Re: Right C version for GCC

From	David Brown <david.brown@hesbynett.no>
Newsgroups	comp.lang.c
Subject	Re: Right C version for GCC
Date	2015-12-07 23:35 +0100
Organization	A noiseless patient Spider
Message-ID	<n451e1$3f5$1@dont-email.me> (permalink)
References	(13 earlier) <ebb1b3a4-359f-4a17-a91e-a6f0470c4041@googlegroups.com> <n44c3c$9lp$1@dont-email.me> <f2556db1-440b-42b3-89fb-1050a5713fa2@googlegroups.com> <n44q28$5hl$1@dont-email.me> <b68abf57-8049-4a14-a600-fc8eb210f47c@googlegroups.com>

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On 07/12/15 22:16, supercat@casperkitty.com wrote:
> On Monday, December 7, 2015 at 2:29:26 PM UTC-6, David Brown wrote:
>> You avoid that by protecting your signal lines from ESD.  Pick a level
>> of ESD protection suitable for the type of equipment you are making,
>> design the hardware properly, and test somewhat above and beyond the
>> requirements of the appropriate standard (not /too/ far above the
>> requirements, of course - extra protection is costly).  ESD cannot cause
>> a botched or partial reset as long as the equipment is used as designed.
>
> If the customer spec indicates that a device must accept transients of some
> size without behavioral disruption, and transients of some larger size
> without permanent damage, in what way would a device whose behavior is
> disrupted by transients between those sizes not be "properly designed"?
>

I can't figure out what you mean here.  But I can certainly tell you 
that relying on a watchdog to help behaviour on transients is not a good 
plan.

>> You design the hardware so that this will not happen.  It is not hard to
>> make a power supply that does not go up and down a few times on startup
>> - it is even easier to make a decent reset circuit that only releases
>> the microcontroller's reset after the power supply is stable.  If the
>> chip has a built-in brown-out protection that is good enough for the
>> job, use it - if not, make an external brown-out circuit.
>
> It's not hard if one is willing to tolerate an increase in quiescent power
> consumption.  If one is trying to design a device which runs off a single
> lithium cell and has a quiescent current below 10uA, it's much harder.

It may be hard, but not necessarily impossible.  And again, watchdogs 
don't help - they also consume valuable current.

>
>> (For the benefit of C programmers here who are not involved in
>> electronics design, this argument is about undefined behaviour in
>> electronics.  I am recommending that you make your electronics so that
>> undefined behaviour does not happen, and that your inputs are sanitised
>> before you use them - supercat apparently prefers to allow undefined
>> behaviour to happen in various ways, and pretend that he can safely
>> detect it and recover after it has happened.)
>
> It's interesting to note that on the hardware front, "undefined behavior"
> can sometimes be murky, though very few hardware vendors push "undefined
> behavior" quite as far as C compiler writers would like to.  Many devices,
> for example, guarantee that when certain things occur device operation
> will be *almost* unspecified unless or until certain conditions happen, but
> the devices will still abide by some constraints.  For example, if the
> setup or hold time of a flip-flop is violated, it may output any continuous
> or arbitrarily-changing voltage between VOL and VOH until the next valid
> clock edge, but it won't catch fire output voltages outside that range, or
> interfere with the operation of other nearby circuitry.  If one couldn't
> guarantee that the consequences of setup/hold violations would be bounded
> in such a fashion, it would be impossible for computers to safely perform
> any sort of asynchronous I/O.
>

