PHP Header issue with ob

I get header problem while I use ob_start() in the beginning of a page and ob_end_flush() at the end. Because I use header function after some query execution.

 ob_start();
 include_once("header.php");
 global $db;

 $countstmt="SELECT COUNT(*) FROM tbl_lib_hours dh WHERE book_id IN(SELECT book_id FROM tbl_book WHERE user_id=".$_SESSION['uid'].") ";       
 $delHourExist=$db->query($countstmt);  
 if($delHourExist){
      header("location:edit_delivery_hours.php");
 }
 ....
include_once('footer.php');
ob_end_flush();

In header.php there I also added ob_start(); and in footer.php i added ob_end_flush(); , but I think that is not problem, although other pages are running with same script I write above

The error I am getting:

Warning: Cannot modify header information - headers already sent in D:xampphtdocsprojectadd_book_hours.php on line 9

---

I'm a bit baffled the warning message doesn't include the location of the code that caused the first content to be sent to the client. The function headers_sent() can return that location, too. So, for debugging purposes, please try

if($delHourExist)
{
  if ( headers_sent($path, $lineno) ) {
    echo '<pre>Debug: output started at ', $path, ':', $lineno, "</pre>n";
  }
  header("location: edit_delivery_hours.php");
}

---

Is there any space before the first <?php ?

Is there an UTF8-BOM at the beginning of the file?

---

There's a lot of invisible output in your code:

<?php ob_start();?> --- THERE IS A LINE RETURN HERE ---
--- SPACES OR TABS ---<?php include_once("header.php"); ?> --- LINE RETURN ---
--- AND HERE ---<?php global $db;
     ...

Quit starting and ending your php tags. Just do this:

<?php 
    ob_start();
    include_once("header.php");
    global $db;
    ...

Make absolutely sure that there is no output, and no whitespace outside of your tags before the call to ob_start(). If your error is on line 9, you've got a bunch of lines before that call that could be the problem. You may want to post all of those lines, numbered, so we can look at them carefully.

链接地址: http://www.djcxy.com/p/34682.html

上一篇: “头已发送”错误取决于输出长度？

下一篇: 使用ob的PHP头部问题