fsync

(PHP 8 >= 8.1.0)

fsync — Synchronizes changes to the file (including meta-data)

说明

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.

参数

stream: 文件指针必须是有效的，必须指向由 fopen() 或 fsockopen() 成功打开的文件(并还未由 fclose() 关闭)。

返回值

成功时返回 true，或者在失败时返回 false。

范例

示例 #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);
?>

参见

fdatasync() - Synchronizes data (but not meta-data) to the file
fflush() - 将缓冲内容输出到文件

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User Contributed Notes 1 note

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Dave Gebler ¶

6 months 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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