properly use createtemp for the uploaded files

handlers.go

@@ -7,7 +7,6 @@ import (
 	"net/http"
 	"os"
 	"path/filepath"
-	"time"
 )
 
 func handleRoot(w http.ResponseWriter, r *http.Request) {
@@ -37,32 +36,31 @@ func handleUpload(w http.ResponseWriter, r *http.Request) {
 	}
 	defer file.Close()
 
-	filename := fmt.Sprintf("%d_%s", time.Now().UnixNano(), header.Filename)
+	tempFile, err := os.CreateTemp(uploadDir, header.Filename)
-	filepath := filepath.Join(uploadDir, filename)
-
-	newFile, err := os.Create(filepath)
 	if err != nil {
 		http.Error(w, err.Error(), http.StatusInternalServerError)
 		return
 	}
-	defer newFile.Close()
+	defer tempFile.Close()
 
-	_, err = io.Copy(newFile, file)
+	_, err = io.Copy(tempFile, file)
 	if err != nil {
 		http.Error(w, err.Error(), http.StatusInternalServerError)
 		return
 	}
 
+	tempFilename := filepath.Base(tempFile.Name())
+
 	go func() {
-		err := processInputFile(filepath)
+		err := processInputFile(tempFile.Name())
 		if err != nil {
 			fmt.Printf("Error processing file: %v\n", err)
 		}
 
-		os.Remove(filepath)
+		os.Remove(tempFile.Name())
 	}()
 
-	http.Redirect(w, r, "/progress?filename="+filename, http.StatusSeeOther)
+	http.Redirect(w, r, "/progress?filename="+tempFilename, http.StatusSeeOther)
 }
 
 func handleProgress(w http.ResponseWriter, r *http.Request) {