(PHP 4, PHP 5)
ob_get_contents — 返回输出缓冲区的内容
只是得到输出缓冲区的内容，但不清除它。
此函数返回输出缓冲区的内容，或者如果输出缓冲区无效将返回FALSE 。
Example #1 A simple ob_get_contents() example
<?php
ob_start();
echo "Hello ";
$out1 = ob_get_contents();
echo "World";
$out2 = ob_get_contents();
ob_end_clean();
var_dump($out1, $out2);
?>
以上例程会输出：
string(6) "Hello " string(11) "Hello World"
jannik dot zappe at udo dot edu (2013-06-10 09:19:39)
If anyone plans on using the flag "LOCK_EX", be aware that this only applies to the level of PHP-file handling. A Systemuser ,e.g. the root, CAN ALTER and DELETE the file you have a lock on!
DrDreistein at dontknow dot at (2011-10-04 16:07:45)
i made a simple test which is faster: adding some text in the normal way or by the ob stack:
<?php
$start = microtime(true);
$var = '';
for($i=0 ; $i <= 1000000 ; $i++) {
$var .= ' ';
}
$middle = microtime(true);
ob_start();
for($i=0 ; $i <= 1000000 ; $i++) {
echo ' ';
}
$var = ob_get_contents();
ob_end_clean();
$end = microtime(true);
echo $middle - $start;
echo '<br />';
echo $end - $middle;
?>
Outputs something like this:
0.33658003807068
0.30778789520264
mauroasprea+php at gmail dot com (2010-12-30 08:10:43)
This is an example of how the stack works:
<?php
//Level 0
ob_start();
echo "Hello ";
//Level 1
ob_start();
echo "Hello World";
$out2 = ob_get_contents();
ob_end_clean();
//Back to level 0
echo "Galaxy";
$out1 = ob_get_contents();
ob_end_clean();
//Just output
var_dump($out1, $out2);
?>
m227 ( at ) poczta dot onet dot pl (2005-02-24 06:53:05)
if you use ob_start with a callback function as a parameter, and that function changes ob string (as in example in manual) don't expect that ob_get_contents will return changed ob.
it will work as you would use ob_start with no parameter at all. So don't be confused.
http://www.francescosaf.altervista.org (2005-02-08 02:04:21)
transfer image, another method (alternative to fsockopen or function socket) :
server(192.168.0.1)
makeimage.php
...........
...........
$nameimage="xxxx.jpg"
$comand=exec("plotvelocity.sh $nameimage $paramater1 $paramater2");
ob_start();
readfile($nameimage);
$image_data = ob_get_contents();
ob_end_clean();
echo $image_data;
unlink($nameimage);
Client (192.168.0.2)
$bild="images/newimage2.gif";
$host="192.168.0.1";
$url=file_get_contents("http://$host/makeimage.php?$querystring");
$fp = fopen("$bild", 'wb');
fwrite($fp, $url);
fclose($fp);
echo '<img src="'.$bild.'">';
naturally you can transfer whichever thing and not only images