How to list files in Main directory & its Sub directory in dynamically in php?

$directory = substr(DIR_BASE,0,-1);
$it = new RecursiveIteratorIterator(new RecursiveDirectoryIterator($directory));
$i=1;
while($it->valid()) {
 if (!$it->isDot()) {
    echo "$i\n";
    echo 'SubPathName: ' . $it->getSubPathName() . "\n";
    echo 'SubPath:     ' . $it->getSubPath() . "\n";
    echo 'Key:         ' . $it->key() . "\n\n";
    $i++;
 }
 $it->next();
}

How to create Zip file using php?

$zip = new ZipArchive();
$zip_name = time().".zip"; // Zip name
$zip->open($zip_name, ZipArchive::CREATE);
$zip->addFile('test.php');
$zip->close();
header('Content-type: application/zip');
header('Content-Disposition: attachment; filename="'.$zip_name.'"');
readfile($zip_name);
unlink($zip_name);

How to export My Sql Database Backup in php?

$backuptime = "DB_Backup_".DB_NAME."-".time().".sql";
//$backuptime = DB_NAME.".sql";
$data["db_file_name"] = $backuptime;
$insert = $CommonObj->insert_query("db_backup",$data);
$str = "";
$show_tables = "show tables from ".DB_NAME;
$tables = $db->query($show_tables);
if($tables){
   while($row = mysql_fetch_assoc($tables)){
      $table = $row["Tables_in_".DB_NAME];
      $show_each_tables = "show create table ".$table;
      $each_tables  =  $db->query($show_each_tables);
      $each_tables = mysql_fetch_assoc($each_tables);
      $str .= $each_tables["Create Table"];
      $str .= ";\n\n";
      $show_column = "SHOW COLUMNS FROM $table";
      $column  =  $db->query($show_column);
      $get_val_query = "select * from $table";
      $get_val  =  $db->query($get_val_query);
      if($column && mysql_num_rows($get_val)>0){
         $str .= "INSERT INTO `$table` (";
         while($cols = mysql_fetch_assoc($column)){
            $str .= '`'.$cols["Field"].'`, ';
         }
         $str = substr($str,0,-2);
         $str .=  ") VALUES \n";
      }
      if($get_val && mysql_num_rows($get_val)>0){
         while($vals = mysql_fetch_assoc($get_val)){
            $str .= "( ";
            foreach($vals as $k=>$v){
               $v= mysql_real_escape_string($v);
               $str  .= '"'.$v.'", ';
            }
            $str = substr($str,0,-2);
            $str .= "),\n";
         }
         $str = substr($str,0,-2);
      }
      $str .= ";\n\n";
   }
}
$handle = fopen(DIR_DB.$backuptime,'w+');
fwrite($handle,$str);
fclose($handle);