File is tempered or not in the server storage can be checked compared to the uploading time and file modification time

php_file_tempering_check.php

<?php
$Msg = "";
$row = $this->db->query("SELECT folder_name, file_name, uploaded_time FROM documents")->row();
$folder_name = $row->folder_name;
$filename = $row->file_name;
$uploaded_time = $row->uploaded_time;

$file_path = getcwd().DIRECTORY_SEPARATOR.$folder_name.'/'.$filename;

if (file_exists($file_path)) {
    $file_modification_time = date("Y-m-d H:i:s", filemtime("$file_path"));
    if(strtotime($file_modification_time) != strtotime($uploaded_time))
        $Msg = "FIle Tempered";
    else
        $Msg = "File Missing";
}
?>