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 (con-
       sult the corresponding Linux manual page for details of Linux behavior), or the  interface  may  not  be  implemented  on
       Linux.

NAME
       uname - return system name

SYNOPSIS
       uname [-snrvma]

DESCRIPTION
       By  default, the uname utility shall write the operating system name to standard output. When options are specified, sym-
       bols 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 IEEE Std 1003.1-2001,
       the symbols written shall be those supported by the uname() function as  defined  in  the  System  Interfaces  volume  of
       IEEE Std 1003.1-2001.

OPTIONS
       The  uname  utility  shall  conform  to the Base Definitions volume of IEEE Std 1003.1-2001, 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 speci-
       fied.

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 variables that are unset or null. (See the Base Definitions
              volume of IEEE Std 1003.1-2001, Section 8.2, Internationalization Variables for the precedence  of  international-
              ization 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 stan-
              dard 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 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>s 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>s, 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>s.

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 IEEE Std 1003.1-2001 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
       None.

SEE ALSO
       The System Interfaces volume of IEEE Std 1003.1-2001, uname()

COPYRIGHT
       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,  Copy-
       right (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   original   Standard   can   be   obtained  online  at  http://www.open-
       group.org/unix/online.html .



IEEE/The Open Group                                           2003                                                     UNAME(1P)