Thread

Right C version for GCC "Morten W. Petersen" <morphex@gmail.com> - 2015-11-08 16:49 +0100
  Re: Right C version for GCC "Morten W. Petersen" <morphex@gmail.com> - 2015-11-08 19:29 +0100
  Re: Right C version for GCC Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-11-08 11:46 -0800
    Re: Right C version for GCC Jorgen Grahn <grahn+nntp@snipabacken.se> - 2015-11-08 20:03 +0000
      Re: Right C version for GCC Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-11-08 12:18 -0800
    Re: Right C version for GCC "Morten W. Petersen" <morphex@gmail.com> - 2015-11-08 21:14 +0100
      Re: Right C version for GCC Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-11-08 12:25 -0800
        Re: Right C version for GCC supercat@casperkitty.com - 2015-11-08 13:06 -0800
          Re: Right C version for GCC Philip Lantz <prl@canterey.us> - 2015-11-08 14:52 -0800
            Re: Right C version for GCC supercat@casperkitty.com - 2015-11-08 15:12 -0800
              Re: Right C version for GCC David Brown <david.brown@hesbynett.no> - 2015-11-09 09:38 +0100
              Re: Right C version for GCC Nick Bowler <nbowler@draconx.ca> - 2015-11-09 19:04 +0000
                Re: Right C version for GCC supercat@casperkitty.com - 2015-11-09 11:27 -0800
            Re: Right C version for GCC BartC <bc@freeuk.com> - 2015-11-09 00:00 +0000
        Re: Right C version for GCC Keith Thompson <kst-u@mib.org> - 2015-11-08 16:35 -0800
    Re: Right C version for GCC supercat@casperkitty.com - 2015-11-08 12:37 -0800
      Re: Right C version for GCC Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-11-08 12:58 -0800
        Re: Right C version for GCC supercat@casperkitty.com - 2015-11-08 13:19 -0800
    Re: Right C version for GCC Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-11-08 21:49 +0000
      Re: Right C version for GCC Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-11-08 14:14 -0800
        Re: Right C version for GCC Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-11-09 01:02 +0000
          Re: Right C version for GCC Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-11-09 02:26 -0800
            Re: Right C version for GCC David Brown <david.brown@hesbynett.no> - 2015-11-09 12:53 +0100
            Re: Right C version for GCC Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-11-09 15:00 +0000
              Re: Right C version for GCC Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-11-09 08:55 -0800
                Re: Right C version for GCC Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-11-09 17:07 +0000
                Re: Right C version for GCC supercat@casperkitty.com - 2015-11-09 09:51 -0800
                Re: Right C version for GCC jacobnavia <jacob@jacob.remcomp.fr> - 2015-11-09 19:01 +0100
                Re: Right C version for GCC "Morten W. Petersen" <morphex@gmail.com> - 2015-11-09 19:16 +0100
                Re: Right C version for GCC supercat@casperkitty.com - 2015-11-09 11:24 -0800
                Re: Right C version for GCC "Morten W. Petersen" <morphex@gmail.com> - 2015-11-09 20:30 +0100
                Re: Right C version for GCC jacobnavia <jacob@jacob.remcomp.fr> - 2015-11-09 20:40 +0100
            Re: Right C version for GCC Keith Thompson <kst-u@mib.org> - 2015-11-09 08:56 -0800
              Re: Right C version for GCC Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-11-09 09:41 -0800
                Re: Right C version for GCC gazelle@shell.xmission.com (Kenny McCormack) - 2015-11-09 17:44 +0000
                Re: Right C version for GCC Philipp Klaus Krause <pkk@spth.de> - 2015-11-09 18:53 +0100
                Re: Right C version for GCC Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-11-09 18:00 +0000
                Re: Right C version for GCC Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-11-09 10:27 -0800
                Re: Right C version for GCC Keith Thompson <kst-u@mib.org> - 2015-11-09 11:17 -0800
                Re: Right C version for GCC glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-11-09 22:59 +0000
                Re: Right C version for GCC Keith Thompson <kst-u@mib.org> - 2015-11-09 11:15 -0800
                Re: Right C version for GCC Philipp Klaus Krause <pkk@spth.de> - 2015-11-12 16:47 +0100
                Re: Right C version for GCC Keith Thompson <kst-u@mib.org> - 2015-11-12 09:24 -0800
                Re: Right C version for GCC Philipp Klaus Krause <pkk@spth.de> - 2015-11-13 12:54 +0100
