fid value suppressing fprintf

I'd like to make a program to display something when it is in a debug mode. Say,

   fid = 0
   fprintf(fid, 'do not display this')

   fid = 1 % debug
   fprintf(fid, 'print this')

I already know that 1 is for stdout, 2 is for stderr. However, it doesn't work when fid == 0.

And I am curious that which number suppresses fprintf?

Answer 1

[Walter Roberson]

There is no fid the suppresses fprintf. Consider something like,

function dfprintf(DEBUG,varargin)
  DEBUG && fprintf(varargin{:});
end

with a small bit of work you can make DEBUG a shared variable and use

dfprintf = @(varargin) DEBUG && fprintf(varargin{:});

[Jeon]

Oh, that's sad. Thanks anyway.