ob_get_contents

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

    ob_get_contents — Return 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"

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    User Contributed Notes 4 notes

    up
    9
    Mark Clements
    10 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
    -4
    DrDreistein at dontknow dot at
    13 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
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