PHP-处理完成后重定向PHP

Question

I was wondering if it's possible to redirect a specific session after a background PHP script was done.

header("location: index.php");

 $myboxes = $_POST['myCheckbox'];

 error_log("location:index.php");

 if(empty($myboxes))
 {
    error_log("You didn't select any boxes.");
  }
  else
  {
    $i = count($myboxes);
   error_log("You selected $i box(es): ");
    for($j = 0; $j < $i; $j++)
    {
      error_log($myboxes[$j] . " ");
    }
    header("location: sucess.php");
  }

Is it possible to redirect/refresh someone after i already redirect him (and waiting for the background process to finish running).

Many Thanks

Answer 1

My advice would be to run the script on index.php and then you can either display text or do a single redirect from there.

To answer your question directly, no it is not possible to send the headers twice. If you do no explicitly tell php to send the initial header it will wait till execution has finished and send the latest header, for example:

header("Location: initialPage.php");
sleep(2);
header("Location: secondPage.php");

Will wait 2 seconds and then redirect the user to 'secondPage.php'

Alternatively you could force php to send the headers by flushing the output like so:

header("Location: initialPage.php");

flush();
ob_flush();

sleep(2);

header("Location: secondPage.php");

Then the user will be redirected to initialPage.php straight away and it will ignore the second redirect

Conclusion: No you cannot get the effect you desire by sending 2 headers.