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.TH UNAME "3P" 2013 "IEEE/The Open Group" "POSIX Programmer's Manual"
.SH 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.

.SH NAME
uname
\(em get the name of the current system
.SH SYNOPSIS
.LP
.nf
#include <sys/utsname.h>
.P
int uname(struct utsname *\fIname\fP);
.fi
.SH DESCRIPTION
The
\fIuname\fR()
function shall store information identifying the current system in the
structure pointed to by
.IR name .
.P
The
\fIuname\fR()
function uses the
.BR utsname
structure defined in
.IR <sys/utsname.h> .
.P
The
\fIuname\fR()
function shall return a string naming the current system in the
character array
.IR sysname .
Similarly,
.IR nodename
shall contain the name of this node within an implementation-defined
communications network. The arrays
.IR release
and
.IR version
shall further identify the operating system. The array
.IR machine
shall contain a name that identifies the hardware that the system
is running on.
.P
The format of each member is implementation-defined.
.SH "RETURN VALUE"
Upon successful completion, a non-negative value shall be returned.
Otherwise, \(mi1 shall be returned and
.IR errno
set to indicate the error.
.SH ERRORS
No errors are defined.
.LP
.IR "The following sections are informative."
.SH EXAMPLES
None.
.SH "APPLICATION USAGE"
The inclusion of the
.IR nodename
member in this structure does not imply that it is sufficient
information for interfacing to communications networks.
.SH RATIONALE
The values of the structure members are not constrained to have any
relation to the version of this volume of POSIX.1\(hy2008 implemented in the operating
system. An application should instead depend on _POSIX_VERSION
and related constants defined in
.IR <unistd.h> .
.P
This volume of POSIX.1\(hy2008 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
.IR nodename
is not enough for use with many networks.
.P
The
\fIuname\fR()
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.
.P
4.3 BSD has
\fIgethostname\fR()
and
\fIgethostid\fR(),
which return a symbolic name and a numeric value, respectively. There
are related
\fIsethostname\fR()
and
\fIsethostid\fR()
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.
.SH "FUTURE DIRECTIONS"
None.
.SH "SEE ALSO"
The Base Definitions volume of POSIX.1\(hy2008,
.IR "\fB<sys_utsname.h>\fP"
.SH COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 7, Copyright (C) 2013 by the Institute of
Electrical and Electronics Engineers, Inc and The Open Group.
(This is POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) 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.unix.org/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 .
