---
name: "aio"
section: "4"
platform: "macos"
package: "xnu"
version: "12377.121.6"
release: "macOS 26.5"
platforms: ["linux", "freebsd", "macos"]
url: "https://new.carta.tech/aio/4"
---

# aio(4)

asynchronous I/O

## NAME

**aio** – asynchronous I/O

## DESCRIPTION

The **aio** facility provides system calls for asynchronous I/O.

## SEE ALSO

[aio\_cancel(2)](/aio_cancel/2.md), [aio\_error(2)](/aio_error/2.md), [aio\_read(2)](/aio_read/2.md), [aio\_return(2)](/aio_return/2.md), [aio\_suspend(2)](/aio_suspend/2.md), [aio\_write(2)](/aio_write/2.md), [lio\_listio(2)](/lio_listio/2.md)

## HISTORY

The **aio** facility appeared in FreeBSD 3.0.