UNAME
Section: POSIX Programmer's Manual (3P)
Updated: 2017
Page Index
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.
NAME
uname
--- get the name of the current system
SYNOPSIS
#include <sys/utsname.h>
int uname(struct utsname *name);
DESCRIPTION
The
uname()
function shall store information identifying the current system in the
structure pointed to by
name.
The
uname()
function uses the
utsname
structure defined in
<sys/utsname.h>.
The
uname()
function shall return a string naming the current system in the
character array
sysname.
Similarly,
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.
The format of each member is implementation-defined.
RETURN VALUE
Upon successful completion, a non-negative value shall be returned.
Otherwise, -1 shall be returned and
errno
set to indicate the error.
ERRORS
No errors are defined.
The following sections are informative.
EXAMPLES
None.
APPLICATION USAGE
The inclusion of the
nodename
member in this structure does not imply that it is sufficient
information for interfacing to communications networks.
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. 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 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. That size for
nodename
is not enough for use with many networks.
The
uname()
function originated in System III, System V, and related
implementations,
and it does not exist in Version 7 or
4.3 BSD. The values it returns are set at system compile time in those
historical implementations.
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.
FUTURE DIRECTIONS
None.
SEE ALSO
The Base Definitions volume of POSIX.1-2017,
<sys_utsname.h>
COPYRIGHT
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 .