Mercurial > octave
view scripts/io/is_valid_file_id.m @ 30565:83f9f8bda883
maint: Merge stable to default.
author | John W. Eaton <jwe@octave.org> |
---|---|
date | Tue, 28 Dec 2021 18:59:33 -0500 |
parents | 83aeaba707d8 796f54d4ddbf |
children | 597f3ee61a48 |
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######################################################################## ## ## Copyright (C) 2010-2022 The Octave Project Developers ## ## See the file COPYRIGHT.md in the top-level directory of this ## distribution or <https://octave.org/copyright/>. ## ## 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 ## <https://www.gnu.org/licenses/>. ## ######################################################################## ## -*- texinfo -*- ## @deftypefn {} {@var{tf} =} is_valid_file_id (@var{fid}) ## Return true if @var{fid} refers to an open file. ## @seealso{freport, fopen} ## @end deftypefn function tf = is_valid_file_id (fid) if (nargin < 1) print_usage (); endif tf = false; try if (isscalar (fid)) [file, mode, arch] = fopen (fid); tf = ! isempty (file); endif end_try_catch endfunction %!assert (is_valid_file_id (stdout)) %!assert (! is_valid_file_id ([1,2;3,4])) %!assert (! is_valid_file_id ("not_a_file_id")) %!assert (! is_valid_file_id (-1)) %!assert (! is_valid_file_id (pi))