A note on the above example...
with PHP 4 >= 4.2.0, PHP 5 you can use a combination of ob_get_level() and ob_end_flush() to avoid using the @ (error suppresion) which should probably be a little faaster.
<?php
while (ob_get_level() > 0) {
ob_end_flush();
}
?>
ob_end_flush
(PHP 4, PHP 5, PHP 7, PHP 8)
ob_end_flush — 出力用バッファをフラッシュ(送信)し、出力のバッファリングをオフにする
説明
ob_end_flush(): bool
この関数は、出力用バッファの内容を出力し、出力のバッファリングをオフにします。 出力用バッファの内容を更に処理したい場合には、 バッファの内容は ob_end_flush() がコールされた後に消去されるため、 ob_end_flush() の前に ob_get_contents() をコールする必要があります。
出力バッファを開始するときに、 ob_start() で PHP_OUTPUT_HANDLER_FLUSHABLE および PHP_OUTPUT_HANDLER_REMOVABLE フラグを指定する必要があります。指定しなければ、ob_end_flush() は動作しません。
注意: この関数は ob_get_flush() に似ていますが、 ob_get_flush() はバッファを文字列として返すという点が違います。
パラメータ
この関数にはパラメータはありません。
返り値
成功した場合に true を、失敗した場合に false を返します。
失敗する原因は、まず、アクティブなバッファ以外に対してこの
関数をコールしたか、あるいは何らかの理由により
バッファを消去することができなかった場合です（特殊なバッファ等）。
エラー / 例外
この関数は失敗すると E_NOTICE レベルのエラーを発行します。
例
例1 ob_end_flush() example
以下は全ての出力バッファをフラッシュし終了する簡単な方法の例です。
<?php
while (@ob_end_flush());
?>
参考
- ob_start() - 出力のバッファリングを有効にする
- ob_get_contents() - 出力用バッファの内容を返す
- ob_get_flush() - 出力バッファをフラッシュし、その内容を文字列として返した後で出力バッファリングを終了する
- ob_flush() - 出力バッファをフラッシュ(送信)する
- ob_end_clean() - 出力用バッファをクリア(消去)し、出力のバッファリングをオフにする
add a note
User Contributed Notes 9 notes
jhannus at 128kb dot com ¶
19 years ago
nico (at) nokes.de ¶
11 years ago
best way to compress a css code:
<?php
header('Content-type: text/css');
ob_start("compress");
function compress($buffer) {
// remove comments
$buffer = preg_replace('!/\*[^*]*\*+([^/][^*]*\*+)*/!', '', $buffer);
// remove tabs, spaces, newlines, etc.
$buffer = str_replace(array("\r\n", "\r", "\n", "\t", ' ', ' ', ' '), '', $buffer);
return $buffer;
}
include('./template/main.css');
include('./template/classes.css');
<?php
ob_end_flush();
?>
Include in <head>:
<link rel="stylesheet" type="text/css" href="/design.php" media="all" />
Mark ¶
13 years ago
Wanted to speed things up and put some processing after the page has been delivered to the client. That drove me almost insane, but finally, I found a solution (php 5.2.5):
<?php
ob_start(); // outer buffer
ob_start(); // inner buffer to catch URL rewrites and other post processing
session_start(); // registers URL rewriter with inner buffer!
echo '...';
// log performance data to log files *after* delivering the page!
register_shutdown_function(array($benchmarkclass,'log_perf_data'));
// now flush output output to client
ob_end_flush();
// need to calculate content length *after* URL rewrite!
header("Content-length: ".ob_get_length());
ob_end_flush();
// now we close the session and do some arbitrary clean-up tasks
// registered using register_shutdown_function()
session_write_close();
?>
skippy at zuavra dot net ¶
18 years ago
Apart from being mostly redundant, ob_end_flush() can be downright damaging in some weird cases.
Actual example: a particular page on an Intranet website which would appear blank on Internet Explorer 6 when ob_start('ob_gzhandler') was called in the beginning and ob_end_flush() at the end.
We couldn't figure out what made that page special no matter what we tried. The ob_ functions were placed in scripts which were include()'d by all pages just the same, but only that page did this.
Even stranger, the problem only appeared on direct browser/server connections. Whenever the connection passed through a proxy the problem dissapeared. I'm guessing some kind of HTTP encoding headers mumbo-jumbo.
Solution: unless you really need it in particular cases, remove the ob_end_flush() call and rely on the builtin, automatic buffer flush.
anatoliy at miraline dot com ¶
13 years ago
If you enable zlib.output_compression then level count will be increased by 1 and then this code:
<?php while (ob_get_level()) { ob_end_clean(); } ?>
will just freeze your script.
brett at realestate-school dot com ¶
21 years ago
It appears that you can call ob_end_flush() regardless of whether or not output buffering was ever started using ob_start(). This can prove useful because it saves you from having to create conditional statements based on whether a particular function or include file has started output buffering. You can simply call the ob_end_flush() anyway and if there's output in the buffer, it will be sent, otherwise your script will just keep on keepin' on.
shanep ¶
14 years ago
It appears that ob_end_flush() is very important if you are looping. For instance if you are using a mass mailer that uses the output buffer for creating HTML content. Use ob_end_flush() to avoid server errors.
kriek at jonkriek dot com ¶
21 years ago
ob_end_flush() isn't needed in MOST cases because it is called automatically at the end of script execution by PHP itself when output buffering is turned on either in the php.ini or by calling ob_start().
unxed ¶
14 years ago
Remember that chromium browser (and maybe other webkit-based browsers) have some issues with ob_end_flush.
http://code.google.com/p/chromium/issues/detail?id=31410
You may use
header("Content-Type: text/plain");
to solve those issues if you do not need html.
