function comment = mm_comment_read ( input_unit )

%*****************************************************************************80
%
%% mm_comment_read() reads a comment from a Matrix Market file.
%
%  Discussion:
%
%    This routine simply reads one line from the file.  Comment
%    lines begin with a '%' character, and must occur between the
%    header line and the size line.  It is up to the user to 
%    examine the line returned by this routine, and, if it does not
%    begin with a comment character, then the user may do any of:
%    *) terminate the processing, because you simply wanted to see comments;
%    *) backspace the file, so the line can be processed by MM_SIZE_READ_FILE;
%    *) simply pass the line returned by this routine directly 
%       to MM_SIZE_READ_STRING.
%
%  Licensing:
%
%    This code is distributed under the MIT license.
%
%  Modified:
%
%    30 April 2004
%
%  Author:
%
%    John Burkardt
%
%  Input:
%
%    integer INPUT_UNIT, the input unit identifier.
%
%  Output:
%
%    character COMMENT, the next line of the file.
%    If COMMENT == -1, then the end of the file has been reached.
%
  comment = fgetl ( input_unit );

  return
end
