本篇文章是对ob_get_contents(),ob_end_clean(),ob_start(),的具体用法进行了详细的分析介绍，需要的朋友参考下
ob_get_contents();
ob_end_clean();
ob_start()
使用ob_start()把输出那同输出到缓冲区，而不是到浏览器。
然后用ob_get_contents得到缓冲区的数据。
ob_start()在服务器打开一个缓冲区来保存所有的输出。所以在任何时候使用echo ，输出都将被加入缓冲区中，直到程序运行结束或者使用ob_flush()来结束。然后在服务器中缓冲区的内容才会发送到浏览器，美国服务器，美国空间，由浏览器来解析显示。
函数ob_end_clean 会清除缓冲区的内容，美国服务器，并将缓冲区关闭，但不会输出内容。
此时得用一个函数ob_get_contents()在ob_end_clean()前面来获得缓冲区的内容。
这样的话，能将在执行ob_end_clean()前把内容保存到一个变量中，然后在ob_end_clean()后面对这个变量做操作。
这是eg：
ob_start(); // buf1
echo ' multiple ';
ob_start(); // buf2
echo ' buffers work ';
$buf2 = ob_get_contents();
ob_end_clean();
$buf1 = ob_get_contents();
ob_end_clean();
echo $buf1;
echo '
';
echo $buf2;
ob_get_contents
(php 4, php 5)
ob_get_contents -- return the contents of the output buffer
description
string ob_get_contents ( void )
this will return the contents of the output buffer or false, if output buffering isn't active.
see also ob_start() and ob_get_length().
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.
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 '';
naturally you can transfer whichever thing and not only images
ob_get_clean
(php 4 >= 4.3.0, php 5)
ob_get_clean -- get current buffer contents and delete current output buffer
description
string ob_get_clean ( void )
this will return the contents of the output buffer and end output buffering. if output buffering isn't active then false is returned. ob_get_clean() essentially executes both ob_get_contents() and ob_end_clean().
例子 1. a simple ob_get_clean() example
复制代码 代码如下:
our example will output: string(11) hello world
see also ob_start() and ob_get_contents().
notice that the function beneath does not catch errors, so throw in an @ before those ob_* calls
running php4 复制代码 代码如下: