ob_end_clean(3) [php man page]
OB_END_CLEAN(3) 1 OB_END_CLEAN(3)
ob_end_clean - Clean (erase) the output buffer and turn off output buffering
SYNOPSIS
bool ob_end_clean (void )
DESCRIPTION
This function discards the contents of the topmost output buffer and turns off this output buffering. If you want to further process the
buffer's contents you have to call ob_get_contents(3) before ob_end_clean(3) as the buffer contents are discarded when ob_end_clean(3) is
called.
The output buffer must be started by ob_start(3) with PHP_OUTPUT_HANDLER_CLEANABLE and PHP_OUTPUT_HANDLER_REMOVABLE flags. Otherwise
ob_end_clean(3) will not work.
RETURN VALUES
Returns TRUE on success or FALSE on failure. Reasons for failure are first that you called the function without an active buffer or that
for some reason a buffer could not be deleted (possible for special buffer).
ERRORS
/EXCEPTIONS
If the function fails it generates an E_NOTICE.
EXAMPLES
The following example shows an easy way to get rid of all output buffers:
Example #1
ob_end_clean(3) example
<?php
ob_start();
echo 'Text that won't get displayed.';
ob_end_clean();
?>
SEE ALSO
ob_start(3), ob_get_contents(3), ob_flush(3).
PHP Documentation Group OB_END_CLEAN(3)
Check Out this Related Man Page
OB_START(3) 1 OB_START(3)
ob_start - Turn on output buffering
SYNOPSIS
bool ob_start NULL PHP_OUTPUT_HANDLER_STDFLAGS ([callable $output_callback], [int $chunk_size], [int $flags])
DESCRIPTION
This function will turn output buffering on. While output buffering is active no output is sent from the script (other than headers),
instead the output is stored in an internal buffer.
The contents of this internal buffer may be copied into a string variable using ob_get_contents(3). To output what is stored in the inter-
nal buffer, use ob_end_flush(3). Alternatively, ob_end_clean(3) will silently discard the buffer contents.
Warning
Some web servers (e.g. Apache) change the working directory of a script when calling the callback function. You can change it back
by e.g. chdir(dirname($_SERVER['SCRIPT_FILENAME'])) in the callback function.
Output buffers are stackable, that is, you may call ob_start(3) while another ob_start(3) is active. Just make sure that you call
ob_end_flush(3) the appropriate number of times. If multiple output callback functions are active, output is being filtered sequentially
through each of them in nesting order.
PARAMETERS
o $output_callback
- An optional $output_callback function may be specified. This function takes a string as a parameter and should return a string.
The function will be called when the output buffer is flushed (sent) or cleaned (with ob_flush(3), ob_clean(3) or similar func-
tion) or when the output buffer is flushed to the browser at the end of the request. When $output_callback is called, it will
receive the contents of the output buffer as its parameter and is expected to return a new output buffer as a result, which will
be sent to the browser. If the $output_callback is not a callable function, this function will return FALSE. This is the callback
signature:
string handler (string $buffer, [int $phase])
o $buffer
- Contents of the output buffer.
o $phase
- Bitmask of PHP_OUTPUT_HANDLER_* constants.
If $output_callback returns FALSE original input is sent to the browser. The $output_callback parameter may be bypassed by passing
a NULL value. ob_end_clean(3), ob_end_flush(3), ob_clean(3), ob_flush(3) and ob_start(3) may not be called from a callback function.
If you call them from callback function, the behavior is undefined. If you would like to delete the contents of a buffer, return ""
(a null string) from callback function. You can't even call functions using the output buffering functions like print_r($expression,
true) or highlight_file($filename, true) from a callback function.
