", http.HandlerFunc(handler))
}

func handler(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodPost {
		w.Write([]byte(page))
		return
	}
	file, header, err := r.FormFile("file")
	if err != nil {
		http.Error(w, err.Error(), http.StatusBadRequest)
		return
	}
	fmt.Fprintf(w, "request headers:\n\n")
	for k, v := range r.Header {
		fmt.Fprintf(w, "%s: %s\n", k, strings.Join(v, ", "))
	}
	fmt.Fprintln(w, "\nfile header:")
	fmt.Fprintf(w, "\tFilename: %q\n\tHeader: %v\n\tSize: %d\n",
		header.Filename, header.Header, header.Size)
	n, err := io.Copy(ioutil.Discard, file)
	fmt.Fprintf(w, "\nfile read: %d bytes, error: %v\n", n, err)
}

const page = `<!doctype html>
<head><title>submit form</title><meta charset=utf-8>
<style>body{font-size:x-large;margin:2em auto;max-width:50%}</style>
<body>
<form method=post enctype=multipart/form-data>
<input id=file type=file name=file>
<input type=submit></form>
`
	// TODO describe program
	package main

	import (
	"fmt"
	"io"
	"io/ioutil"
	"net/http"
	"os"
	"strings"
	)

	func main() {
	if err := run(); err != nil {
	os.Stderr.WriteString(err.Error() + "\n")
	os.Exit(1)
	}
	}

	func run() error {
	return http.ListenAndServe("localhost:8080", http.HandlerFunc(handler))
	}

	func handler(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodPost {
	w.Write([]byte(page))
	return
	}
	file, header, err := r.FormFile("file")
	if err != nil {
	http.Error(w, err.Error(), http.StatusBadRequest)
	return
	}
	fmt.Fprintf(w, "request headers:\n\n")
	for k, v := range r.Header {
	fmt.Fprintf(w, "%s: %s\n", k, strings.Join(v, ", "))
	}
	fmt.Fprintln(w, "\nfile header:")
	fmt.Fprintf(w, "\tFilename: %q\n\tHeader: %v\n\tSize: %d\n",
	header.Filename, header.Header, header.Size)
	n, err := io.Copy(ioutil.Discard, file)
	fmt.Fprintf(w, "\nfile read: %d bytes, error: %v\n", n, err)
	}

	const page = `<!doctype html>
	<head><title>submit form</title><meta charset=utf-8>
	<style>body{font-size:x-large;margin:2em auto;max-width:50%}</style>
	<body>
	<form method=post enctype=multipart/form-data>
	<input id=file type=file name=file>
	<input type=submit></form>
	`