UNAME(3POSIX)

📦 version 2017a, in debian bookworm, debian trixie, ubuntu jammy, ubuntu noble, ubuntu resolute, ubuntu stonking

💖 UNAME(3POSIX) — the POSIX Programmer's Manual, bestie edition 💖

okay so before we even get into it — this page lives inside the POSIX Programmer's Manual. Heads up tho: the Linux version of this interface might be a whole different girl (go read the matching Linux man page if you want the tea), or honestly it might not even be implemented on Linux at all. 🙈

✨ PROLOG ✨

This manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface may differ (consult the corresponding Linux manual page for details of Linux behavior), or the interface may not be implemented on Linux.

like… do your homework, babe. that's the vibe.

🌸 NAME 🌸

uname — get the name of the current system

🎀 SYNOPSIS 🎀

#include <sys/utsname.h>

int uname(struct utsname *name);

🦋 DESCRIPTION 🦋

So uname() shall store info that identifies the current system in the structure pointed to by name. That's it, that's the job. 💅

The uname() function uses the utsname structure defined in <sys/utsname.h>.

Here's the rundown of what lands where:

  • uname() shall return a string naming the current system in the character array sysname.
  • nodename shall contain the name of this node within an implementation-defined communications network.
  • The arrays release and version shall further identify the operating system.
  • The array machine shall contain a name that identifies the hardware that the system is running on.

And the format of each member? implementation-defined, bestie. Not our problem, not our business. 😌

💀 RETURN VALUE 💀

  • On success? A non-negative value shall be returned. Slay. ✨
  • Otherwise, -1 shall be returned and errno gets set to indicate the error. not slay. 😭

🌈 ERRORS 🌈

No errors are defined.

iconic behaviour honestly. nothing to report, your honour.

The following sections are informative.

🍓 EXAMPLES 🍓

None.

fr fr. nothing. empty. the void. 💀

💜 APPLICATION USAGE 💜

Just because nodename is sitting in this structure does not mean it's sufficient information for interfacing to communications networks. Do not use it like that, bestie, I'm begging. 🫶

👑 RATIONALE 👑

The values of the structure members are not constrained to have any relation to the version of this volume of POSIX.1‐2017 implemented in the operating system. So if you're trying to figure out which POSIX you're on — wrong door, babe — an application should instead depend on _POSIX_VERSION and related constants defined in <unistd.h>. ✨

This volume of POSIX.1‐2017 does not define the sizes of the members of the structure, and it permits them to be of different sizes, although most implementations define them all to be the same size: eight bytes plus one byte for the string terminator. And that size for nodename? Not enough for use with many networks. 😭 Tragic. Underbuilt. It's giving "we ran out of budget."

Now for the lore 🧚:

  • The uname() function originated in System III, System V, and related implementations.
  • It does not exist in Version 7 or 4.3 BSD. not invited to the party.
  • In those historical implementations, the values it returns are set at system compile time.

And more lore:

  • 4.3 BSD has gethostname() and gethostid(), which return a symbolic name and a numeric value, respectively.
  • There are related sethostname() and sethostid() functions that are used to set the values the other two functions return.
  • The former functions are included in this specification.
  • The latter are not.

so close. so close to having the whole set. 💅

🧚 FUTURE DIRECTIONS 🧚

None.

💖 SEE ALSO 💖

The Base Definitions volume of POSIX.1‐2017, <sys_utsname.h>

Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1-2017, Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 7, 2018 Edition, Copyright (C) 2018 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any discrepancy between this version and the original IEEE and The Open Group Standard, the original IEEE and The Open Group Standard is the referee document. The original Standard can be obtained online at http://www.opengroup.org/unix/online.html .

Any typographical or formatting errors that appear in this page are most likely to have been introduced during the conversion of the source files to man page format. To report such errors, see https://www.kernel.org/doc/man-pages/reporting_bugs.html .

okay that's the whole page bestie, we ate and left no crumbs 🫶 this was brought to you by IEEE/The Open Group, circa 2017, and the manual name on the tin is literally UNAME(3POSIX) — mwah, bye 💅✨

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