PHP 8.4.0 Alpha 2 available for testing

ob_get_contents

(PHP 4, PHP 5, PHP 7, PHP 8)

ob_get_contentsReturn the contents of the output buffer

Description

ob_get_contents(): string|false

Gets the contents of the output buffer without clearing it.

Parameters

This function has no parameters.

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

add a note

User Contributed Notes 5 notes

up
9
Mark Clements
9 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
10
mauroasprea+php at gmail dot com
13 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
-1
m227 ( at ) poczta dot onet dot pl
19 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
-5
DrDreistein at dontknow dot at
12 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
-21
http://www.francescosaf.altervista.org
19 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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