CascadiaPHP 2024


(PHP 8 >= 8.1.0)

fsyncSynchronizes changes to the file (including meta-data)


fsync(resource $stream): bool

This 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.

Elenco dei parametri


Il puntatore al file deve essere valido, e deve puntare ad un file aperto con successo da fopen() o fsockopen() (e non ancora chiuso da fclose()).

Valori restituiti

Restituisce true in caso di successo, false in caso di fallimento.


Example #1 fsync() example


= 'test.txt';

$stream = fopen($file, 'w');
fwrite($stream, 'test data');
fwrite($stream, "\r\n");
fwrite($stream, 'additional data');


Vedere anche:

  • fdatasync() - Synchronizes data (but not meta-data) to the file
  • fflush() - Invia l'output in un file

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User Contributed Notes 1 note

Dave Gebler
2 years ago
Two points 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.
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