PHP, Cannot Add Header Information Error

Cannot Add Header Information Error

Author	Message
Van DeWal #1 / 4	Cannot Add Header Information Error I'm using PHP sessions to store the session data in a database, and thus am using the session_set_save_handler function to set up custom handlers. I also set session_cache_limiter('none'). However, upon logging out by calling session_destroy(), I am trying to redirect the output back to the login screen with header("Location: index.php"). However, I receive the following error: Warning: Cannot add header information - headers already sent by (output started at /home/vansvaul/public_html/outreach/sess.php:156) call, but that just suppresses the error message, and the redirect still does not complete. I've tried to use a flush() before the header() call also, to no avail. So, how can I make this redirect work? The headers are being sent by the sess.php file, which includes all of the functions for session_set_save_handler and so forth. Thanks for any help. Regards, Van
Thu, 14 Apr 2005 03:01:41 GMT

Owen Jacobso #2 / 4	Cannot Add Header Information Error Quote: > I'm using PHP sessions to store the session data in a database, and thus am > using the session_set_save_handler function to set up custom handlers. I > also set session_cache_limiter('none'). However, upon logging out by > calling session_destroy(), I am trying to redirect the output back to the > login screen with header("Location: index.php"). However, I receive the > following error: > Warning: Cannot add header information - headers already sent by (output > started at /home/vansvaul/public_html/outreach/sess.php:156) > call, but that just suppresses the error message, and the redirect still > does not complete. I've tried to use a flush() before the header() call > also, to no avail. > So, how can I make this redirect work? The headers are being sent by the > sess.php file, which includes all of the functions for > session_set_save_handler and so forth. Is there a FAQ somewhere that we could add information about 'Cannot add header information'-related information to? If not, should someone write one? (Am volunteering, if so) To answer the question, your script is producing output somewhere before sess.php:156. Once output has been sent to the client, you can't add any more headers (cookie(), header() calls, primarily). Either move whatever bit of code is generating headers, or use output buffering (look up ob_start() et al) to prevent output from being sent until you intentionally flush the buffer.
Fri, 15 Apr 2005 02:55:12 GMT

reggi #3 / 4	Cannot Add Header Information Error Quote: > Is there a FAQ somewhere that we could add information about 'Cannot add > header information'-related information to? If not, should someone write > one? (Am volunteering, if so) Owen, this is a new group (still) and AFAIK there is no current FAQ specific to this group. Someone was sending periodic group stats, but I'd wouldn't mind seeing weekly FAQ messages (similar to comp.lang.perl.misc) It may be in the best interest of the group to start a top-level thread requesting collaboration on the creation of an FAQ site, and potentially a weekly FAQ reminder post. I would help wherever I could. This may help stem the flow of 'why does my script break when I use $foo to access my form variables'. regards, reggie.
Fri, 15 Apr 2005 03:21:46 GMT

Will May #4 / 4	Cannot Add Header Information Error [snip] Quote: > Warning: Cannot add header information - headers already sent by (output > started at /home/vansvaul/public_html/outreach/sess.php:156) Have a look at the file sess.php. Go to line 156, and see what could possibly be outputting anything to the client both _on_ and _around_ this line. It could be a blank line that is not contained in php code, e.g. ########################## <?php blah blah blah; ?> <?php blah ...... ########################## or it could be a rogue echo, print, sprintf, etc. If you can't find the problem, post the source code Quote: function > call, but that just suppresses the error message, and the redirect still > does not complete. I've tried to use a flush() before the header() call > also, to no avail. Flush() is the wrong command to be using here. Flush() will just send anything waiting in the output buffers on it's way to the client. You could always buffer your output with ob_start() -- then the problem is gone (most likely). But finding the cause & fixing it is better than putting in workarounds. Cheers, Will M -- Registered Linux User #273744 <www.volutin.net -- everything irrelevant>
Fri, 15 Apr 2005 19:31:18 GMT

Page 1 of 1

[ 4 post ]