---
name: "uname"
section: "3"
platform: "freebsd"
package: "base"
version: "16.0-CURRENT-20261027-61c70dc16a79"
release: "FreeBSD 16.0-CURRENT (2026-10-27)"
platforms: ["freebsd", "macos"]
url: "https://new.carta.tech/uname/3"
---

# uname(3)

get system identification

## NAME

**uname** – get system identification

## LIBRARY

Standard C Library (libc, -lc)

## SYNOPSIS

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

*int*\

**uname**(*struct utsname \*name*);

## DESCRIPTION

The **uname**() function stores NUL-terminated strings of information identifying the current system into the structure referenced by *name*.

The *utsname* structure is defined in the ⟨sys/utsname.h⟩ header file, and contains the following members:

- sysname

  Name of the operating system implementation.

- nodename

  Network name of this machine.

- release

  Release level of the operating system.

- version

  Version level of the operating system.

- machine

  Machine hardware platform.

## RETURN VALUES

The **uname()** function returns the value 0 if successful; otherwise the value -1 is returned and the global variable errno is set to indicate the error.

## ENVIRONMENT

- UNAME\_s

  If the environment variable UNAME\_s is set, it will override the *sysname* member.

- UNAME\_r

  If the environment variable UNAME\_r is set, it will override the *release* member.

- UNAME\_v

  If the environment variable UNAME\_v is set, it will override the *version* member.

- UNAME\_m

  If the environment variable UNAME\_m is set, it will override the *machine* member.

## ERRORS

The **uname**() function may fail and set *errno* for any of the errors specified for the library functions [sysctl(3)](/sysctl/3.md).

## SEE ALSO

[uname(1)](/uname/1.md), [sysctl(3)](/sysctl/3.md)

## STANDARDS

The **uname**() function conforms to IEEE Std 1003.1-1988 (“POSIX.1”).

## HISTORY

The **uname**() function first appeared in 4.4BSD.