UNAME(P) POSIX Programmer's Manual UNAME(P)
uname - get the name of the current system
int uname(struct utsname *name);
The uname() function shall store information identifying the current system in the struc-
ture 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 implemen-
tation-defined communications network. The arrays release and version shall further iden-
tify 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.
Upon successful completion, a non-negative value shall be returned. Otherwise, -1 shall
be returned and errno set to indicate the error.
No errors are defined.
The following sections are informative.
The inclusion of the nodename member in this structure does not imply that it is suffi-
cient information for interfacing to communications networks.
The values of the structure members are not constrained to have any relation to the ver-
sion of this volume of IEEE Std 1003.1-2001 implemented in the operating system. An appli-
cation should instead depend on _POSIX_VERSION and related constants defined in
This volume of IEEE Std 1003.1-2001 does not define the sizes of the members of the struc-
ture 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.
The Base Definitions volume of IEEE Std 1003.1-2001, <sys/utsname.h>
Portions of this text are reprinted and reproduced in electronic form from IEEE Std
1003.1, 2003 Edition, Standard for Information Technology -- Portable Operating System
Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2003 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 orig-
inal Standard can be obtained online at http://www.opengroup.org/unix/online.html .
IEEE/The Open Group 2003 UNAME(P)