file-server: fix ShowList on root dir

Former-commit-id: 6795382235d76942bcfd31ecc0b4ab02ecb85a8a

_examples/file-server/file-server/main.go

@@ -0,0 +1,66 @@
+package main
+
+import (
+	"crypto/md5"
+	"fmt"
+	"io"
+	"mime/multipart"
+	"os"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/kataras/iris/v12"
+)
+
+func init() {
+	os.Mkdir("./uploads", 0700)
+}
+
+func main() {
+	app := iris.New()
+	app.RegisterView(iris.HTML("./views", ".html"))
+
+	app.Get("/", index)
+
+	app.Get("/upload", uploadView)
+	app.Post("/upload", upload)
+
+	app.HandleDir("/files", "./uploads", iris.DirOptions{
+		Gzip:     true,
+		ShowList: true,
+	})
+
+	app.Listen(":8080")
+}
+
+func index(ctx iris.Context) {
+	ctx.Redirect("/upload")
+}
+
+func uploadView(ctx iris.Context) {
+	now := time.Now().Unix()
+	h := md5.New()
+	io.WriteString(h, strconv.FormatInt(now, 10))
+	token := fmt.Sprintf("%x", h.Sum(nil))
+
+	ctx.View("upload.html", token)
+}
+
+func upload(ctx iris.Context) {
+	_, err := ctx.UploadFormFiles("./uploads", beforeSave)
+	if err != nil {
+		ctx.StopWithError(iris.StatusInternalServerError, err)
+		return
+	}
+
+	ctx.Redirect("/files")
+}
+
+func beforeSave(ctx iris.Context, file *multipart.FileHeader) {
+	ip := ctx.RemoteAddr()
+	ip = strings.ReplaceAll(ip, ".", "_")
+	ip = strings.ReplaceAll(ip, ":", "_")
+
+	file.Filename = ip + "-" + file.Filename
+}