(PHP 8 >= 8.1.0)
fsync — Synchronizes changes to the file (including meta-data)
$stream): boolThis function synchronizes changes to the file, including its meta-data. This is similar to fflush(), but it also instructs the operating system to write to the storage media.
streamThe file pointer must be valid, and must point to a file successfully opened by fopen() or fsockopen() (and not yet closed by fclose()).
Returns true on success or false on failure.
Example #1 fsync() example
<?php
$file = 'test.txt';
$stream = fopen($file, 'w');
fwrite($stream, 'test data');
fwrite($stream, "\r\n");
fwrite($stream, 'additional data');
fsync($stream);
fclose($stream);
?>