function clear_persistent_variables(folder)

% Clear all the functions with persistent variables in directory folder (and subdirectories).

% Copyright (C) 2015 Dynare Team
%
% This file is part of Dynare.
%
% Dynare 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.
%
% Dynare 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 Dynare.  If not, see <http://www.gnu.org/licenses/>.

DYNARE_FOLDER = strrep(which('dynare'),'dynare.m','');

if ~nargin || isempty(folder)
    folder = pwd();
end

if ~exist('list_of_functions_to_be_cleared.mat') || isolder(sprintf('%slist_of_functions_to_be_cleared.mat', DYNARE_FOLDER), DYNARE_FOLDER)
    if isunix() || ismac()
        [status, output] = system(sprintf('grep -lr ^persistent %s', folder));
        list_of_files = strsplit(output);
        list_of_files(find(cellfun(@isempty, list_of_files))) = [];
    else
        [status, output] = system(sprintf('findstr /B/S/M persistent %s\\*', folder));
        list_of_files = strsplit(output);
        list_of_files(find(cellfun(@isempty, list_of_files))) = [];
        i = 1; mobius = true;
        while mobius
            if i>length(list_of_files)
                break
            end
            if ismember(list_of_files{i},{'FINDSTR:', 'ignored', '//'})
                list_of_files(i) = [];
            else
                i = i + 1;
            end
        end
    end
    [paths, list_of_functions, extensions] = cellfun(@fileparts, list_of_files, 'UniformOutput',false);
    save(sprintf('%slist_of_functions_to_be_cleared.mat', DYNARE_FOLDER), 'list_of_functions');
else
    load('list_of_functions_to_be_cleared');
end
    
clear(list_of_functions{:});