ob_get_level

    (PHP 4 >= 4.2.0, PHP 5, PHP 7, PHP 8)

    ob_get_level — Return the nesting level of the output buffering mechanism

    Description

    ob_get_level(): int

    Returns the nesting level of the output buffering mechanism.

    Parameters

    This function has no parameters.

    Return Values

    Returns the level of nested output buffering handlers or zero if output buffering is not active.

    Caution

    The value for identical levels between ob_get_level() and ob_get_status() is off by one. For ob_get_level() the first level is 1. Whereas for ob_get_status() the first level is 0.

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    User Contributed Notes 3 notes

    up
    55
    Anonymous
    12 years ago
    For users confused about getting "1" as a return value from ob_get_level at the beginning of a script: this likely means the PHP ini directive "output_buffering" is not set to off / 0. PHP automatically starts output buffering for all your scripts if this directive is not off (which acts as if you called ob_start on the first line of your script).

    If your scripts may end up on any server and you don't want end-users to have to configure their INI, you can use the following at the start of your script to stop output buffering if it's already started:
    <?php
    if (ob_get_level()) ob_end_clean();
    ?>

    Alternatively, you can use the opposite if you always want to have an output buffer at the start of your script:
    <?php
    if (!ob_get_level()) ob_start();
    ?>
    up
    10
    Anonymous
    9 years ago
    This can be used to handle exceptions properly when using output buffering for rendering a view which may or may not be using output buffering

    <?php

    function getView($view)
    {
    $level = ob_get_level();

    ob_start();

    try
    {
    include     $view;
    }

    catch (    Exception $e)
    {
    while (    ob_get_level() > $level)
    {
    ob_end_clean();
    }

    throw     $e;
    }

    return     ob_get_clean();
    }
    up
    2
    bonzini at gnu dot org
    20 years ago
    Even under older PHP, you can decide if output buffering is active (i.e. ob_get_level() > 0) using

    <?php $ob_active = ob_get_length () !== FALSE ?>

    Paolo
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