UNAME(1P) POSIX Programmer's Manual UNAME(1P)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.
NAMEuname — return system name
SYNOPSISuname [−amnrsv]
DESCRIPTION
By default, the uname utility shall write the operating system name to
standard output. When options are specified, symbols representing one
or more system characteristics shall be written to the standard output.
The format and contents of the symbols are implementation-defined. On
systems conforming to the System Interfaces volume of POSIX.1‐2008, the
symbols written shall be those supported by the uname() function as
defined in the System Interfaces volume of POSIX.1‐2008.
OPTIONS
The uname utility shall conform to the Base Definitions volume of
POSIX.1‐2008, Section 12.2, Utility Syntax Guidelines.
The following options shall be supported:
−a Behave as though all of the options −mnrsv were specified.
−m Write the name of the hardware type on which the system is
running to standard output.
−n Write the name of this node within an implementation-defined
communications network.
−r Write the current release level of the operating system
implementation.
−s Write the name of the implementation of the operating system.
−v Write the current version level of this release of the oper‐
ating system implementation.
If no options are specified, the uname utility shall write the operat‐
ing system name, as if the −s option had been specified.
OPERANDS
None.
STDIN
Not used.
INPUT FILES
None.
ENVIRONMENT VARIABLES
The following environment variables shall affect the execution of
uname:
LANG Provide a default value for the internationalization vari‐
ables that are unset or null. (See the Base Definitions vol‐
ume of POSIX.1‐2008, Section 8.2, Internationalization Vari‐
ables for the precedence of internationalization variables
used to determine the values of locale categories.)
LC_ALL If set to a non-empty string value, override the values of
all the other internationalization variables.
LC_CTYPE Determine the locale for the interpretation of sequences of
bytes of text data as characters (for example, single-byte as
opposed to multi-byte characters in arguments).
LC_MESSAGES
Determine the locale that should be used to affect the format
and contents of diagnostic messages written to standard
error.
NLSPATH Determine the location of message catalogs for the processing
of LC_MESSAGES.
ASYNCHRONOUS EVENTS
Default.
STDOUT
By default, the output shall be a single line of the following form:
"%s\n", <sysname>
If the −a option is specified, the output shall be a single line of the
following form:
"%s %s %s %s %s\n", <sysname>, <nodename>, <release>,
<version>, <machine>
Additional implementation-defined symbols may be written; all such sym‐
bols shall be written at the end of the line of output before the <new‐
line>.
If options are specified to select different combinations of the sym‐
bols, only those symbols shall be written, in the order shown above for
the −a option. If a symbol is not selected for writing, its correspond‐
ing trailing <blank> characters also shall not be written.
STDERR
The standard error shall be used only for diagnostic messages.
OUTPUT FILES
None.
EXTENDED DESCRIPTION
None.
EXIT STATUS
The following exit values shall be returned:
0 The requested information was successfully written.
>0 An error occurred.
CONSEQUENCES OF ERRORS
Default.
The following sections are informative.
APPLICATION USAGE
Note that any of the symbols could include embedded <space> characters,
which may affect parsing algorithms if multiple options are selected
for output.
The node name is typically a name that the system uses to identify
itself for inter-system communication addressing.
EXAMPLES
The following command:
uname −sr
writes the operating system name and release level, separated by one or
more <blank> characters.
RATIONALE
It was suggested that this utility cannot be used portably since the
format of the symbols is implementation-defined. The POSIX.1 working
group could not achieve consensus on defining these formats in the
underlying uname() function, and there was no expectation that this
volume of POSIX.1‐2008 would be any more successful. Some applications
may still find this historical utility of value. For example, the sym‐
bols could be used for system log entries or for comparison with opera‐
tor or user input.
FUTURE DIRECTIONS
None.
SEE ALSO
The Base Definitions volume of POSIX.1‐2008, Chapter 8, Environment
Variables, Section 12.2, Utility Syntax Guidelines
The System Interfaces volume of POSIX.1‐2008, uname()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 Electri‐
cal 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.ker‐
nel.org/doc/man-pages/reporting_bugs.html .
IEEE/The Open Group 2013 UNAME(1P)
