/* --------------------------------------------------------------- */
/* Return 1 if file or directory exists, 0 otherwise               */
/* --------------------------------------------------------------- */
/* Copyright (c) Mike Cowlishaw, 2010, 2013.  All rights reserved. */
/*                                                                 */
/* Permission to use, copy, modify, and/or distribute this         */
/* software for any purpose with or without fee is hereby granted, */
/* provided that the above copyright notice and this permission    */
/* notice appear in all copies, and that notice and the date of    */
/* any modifications be added to the software.                     */
/*                                                                 */
/* This software is provided "as is".  No warranties, whether      */
/* express, implied, or statutory, including, but not limited to,  */
/* implied warranties of merchantability and fitness for a         */
/* particular purpose apply to this software.  The author shall    */
/* not, in any circumstances, be liable for special, incidental,   */
/* or consequential damages, for any reason whatsoever.            */
/*                                                                 */
/* --------------------------------------------------------------- */
/*                                                                 */
/*   Arg1 is fully qualified file or directory name to test        */
/*                                                                 */
/* A file of size 0 is deemed not to exist.                        */
/* Note this cannot be used to test for root directory.            */
/* --------------------------------------------------------------- */
-- 'query exists' doesn't work for directories
exists:
  parse arg spec
  call sysfiletree spec, 'LIST', 'BL'
  if list.0\=1 then return 0            -- does not exist
  parse var list.1 . . size flags .
  if size>0 then return 1               -- real file
  return substr(flags, 2, 1)='D'        -- 1 if directory, 0 if zero-size file