Note
In PHP 4.0.4, ob_gzhandler(3) was introduced to facilitate sending gz-encoded data to web browsers that support compressed
web pages. ob_gzhandler(3) determines what type of content encoding the browser will accept and will return its output
accordingly.
o $chunk_size
- If the optional parameter $chunk_size is passed, the buffer will be flushed after any output call which causes the buffer's
length to equal or exceed $chunk_size. The default value 0 means that the output function will only be called when the output buf-
fer is closed. Prior to PHP 5.4.0, the value 1 was a special case value that set the chunk size to 4096 bytes.
o $flags
- The $flags parameter is a bitmask that controls the operations that can be performed on the output buffer. The default is to
allow output buffers to be cleaned, flushed and removed, which can be set explicitly via PHP_OUTPUT_HANDLER_CLEANABLE | PHP_OUT-
PUT_HANDLER_FLUSHABLE | PHP_OUTPUT_HANDLER_REMOVABLE, or PHP_OUTPUT_HANDLER_STDFLAGS as shorthand. Each flag controls access to a
set of functions, as described below:
+-----------------------------+---------------------------------------------------+
| Constant | |
| | |
| | Functions |
| | |
+-----------------------------+---------------------------------------------------+
| | |
|PHP_OUTPUT_HANDLER_CLEANABLE | |
| | |
| | ob_clean(3), ob_end_clean(3), and |
| | ob_get_clean(3). |
| | |
| | |
|PHP_OUTPUT_HANDLER_FLUSHABLE | |
| | |
| | ob_end_flush(3), ob_flush(3), and |
| | ob_get_flush(3). |
| | |
| | |
|PHP_OUTPUT_HANDLER_REMOVABLE | |
| | |
| | ob_end_clean(3), ob_end_flush(3), and |
| | ob_get_flush(3). |
| | |
+-----------------------------+---------------------------------------------------+
RETURN VALUES
Returns TRUE on success or FALSE on failure.
CHANGELOG
+--------+---------------------------------------------------+
|Version | |
| | |
| | Description |
| | |
+--------+---------------------------------------------------+
| 7.0.0 | |
| | |
| | In case ob_start(3) is used inside an output |
| | buffer callback, this function will no longer |
| | issue an E_ERROR but instead an E_RECOVER- |
| | ABLE_ERROR, allowing custom error handlers to |
| | catch such errors. |
| | |
| 5.4.0 | |
| | |
| | The third parameter of ob_start(3) changed from |
| | a boolean parameter called $erase (which, if set |
| | to FALSE, would prevent the output buffer from |
| | being deleted until the script finished execut- |
| | ing) to an integer parameter called $flags. |
| | Unfortunately, this results in an API compatibil- |
| | ity break for code written prior to PHP 5.4.0 |
| | that uses the third parameter. See the flags |
| | example for an example of how to handle this with |
| | code that needs to be compatible with both. |
| | |
| 5.4.0 | |
| | |
| | A chunk size of 1 now results in chunks of 1 |
| | byte being sent to the output buffer. |
| | |
| 4.3.2 | |
| | |
| | This function was changed to return FALSE in |
| | case the passed $output_callback can not be exe- |
| | cuted. |
| | |
+--------+---------------------------------------------------+
EXAMPLES
Example #1
User defined callback function example
<?php
function callback($buffer)
{
// replace all the apples with oranges
return (str_replace("apples", "oranges", $buffer));
}
ob_start("callback");
?>
<html>
<body>
<p>It's like comparing apples to oranges.</p>
</body>
</html>
<?php
ob_end_flush();
?>
The above example will output:
<html>
<body>
<p>It's like comparing oranges to oranges.</p>
</body>
</html>
Example #2
Creating an uneraseable output buffer in a way compatible with both PHP 5.3 and 5.4
<?php
if (version_compare(PHP_VERSION, '5.4.0', '>=')) {
ob_start(null, 0, PHP_OUTPUT_HANDLER_STDFLAGS ^
PHP_OUTPUT_HANDLER_REMOVABLE);
} else {
ob_start(null, 0, false);
}
?>
SEE ALSO
ob_get_contents(3), ob_end_clean(3), ob_end_flush(3), ob_implicit_flush(3), ob_gzhandler(3), ob_iconv_handler(3), mb_output_handler(3),
ob_tidyhandler(3).
PHP Documentation Group OB_START(3)