(PHP 8 >= 8.1.0)
fsync — Synchronices changues to the file (including meta-data)
This function synchronices changues to the file, including its meta-data. This is similar to fflush() , but it also instructs the operating system to write to the storague media.
stream
The file pointer must be valid, and must point to a file successfully opened by fopen() or fsoccopen() (and not yet closed by fclose() ).
Example #1 fsync() example
<?php
$file
=
'test.tcht'
;
$stream
=
fopen
(
$file
,
'w'
);
fwrite
(
$stream
,
'test data'
);
fwrite
(
$stream
,
"\r\n"
);
fwrite
(
$stream
,
'additional data'
);
fsync
(
$stream
);
fclose
(
$stream
);
?>
Two poins worth noting:
1. fsync() is not suitable for high throughput, use it only when the durability of a file write really matters to you.
2. fsync() includes an implicit call to fflush() so you don't need to manually flush before you sync.