ob_get_length

(PHP 4 >= 4.0.2, PHP 5, PHP 7, PHP 8)

ob_get_length — 返回输出缓冲区内容的长度

说明

ob_get_length(): int

此函数将返回输出缓中冲区内容的长度。

返回值

返回输出缓冲区内容的长度；或者返回false——如果没有起作用的缓冲区。

范例

示例 #1 A simple ob_get_length() example


<?php

ob_start();

echo "Hello ";

$len1 = ob_get_length();

echo "World";

$len2 = ob_get_length();

ob_end_clean();

echo $len1 . ", ." . $len2;
?>

以上例程会输出：

6, 11

参见

ob_start() - 打开输出控制缓冲
ob_get_contents() - 返回输出缓冲区的内容

add a note

User Contributed Notes 5 notes

down

Nitrogen ¶

13 years ago


I use this function to produce a small speed test in my pages since I run my website from my home computers.

<?php
ob_start();
$StartTime=microtime(1);
?>
.. webpage data goes here ..

<?php
// footer?
printf("%s seconds to produce (%skb/sec)",
  microtime(1)-$StartTime,
  Round((ob_get_length()/(microtime(1)-$StartTime))/1024));

ob_end_flush();
?>

Note: don't forget the "speed" depends on how quick the content is actually generated and not on the speed the data is sent to the client..
However it would be good to see such function to get the real speed. :)

Nitrogen.

down

rush at logic dot cz ¶

16 years ago


There is a work-around for the situation you need to get length of the gz-ed buffer.

ob_start();
ob_start('ob_gzhandler');

  ... output the page content...

ob_end_flush();  // The ob_gzhandler one

header('Content-Length: '.ob_get_length());

ob_end_flush();  // The main one

more info at http://www.edginet.org/techie/website/http.html

down

stangelanda at arrowquick dot com ¶

14 years ago


If you don't buffer your output, it doesn't seem like it would be possible for a web server to output a Content-Length header.  For static files it can check the filesize, but for dynamic files that send output a little by little there is no way to know how many bytes it is going to output.  And the headers have to be sent before a single byte is output.

Also if you're wondering why the Content-Length is important, the browser doesn't close the connection as long as the script is running.  So if you register time consuming shutdown functions, the browser will still 'spin' waiting for more content until they complete.  (I'm not sure this happens under all conditions, but I am certain the sending the Content-Length always prevents this.)

You might take note that this manual page does not currently output any Content-Length header.

Alternatively using mb_strlen($output, 'latin1') seems to work to determine bytes in a string.  strlen may or may not depending on if it has been set up as a multibyte or not.

down

Sinured ¶

14 years ago


> Dude, your web server will compute Content-length for you!

I've noticed that Apache 1.3 doesn't do that.
However, if you’re running Apache 2.2 (and maybe 2.0, haven't experienced that yet) you don't need to worry about Content-Length.

down

-4

webmaster at crescentart dot com ¶

20 years ago


Here is an easy way to get the header Content-Lenght.

<?

ob_start();

?>


Put HTML tags.


<?

$size=ob_get_length();

header("Content-Length: $size");

ob_end_flush();

?>

add a note

官方地址：https://www.php.net/manual/en/function.ob-get-length.php

有任何技术问题请点击这里网站运营推广招聘

IT PHP 编程语言 Linux 开发编程科技 Elasticsearch HTML/CSS/XML 网络数据库 JAVA 面试 NoSQL C/C++ Golang Git 算法操作系统正则表达式 Redis 互联网 MySql JavaScript 运维软件国际架构设计 Mac OS TCP/IP Excel Vim Windows Socket Oracle VR MongoDB Python 运营 MemCache 商业硬件电子娱乐设计 nginx 摄影游戏 WordPress HTTP 团建数码电器

php7 安装fileinfo扩展 preg_split — 通过一个正则表达式分隔字符串 php位值,解决 PHP 中 usort 在值相同时改变原始位置的问题 [PHP] inet_pton/inet_ntop IP地址转换函数 PHP 8.1 [鸟哥]PHP_INT_MIN 和 -9223372036854775808 ADORecordSet对象 adodb手册 opcache预加载 Composer的Packagist资源 array_multisort() 多字段排序 PHPMailer设置utf8 PHPMailer字符集CharSet PHP json解析（json_decode）页面工具 mysql面试题 [原创]诡异的php-fpm超时问题 php中几种注释规范纯php实现DES以及TripleDES加密算法 php 修改图片大小支持php7的性能采集扩展 PHP mkdir()写出来的权限与mode值不符合

略微加速

PHP官方手册 - 互联网笔记

ob_get_length

说明

返回值

范例

参见

User Contributed Notes 5 notes