                Re: Right C version for GCC Tim Rentsch <txr@alumni.caltech.edu> - 2015-11-13 12:01 -0800
                Re: Right C version for GCC Keith Thompson <kst-u@mib.org> - 2015-11-14 10:47 -0800
                Re: Right C version for GCC Philipp Klaus Krause <pkk@spth.de> - 2015-11-14 21:32 +0100
                Re: Right C version for GCC Tim Rentsch <txr@alumni.caltech.edu> - 2015-11-14 16:57 -0800
                Re: Right C version for GCC Keith Thompson <kst-u@mib.org> - 2015-11-09 11:07 -0800
                Re: Right C version for GCC "Morten W. Petersen" <morphex@gmail.com> - 2015-11-09 20:18 +0100
                Re: Right C version for GCC Keith Thompson <kst-u@mib.org> - 2015-11-09 11:27 -0800
                Re: Right C version for GCC "Morten W. Petersen" <morphex@gmail.com> - 2015-11-09 20:41 +0100
                Re: Right C version for GCC Keith Thompson <kst-u@mib.org> - 2015-11-09 12:07 -0800
                Re: Right C version for GCC "Morten W. Petersen" <morphex@gmail.com> - 2015-11-09 21:12 +0100
                Re: Right C version for GCC glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-11-09 23:13 +0000
                Re: Right C version for GCC James Kuyper <jameskuyper@verizon.net> - 2015-11-09 19:02 -0500
                Re: Right C version for GCC raltbos@xs4all.nl (Richard Bos) - 2015-11-10 17:52 +0000
                Re: Right C version for GCC glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-11-10 21:34 +0000
                Re: Right C version for GCC raltbos@xs4all.nl (Richard Bos) - 2015-11-17 22:28 +0000
                Re: Right C version for GCC glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-11-18 00:51 +0000
                Re: Right C version for GCC James Kuyper <jameskuyper@verizon.net> - 2015-11-17 22:26 -0500
                Re: Right C version for GCC Philipp Klaus Krause <pkk@spth.de> - 2015-11-18 11:06 +0100
                Re: Right C version for GCC Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-11-09 15:37 -0800
                Re: Right C version for GCC Ian Collins <ian-news@hotmail.com> - 2015-11-10 12:54 +1300
                Re: Right C version for GCC Keith Thompson <kst-u@mib.org> - 2015-11-09 16:14 -0800
                Re: Right C version for GCC supercat@casperkitty.com - 2015-11-09 16:37 -0800
                Re: Right C version for GCC Keith Thompson <kst-u@mib.org> - 2015-11-09 16:56 -0800
                Re: Right C version for GCC supercat@casperkitty.com - 2015-11-09 17:25 -0800
                Re: Right C version for GCC David Brown <david.brown@hesbynett.no> - 2015-11-10 10:37 +0100
                Re: Right C version for GCC Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-11-09 18:06 -0800
                Re: Right C version for GCC Keith Thompson <kst-u@mib.org> - 2015-11-09 18:51 -0800
                Re: Right C version for GCC supercat@casperkitty.com - 2015-11-10 08:40 -0800
                Re: Right C version for GCC raltbos@xs4all.nl (Richard Bos) - 2015-11-10 17:55 +0000
                Re: Right C version for GCC raltbos@xs4all.nl (Richard Bos) - 2015-11-10 17:50 +0000
                Re: Right C version for GCC "Morten W. Petersen" <morphex@gmail.com> - 2015-11-12 14:32 +0100
          Re: Right C version for GCC Jorgen Grahn <grahn+nntp@snipabacken.se> - 2015-11-09 10:35 +0000
      Re: Right C version for GCC Philipp Klaus Krause <pkk@spth.de> - 2015-11-08 23:57 +0100
        Re: Right C version for GCC "Morten W. Petersen" <morphex@gmail.com> - 2015-11-09 00:47 +0100
          Re: Right C version for GCC David Brown <david.brown@hesbynett.no> - 2015-11-09 13:01 +0100
            Re: Right C version for GCC "Morten W. Petersen" <morphex@gmail.com> - 2015-11-09 13:18 +0100
              Re: Right C version for GCC David Brown <david.brown@hesbynett.no> - 2015-11-09 14:01 +0100
        Re: Right C version for GCC Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-11-09 00:55 +0000
          Re: Right C version for GCC Jorgen Grahn <grahn+nntp@snipabacken.se> - 2015-11-09 10:42 +0000
            Re: Right C version for GCC Chad <cdalten@gmail.com> - 2015-11-09 03:03 -0800
              Re: Right C version for GCC Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-11-09 03:27 -0800
                Re: Right C version for GCC BartC <bc@freeuk.com> - 2015-11-09 12:28 +0000
                Re: Right C version for GCC Jorgen Grahn <grahn+nntp@snipabacken.se> - 2015-11-10 09:07 +0000
              Re: Right C version for GCC James Kuyper <jameskuyper@verizon.net> - 2015-11-09 07:37 -0500
