scripts/miscellaneous/computer.m

## Copyright (C) 2004, 2005, 2007, 2008 John W. Eaton
##
## This file is part of Octave.
##
## Octave is free software; you can redistribute it and/or modify it
## under the terms of the GNU General Public License as published by
## the Free Software Foundation; either version 3 of the License, or (at
## your option) any later version.
##
## Octave is distributed in the hope that it will be useful, but
## WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
## General Public License for more details.
##
## You should have received a copy of the GNU General Public License
## along with Octave; see the file COPYING.  If not, see
## <http://www.gnu.org/licenses/>.

## -*- texinfo -*-
## @deftypefn {Function File} {[@var{c}, @var{maxsize}, @var{endian}] =} computer ()
## Print or return a string of the form @var{cpu}-@var{vendor}-@var{os}
## that identifies the kind of computer Octave is running on.  If invoked
## with an output argument, the value is returned instead of printed.  For
## example,
##
## @example
## @group
## computer ()
##      @print{} i586-pc-linux-gnu
##
## x = computer ()
##      @result{} x = "i586-pc-linux-gnu"
## @end group
## @end example
##
## If two output arguments are requested, also return the maximum number
## of elements for an array.
##
## If three output arguments are requested, also return the byte order
## of the current system as a character (@code{"B"} for big-endian or
## @code{"L"} for little-endian).
## @end deftypefn

function [c, maxsize, endian] = computer ()

  if (nargin != 0)
    warning ("computer: ignoring extra arguments");
  endif

  msg = octave_config_info ("canonical_host_type");

  if (strcmp (msg, "unknown"))
    msg = "Hi Dave, I'm a HAL-9000";
  endif

  if (nargout == 0)
    printf ("%s\n", msg);
  else
    c = msg;
    if (strcmp (octave_config_info ("USE_64_BIT_IDX_T"), "true"))
      maxsize = 2^63-1;
    else
      maxsize = 2^31-1;
    endif
    if (octave_config_info ("words_big_endian"))
      endian = "B";
    elseif (octave_config_info ("words_little_endian"))
      endian = "L";
    else
      endian = "?";
    endif      
  endif

endfunction

%!assert((ischar (computer ())
%! && computer () == octave_config_info ("canonical_host_type")));

%!warning a =computer(2);