uname(1p) — Linux manual page

PROLOG | NAME | SYNOPSIS | DESCRIPTION | OPTIONS | OPERANDS | STDIN | INPUT FILES | ENVIRONMENT VARIABLES | ASYNCHRONOUS EVENTS | STDOUT | STDERR | OUTPUT FILES | EXTENDED DESCRIPTION | EXIT STATUS | CONSEQUENCES OF ERRORS | APPLICATION USAGE | EXAMPLES | RATIONALE | FUTURE DIRECTIONS | SEE ALSO | COPYRIGHT

UNAME(1P)               POSIX Programmer's Manual              UNAME(1P)

PROLOG         top

       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         top

       uname — return system name

SYNOPSIS         top

       uname [-amnrsv]

DESCRIPTION         top

       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.1‐2017, the symbols written shall be
       those supported by the uname() function as defined in the System
       Interfaces volume of POSIX.1‐2017.

OPTIONS         top

       The uname utility shall conform to the Base Definitions volume of
       POSIX.1‐2017, 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
                 operating system implementation.

       If no options are specified, the uname utility shall write the
       operating system name, as if the -s option had been specified.

OPERANDS         top

       None.

STDIN         top

       Not used.

INPUT FILES         top

       None.

ENVIRONMENT VARIABLES         top

       The following environment variables shall affect the execution of
       uname:

       LANG      Provide a default value for the internationalization
                 variables that are unset or null. (See the Base
                 Definitions volume of POSIX.1‐2017, Section 8.2,
                 Internationalization Variables 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         top

       Default.

STDOUT         top

       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 symbols shall be written at the end of the line of output
       before the <newline>.

       If options are specified to select different combinations of the
       symbols, only those symbols shall be written, in the order shown
       above for the -a option. If a symbol is not selected for writing,
       its corresponding trailing <blank> characters also shall not be
       written.

STDERR         top

       The standard error shall be used only for diagnostic messages.

OUTPUT FILES         top

       None.

EXTENDED DESCRIPTION         top

       None.

EXIT STATUS         top

       The following exit values shall be returned:

        0    The requested information was successfully written.

       >0    An error occurred.

CONSEQUENCES OF ERRORS         top

       Default.

       The following sections are informative.

APPLICATION USAGE         top

       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         top

       The following command:

           uname -sr

       writes the operating system name and release level, separated by
       one or more <blank> characters.

RATIONALE         top

       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.1‐2017 would be any more
       successful. Some applications may still find this historical
       utility of value. For example, the symbols could be used for
       system log entries or for comparison with operator or user input.

FUTURE DIRECTIONS         top

       None.

SEE ALSO         top

       The Base Definitions volume of POSIX.1‐2017, Chapter 8,
       Environment Variables, Section 12.2, Utility Syntax Guidelines

       The System Interfaces volume of POSIX.1‐2017, uname(3p)

COPYRIGHT         top

       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(1P)