Re: disp() to a file?

[John W. Eaton]

On 27-Jun-2000, Paul Kienzle <address@hidden> wrote:

| From: "John W. Eaton" <address@hidden>
| >
| >On  2-May-2000, Paul Kienzle <address@hidden> wrote:
| >
| >| How do I print to a file from an m-file without knowing the type of the
| >| thing I'm printing?  disp(x) works fine to the terminal.  I seem to want
| >| disp(x,fid).
| >
| >OK, in the current (2.1.x, CVS) sources, fdisp is now an M-file that
| >does this:
| >
| >  function fdisp (fid, x)
| >
| >    if (nargin == 2)
| >      fid << x << "\n";
| >    else
| >      usage ("fdisp (fid, x)");
| >    endif
| >
| >  endfunction
| > ...
| 
| Sorry to be so fickle, but I actually want it in a string.

OK, forget the M-file versions.  I now have the following code in
pr-output.cc.  Is this closer to what you want?

jwe


DEFUN (disp, args, nargout,
  "-*- texinfo -*-\n\
@deftypefn {Built-in Function} {} disp (@var{x})\n\
Display the value of @var{x}.  For example,\n\
\n\
@example\n\
disp (\"The value of pi is:\"), disp (pi)\n\
\n\
     @print{} the value of pi is:\n\
     @print{} 3.1416\n\
@end example\n\
\n\
@noindent\n\
Note that the output from @code{disp} always ends with a newline.\n\
\n\
If an output value is requested, @code{disp} prints nothing and\n\
returns the formatted output in a string.\n\
@end deftypefn\n\
@seealso{fdisp}")
{
  octave_value retval;

  int nargin = args.length ();

  if (nargin == 1 && nargout < 2)
    {
      if (nargout == 0)
        args(0).print (octave_stdout);
      else
        {
          std::ostrstream buf;
          args(0).print (buf);
          buf << ends;
          char *tmp = buf.str ();
          retval = tmp;
          delete [] tmp;
        }
    }
  else
    print_usage ("disp");

  return retval;
}

DEFUN (fdisp, args, ,
  "-*- texinfo -*-\n\
@deftypefn {Built-in Function} {} fdisp (@var{fid}, @var{x})\n\
Display the value of @var{x} on the stream @var{fid}.  For example,\n\
\n\
@example\n\
disp (stdout, \"The value of pi is:\"), disp (stdout, pi)\n\
\n\
     @print{} the value of pi is:\n\
     @print{} 3.1416\n\
@end example\n\
\n\
@noindent\n\
Note that the output from @code{disp} always ends with a newline.\n\
\n\
If an output value is requested, @code{disp} prints nothing and\n\
returns the formatted output in a string.\n\
@end deftypefn\n\
@seealso{disp}")
{
  octave_value retval;

  int nargin = args.length ();

  if (nargin == 2)
    {
      int fid = octave_stream_list::get_file_number (args (0));

      octave_stream os = octave_stream_list::lookup (fid, "fdisp");

      if (! error_state)
        {
          ostream *osp = os.output_stream ();

          if (osp)
            args(1).print (*osp);
          else
            error ("fdisp: stream not open for writing");
        }
    }
  else
    print_usage ("fdisp");

  return retval;
}



-----------------------------------------------------------------------
Octave is freely available under the terms of the GNU GPL.

Octave's home on the web:  http://www.che.wisc.edu/octave/octave.html
How to fund new projects:  http://www.che.wisc.edu/octave/funding.html
Subscription information:  http://www.che.wisc.edu/octave/archive.html
-----------------------------------------------------------------------