uname(3p) — Linux manual page
UNAME(3P) POSIX Programmer's Manual UNAME(3P)
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(0p)
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 .
IEEE/The Open Group 2017 UNAME(3P)
Pages that refer to this page: sys_utsname.h(0p), uname(1p), gethostname(3p), posix_trace_attr_destroy(3p), posix_trace_attr_getclockres(3p)