---
name: "subyte"
section: "9"
platform: "macos"
package: "xnu"
version: "12377.121.6"
release: "macOS 26.5"
platforms: ["linux", "freebsd", "macos"]
url: "https://new.carta.tech/store/9"
---

# subyte(9)

store data to user-space

Part of [store(9)](/store/9.md).

## NAME

**store**, **subyte**, **suibyte**, **suiword**, **sulong**, **suulong**, **suword** – store data to user-space

## SYNOPSIS

**#include \<sys/types.h\>**

**#include \<sys/time.h\>**

**#include \<sys/systm.h\>**

**#include \<sys/resourcevar.h\>**

*int*\

**subyte**(*user\_addr\_t addr*, *int byte*);

*int*\

**suibyte**(*user\_addr\_t addr*, *int byte*);

*int*\

**suiword**(*user\_addr\_t addr*, *int word*);

*int*\

**sulong**(*user\_addr\_t addr*, *int64\_t longword*);

*int*\

**suulong**(*user\_addr\_t addr*, *uint64\_t longword*);

*int*\

**suword**(*user\_addr\_t addr*, *int word*);

## DESCRIPTION

The **store** functions are designed to copy small amounts of data to user-space.

The **store** routines provide the following functionality:

- **subyte**()

  Stores a byte of data to the user-space address *addr*.

- **suibyte**()

  Stores a byte of data to the user-space address *addr*. This function is safe to call during an interrupt context.

- **suiword**()

  Stores a word of data to the user-space address *addr*. This function is safe to call during an interrupt context.

- **sulong**()

  Stores a long word of data to the user-space address *addr*.

- **suulong**()

  Stores a unsigned long word of data to the user-space address *addr*.

- **suword**()

  Stores a word of data to the user-space address *addr*.

## RETURN VALUES

The **store** functions return 0 on success or -1 on failure.

## SEE ALSO

[copy(9)](/copy/9.md), [fetch(9)](/fetch/9.md)