/* --------------------------------------------------------------- */
/* younger -- test whether a stream (file) is newer than another   */
/* --------------------------------------------------------------- */
/*                                                                 */
/* Copyright (c) Mike Cowlishaw, 1990-2012.  All rights reserved.  */
/* Parts Copyright (c) IBM, 1990-2009.                             */
/*                                                                 */
/* Permission to use, copy, modify, and distribute this software   */
/* for any non-commercial purpose 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.            */
/*                                                                 */
/* --------------------------------------------------------------- */
/* Argument strings:                                               */
/*   stream1 -- first stream name (qualified or not)               */
/*   stream2 -- second stream name (qualified or not)              */
/*                                                                 */
/*   returns 1 if stream1 is younger (has a later date and time)   */
/*   than stream2, or 0 otherwise; if either stream does not exist */
/*   then 0 is returned.                                           */
/*                                                                 */
/* Times allow 2-seconds slop, to allow for Win9x <--> Win NT etc. */
/* conversions and related problems with FAT16 SD cards.           */
/*                                                                 */
/* --------------------------------------------------------------- */

/* Arg1 is main stream
   Arg2 is test stream. */
younger: -- procedure
  parse arg stream1, stream2
  t1=SysGetFileDateTime(stream1, "W")
  if t1='-1' then do
    --say "Warning: file '"stream1"' not found"
    return 0
    end

  t2=SysGetFileDateTime(stream2, "W")
  if t2='-1' then do
    --say "Warning: file '"stream2"' not found"
    return 0
    end

  -- say '1:' t1 stream1
  -- say '2:' t2 stream2

  parse var t1 date1 time1 .
  parse var t2 date2 time2 .

  if date1\=date2 then /* date mismatch */ do
    if date1<date2 then return 0
    return 1
    end
  /* date unchanged */
  if time1==time2 then return 0         /* time not changed */

  /* Allow 2 seconds slop, for NT<-->Win95 conversions */
  /* [Occasionally midnighters will over-copy] */
  parse var time1 h1':'m1':'s1
  parse var time2 h2':'m2':'s2
  secs1=h1*3600+m1*60+s1
  secs2=h2*3600+m2*60+s2
  if secs1<=secs2+2 then return 0       /* not 2 seconds more */
  return 1     /* younger */