php缓冲输出实例分析

ob_start();????????? //打开缓冲区
echo "hello world";??????? //输出内容
$out=ob_get_clean();?????? //获得缓冲区内容并且结束缓冲区
$out=strtolower($out);?????? //将字符转换为小写
var_dump($out);??????? //输出结果
//
?
if(!function_exists('ob_clean'))????? //判断函数是否被定义
{
? function ob_clean()?????? //定义函数
? {
??? if(@ob_end_clean())
??? {
????? return ob_start();
??? }
??? trigger_error("ob_clean() failed to delete buffer.no buffer to delete.",e_user_notice);
??? return false;
? }
}
//
?
header('content-type: multipart/x-mixed-replace;boundary=endofsection');? //发送标头
print "n--endofsectionn";?????????? //输出内容
$pmt=array("-","","|","/");?????????? //定义数组
for($i=0;$i<10;$i++)??????????? //通过循环进行操作
{
? sleep(1);???????????? //暂停执行
? print "content-type: text/plainnn";???????? //输出内容
? print "part $it".$pmt[$i % 4];????????? //输出内容
? print "--endofsectionn";?????????? //输出内容
? ob_flush();???????????? //发送缓冲区数据
? flush();????????????? //刷新输出缓冲
}
print "content-type: text/plainnn";???????? //输出内容
print "the endn";??????????? //输出内容
print "--endofsection--n";?????????? //输出内容