> For the complete documentation index, see [llms.txt](https://xiaoxiami.gitbook.io/swoole/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://xiaoxiami.gitbook.io/swoole/swoole-ji-chu/yi-bu-fei-du-sai-io/yi-bu-wen-jian-xi-tong-io-ff08-du-xie-wen-jian-ff09.md).

# 异步文件系统IO

建议先阅读官方文档[异步文件系统IO](https://wiki.swoole.com/wiki/page/183.html)章节

示例：

异步读文件

```php
<?php
$content = date("Ymd H:i:s").PHP_EOL;
swoole_async_writefile(__DIR__."/1.log", $content, function($filename){
    // todo
    echo "success".PHP_EOL;
}, FILE_APPEND);
echo "start".PHP_EOL;
```

异步写文件

```php
$content = date("Ymd H:i:s").PHP_EOL;
swoole_async_writefile(__DIR__."/1.log", $content, function($filename){
    // todo
    echo "success".PHP_EOL;
}, FILE_APPEND);
echo "start".PHP_EOL;
```