I am using XAMPP on Windows. By printing $_FILES[\"file\"][\"tmp_name\"], it seems that the temporary file was saved at C:\\xampp\\tmp\\phpABCD.tmp. But I cannot se
$_FILES[\"file\"][\"tmp_name\"]
Use move_uploaded_file(file, path), specify the file and the path where you want to store the file.
move_uploaded_file(file, path)
A copy of that file is created and gets stored.