Req #23222 [Opn->Wfx]: Allow controlling header flushing with output buffering
| From: | mike@php.net | Date: | Thu, 01 Aug 2013 12:26:03 +0000 |
| Subject: | Req #23222 [Opn->Wfx]: Allow controlling header flushing with output buffering | ||
| References: | 1 | Groups: | php.bugs |
| Request: | Send a blank email to php-bugs+get-180647@lists.php.net to get a copy of this message | ||
Edit report at https://bugs.php.net/bug.php?id=23222&edit=1
ID: 23222
Updated by: mike@php.net
Reported by: nospam at 1111-internet dot com
Summary: Allow controlling header flushing with output
buffering
-Status: Open
+Status: Wont fix
Type: Feature/Change Request
Package: Zlib related
Operating System: *
PHP Version: *
-Assigned To:
+Assigned To: mike
Block user comment: N
Private report: N
Previous Comments:
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[2003-04-15 20:10:25] iliaa@php.net
As previously indicated by edink@php.net this is not a bug, but rather a feature resultant from
automatic output buffering when compression is enabled. Therefor the bug status is being changed
accordingly.
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[2003-04-15 09:28:31] nospam at 1111-internet dot com
I could see how that could be considered a "feature" to some, but for the reasons
I've already stated I see it only as an unwanted and undesirable side effect.
I request that another feature be added that allows one to override this default behavior, i.e.:
zlib.output_compression = On
zlib.header_flush = On
which would cause the output buffer to flush immediately before each header() is executed.
Thanks...
------------------------------------------------------------------------
[2003-04-15 06:05:24] edink@php.net
This is not a bug, but a feature of PHP's output buffering. Whenever you have any sort of
output buffering enabled header() function will work until the buffers are flushed to the output.
------------------------------------------------------------------------
[2003-04-15 03:13:47] nospam at 1111-internet dot com
Consider the following code:
<?php
echo str_repeat("x", 4095);
header("Location: /somewhere_else.php");
exit;
?>
If zlib.output_compression is off, this will cause 4095 "x"s to display, properly followed
by an error on the header line.
If zlib.output_compression is on, however, the echo line will execute - but nothing is output
immediately because it fails to fill the compression buffer - so the header line goes ahead and
executes and redirects successfully, completely spurning the output.
Granted, nobody would use this particular example in a real world application - I just set it up to
illustrate the problem. I have run into real situations, though, where I'm doing diagnostics or
inadvertently cause an error on code lines that logically precede a header("Location:... call.
This problem prevents my diagnistic or error messages from showing up. Consider:
<?php
// set up mysql connection and
mysql_query("insert into mytable (myfield) values (". $_GET["myvalue"].
")");
// no problem if $_GET["myvalue"] is a number,
// but if it's a non-numeric string like "abc" that line will generate an error
message
// which I would like to see so I can fix the problem...
// but the error message doesn't fill the compression buffer
// so the following redirect happens and usurps the error message
header("Location: /somewhere_else.php");
exit;
// so I go on as though there was never a problem
// until I look at my still-empty database table some time later...
?>
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Edit this bug report at https://bugs.php.net/bug.php?id=23222&edit=1