UNAME(3)                   POSIX Programmer's Manual                  UNAME(3)



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

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 .



IEEE/The Open Group                  2017                             UNAME(3)
