function [hdr] = neuralynx_getheader(filename)

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% SUBFUNCTION for reading the 16384 byte header from any Neuralynx file
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

% Copyright (C) 2007, Robert Oostenveld
%
% This file is part of FieldTrip, see http://www.ru.nl/neuroimaging/fieldtrip
% for the documentation and details.
%
%    FieldTrip 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.
%
%    FieldTrip 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 FieldTrip. If not, see <http://www.gnu.org/licenses/>.
%
% $Id: neuralynx_getheader.m 9663 2014-06-22 07:06:19Z roboos $

fid     = fopen(filename, 'rb', 'ieee-le');
buf     = fread(fid, 16*1024, 'uint8=>char');
fclose(fid);

buf     = buf(:)';
nl      = find(buf==10);    % determine the new-lines
cr      = find(buf==13);    % determine the carriage-returns
begchar = [1 nl(1:(end-1))];
endchar = nl - 1;
num     = length(nl);

hdr        = [];
hdr.Header = buf; % remember the full header in its original format

for i=1:num
  line = fliplr(deblank(fliplr(deblank(char(buf(begchar(i):endchar(i)))))));
  if numel(line)==0
    % line is empty
    continue
  elseif line(1)=='#'
    % line contains a comment
    continue
  else
    % strip the '-' sign
    while line(1)=='-'
      line = line(2:end);
    end
    % replace tabs with spaces
    line(find(line==9)) = ' ';
    % cut into pieces
    item = strread(line, '%s');
    if length(item)==2
      key = item{1};
      val = item{2};
      if any(val(1)=='-01234567989')
        % try to convert to number
        val = str2num(val);
        if isempty(val)
          % revert to the original text
          val = item{2};
        end
      end
      % remove unuseable characters from the variable name (key)
      key = key(key~=':');
      % assign the value to the header structure
      indx =  strfind(key,char(181)); % avoid problems with this field in the new Neuralynx header      
      if ~isempty(indx)
        key(indx) = 'm';
      end
      hdr = setfield(hdr, key, val);
    end
  end
end

