ConFoo 2025

fflush

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

fflushFlushes the output to a file

Description

fflush(resource $stream): bool

This function forces a write of all buffered output to the resource pointed to by the file stream.

Parameters

stream

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

Return Values

Returns true on success or false on failure.

Examples

Example #1 File write example using fflush()

<?php
$filename
= 'bar.txt';

$file = fopen($filename, 'r+');
rewind($file);
fwrite($file, 'Foo');
fflush($file);
ftruncate($file, ftell($file));
fclose($file);
?>

See Also

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User Contributed Notes 1 note

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19
michaelsy01[NXSPAM] at informantum dot de
5 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.
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