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, 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
       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 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 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 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  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, 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
       original Standard can be obtained online at http://www.opengroup.org/unix/online.html .