PHP: Hypertext Preprocessor (original) (raw)

fflush

(PHP 4 >= 4.0.1, PHP 5, PHP 7, PHP 8)

fflush — Flushes the output to a file

Description

Parameters

stream

The file pointer must be valid, and must point to a file successfully opened by fopen() orfsockopen() (and not yet closed byfclose()).

Return Values

Returns [true](reserved.constants.php#constant.true) on success or [false](reserved.constants.php#constant.false) on failure.

Examples

Example #1 File write example using fflush()

<?php <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>f</mi><mi>i</mi><mi>l</mi><mi>e</mi><mi>n</mi><mi>a</mi><mi>m</mi><mi>e</mi><msup><mo>=</mo><mo mathvariant="normal" lspace="0em" rspace="0em">′</mo></msup><mi>b</mi><mi>a</mi><mi>r</mi><mi mathvariant="normal">.</mi><mi>t</mi><mi>x</mi><msup><mi>t</mi><mo mathvariant="normal" lspace="0em" rspace="0em">′</mo></msup><mo separator="true">;</mo></mrow><annotation encoding="application/x-tex">filename = 'bar.txt';</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.9463em;vertical-align:-0.1944em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mord mathnormal">i</span><span class="mord mathnormal" style="margin-right:0.01968em;">l</span><span class="mord mathnormal">e</span><span class="mord mathnormal">nam</span><span class="mord mathnormal">e</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel"><span class="mrel">=</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.7519em;"><span style="top:-3.063em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">′</span></span></span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.9463em;vertical-align:-0.1944em;"></span><span class="mord mathnormal">ba</span><span class="mord mathnormal" style="margin-right:0.02778em;">r</span><span class="mord">.</span><span class="mord mathnormal">t</span><span class="mord mathnormal">x</span><span class="mord"><span class="mord mathnormal">t</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.7519em;"><span style="top:-3.063em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">′</span></span></span></span></span></span></span></span></span><span class="mpunct">;</span></span></span></span>file = fopen($filename, 'r+'); rewind($file); fwrite($file, 'Foo'); fflush($file); ftruncate($file, ftell($file)); fclose($file); ?>

Found A Problem?

michaelsy01[NXSPAM] at informantum dot de ¶

6 years ago

A hint for PHP beginners like me: The buffered output which is write by fflush() has nothing to do with the output buffer which is initiated by the ob_start() function.