ob_get_contents

(PHP 4, PHP 5, PHP 7)

ob_get_contentsReturn the contents of the output buffer

Description

ob_get_contents ( void ) : string

Gets the contents of the output buffer without clearing it.

Return Values

This will return the contents of the output buffer or FALSE, if output buffering isn't active.

Examples

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);
?>

The above example will output:

string(6) "Hello "
string(11) "Hello World"

See Also

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User Contributed Notes 6 notes

up
16
mauroasprea+php at gmail dot com
8 years ago
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);
?>
up
0
Mark Clements
4 years ago
Note that, unlike PHP variables which make efficient use of memory, getting the contents of the output buffer results in a new copy of the buffer being made.  This can end up massively increasing the memory requirements of your script if your output is large.

Example code:

<?php

print(memory_get_usage() . "<br>");

ob_start();

for (
$i = 0; $i < 5000000; $i++)
    print(
" ");

print(
memory_get_usage() . "<br>");

$foo = ob_get_contents();

print(
memory_get_usage() . "<br>");

ob_end_flush();

?>

Output:

  351664
5359152
10359256
up
-1
ipfound at gmail dot com
4 years ago
The ob_get_contents() function has different return behaivor in PHP 5.3.x and PHP 5.5.x. Take a look at very simple example for PHP 5.3

<?php
var_dump
(ob_get_contents());
?>
Output: bool(false)

but in PHP 5.5.x, the same php code will return:
Output: string (0) ""

Actually, we can use type regulation - intval(ob_get_contents()), for cheking On/Off output buffering, but it lays the possible problems in the future.
up
-4
DrDreistein at dontknow dot at
7 years ago
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
up
-4
m227 ( at ) poczta dot onet dot pl
14 years ago
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.
up
-14
http://www.francescosaf.altervista.org
14 years ago
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
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