How to use ob_get_contents (), ob_end_clean (), ob_start () in PHP

Xiaobian to share with you how to use ob_get_contents(),ob_end_clean(),ob_start() in PHP, I believe most people still don't know how to use, so share this article for your reference, I hope you have a lot of harvest after reading this article, let's go to understand it together!

ob_get_contents();

ob_end_clean();

ob_start()

Use ob_start() to output that same to a buffer instead of to the browser.

Then use ob_get_contents to get the buffer data.

ob_start() opens a buffer on the server to hold all output. So anytime echo is used, the output will be added to the buffer until the program runs out or ob_flush() is used. The contents of the buffer in the server are then sent to the browser, which parses them for display.

The ob_end_clean function clears the contents of the buffer and closes the buffer, but does not output the contents.

In this case, ob_get_contents() is used before ob_end_clean() to obtain the contents of the buffer.

In this case, you can save the contents to a variable before executing ob_end_clean(), and then manipulate this variable after ob_end_clean().

This is 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().

Example 1. A simple ob_get_clean() example

The copy code is as follows:

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 < 4.3.0, you can simply add the following to use the function anyway:

The copy code is as follows:

The above is how to use ob_get_contents(),ob_end_clean(),ob_start() in PHP. Thank you for reading all the contents of this article! I believe that everyone has a certain understanding, hope to share the content to help everyone, if you still want to learn more knowledge, welcome to pay attention to the industry information channel!