How to insert very big data in PHP with user interface change

I'm trying to do that in PHP.

This code should insert 500000 rows in users table and after each row should print the value of $C(last for loop counter) in new line but it doesn't work properly. It inserts rows correctly but it doesn't print $c after inserting the row. Why doesn't it work like that? And how can i update this code to work like i want?

Thanks all in advance

 <?php
   $handler = new PDO("mysql:host=localhost;dbname=test",'root','');
   $handler->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
   function randomname(){
     $len = mt_rand(20,50);
     $string = "";
     for($i=0;$i<$len;$i++){
       $ch = mt_rand(32, 122);
        if(($ch == 32 && $string != "") || ($ch >=97 && $ch <=122))
          $string .= chr($ch);
        else
          continue;
      }
      return $string;
   }

   function randomemail(){
     $len = mt_rand(7,15);
     $string = "";
    for($i=0;$i<$len;$i++){
         $ch = mt_rand(32, 122);
       if(($ch == 32 && $string != "") || ($ch >=97 && $ch <=122))
          $string .= chr($ch);
       else
         continue;
     }
     if($len < 10)
       return $string."@hotmail.com";
     else
       return $string."@gmail.com";
    }

    ini_set('max_execution_time', 500000);

   for($c = 0; $c<=500000;$c++){
     $name = randomname();
     $mail = randomemail();
      $query = $handler->query("insert into users(name, mail, password, created_at) values('$name', '$mail', '123132', now())");
      echo "$c</br>";
    }