            Re: Right C version for GCC Philipp Klaus Krause <pkk@spth.de> - 2015-11-09 16:57 +0100
      Re: Right C version for GCC David Brown <david.brown@hesbynett.no> - 2015-11-09 12:39 +0100
        Re: Right C version for GCC James Kuyper <jameskuyper@verizon.net> - 2015-11-09 13:18 -0500
          Re: Right C version for GCC David Brown <david.brown@hesbynett.no> - 2015-11-10 10:49 +0100
            Re: Right C version for GCC Les Cargill <lcargill99@comcast.com> - 2015-11-10 19:33 -0600
              Re: Right C version for GCC David Brown <david.brown@hesbynett.no> - 2015-11-11 13:34 +0100
                Re: Right C version for GCC supercat@casperkitty.com - 2015-11-11 06:53 -0800
    Re: Right C version for GCC Keith Thompson <kst-u@mib.org> - 2015-11-08 17:00 -0800
      Re: Right C version for GCC David Brown <david.brown@hesbynett.no> - 2015-11-09 13:37 +0100
      Re: Right C version for GCC Philipp Klaus Krause <pkk@spth.de> - 2015-11-09 13:53 +0100
    Re: Right C version for GCC BartC <bc@freeuk.com> - 2015-11-09 21:54 +0000
      Re: Right C version for GCC Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-11-09 15:45 -0800
        Re: Right C version for GCC David Brown <david.brown@hesbynett.no> - 2015-11-10 11:14 +0100
          Re: Right C version for GCC BartC <bc@freeuk.com> - 2015-11-10 10:53 +0000
          Re: Right C version for GCC Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-11-10 03:14 -0800
            Re: Right C version for GCC David Brown <david.brown@hesbynett.no> - 2015-11-10 13:00 +0100
              Re: Right C version for GCC BartC <bc@freeuk.com> - 2015-11-10 12:39 +0000
                Re: Right C version for GCC David Brown <david.brown@hesbynett.no> - 2015-11-10 15:11 +0100
                Re: Right C version for GCC Philipp Klaus Krause <pkk@spth.de> - 2015-11-10 16:16 +0100
                Re: Right C version for GCC David Brown <david.brown@hesbynett.no> - 2015-11-10 16:35 +0100
                Re: Right C version for GCC supercat@casperkitty.com - 2015-11-10 08:54 -0800
                Re: Right C version for GCC David Brown <david.brown@hesbynett.no> - 2015-11-10 18:56 +0100
                Re: Right C version for GCC Philipp Klaus Krause <pkk@spth.de> - 2015-11-10 23:27 +0100
                Re: Right C version for GCC raltbos@xs4all.nl (Richard Bos) - 2015-11-17 22:32 +0000
                Re: Right C version for GCC David Brown <david.brown@hesbynett.no> - 2015-11-18 08:44 +0100
                Re: Right C version for GCC raltbos@xs4all.nl (Richard Bos) - 2015-11-19 10:43 +0000
                Re: Right C version for GCC David Brown <david.brown@hesbynett.no> - 2015-11-19 12:29 +0100
                Re: Right C version for GCC raltbos@xs4all.nl (Richard Bos) - 2015-11-20 11:01 +0000
                Re: Right C version for GCC David Brown <david.brown@hesbynett.no> - 2015-11-21 15:50 +0100
                Re: Right C version for GCC Philipp Klaus Krause <pkk@spth.de> - 2015-11-18 11:13 +0100
              Re: Right C version for GCC Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-11-10 07:25 -0800
                Re: Right C version for GCC David Brown <david.brown@hesbynett.no> - 2015-11-10 16:42 +0100
                Re: Right C version for GCC supercat@casperkitty.com - 2015-11-10 08:48 -0800
                Re: Right C version for GCC Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-11-11 01:08 -0800
                Re: Right C version for GCC David Brown <david.brown@hesbynett.no> - 2015-11-11 13:43 +0100
                Re: Right C version for GCC Les Cargill <lcargill99@comcast.com> - 2015-11-11 08:27 -0600
                Re: Right C version for GCC David Brown <david.brown@hesbynett.no> - 2015-11-11 16:27 +0100
                Re: Right C version for GCC David Thompson <dave.thompson2@verizon.net> - 2015-12-06 07:57 -0500
                Re: Right C version for GCC David Brown <david.brown@hesbynett.no> - 2015-12-06 22:34 +0100
                Re: Right C version for GCC Jorgen Grahn <grahn+nntp@snipabacken.se> - 2015-12-06 22:41 +0000
                Re: Right C version for GCC David Brown <david.brown@hesbynett.no> - 2015-12-07 09:47 +0100
                Re: Right C version for GCC supercat@casperkitty.com - 2015-12-07 07:30 -0800
                Re: Right C version for GCC David Brown <david.brown@hesbynett.no> - 2015-12-07 17:30 +0100
                Re: Right C version for GCC supercat@casperkitty.com - 2015-12-07 10:17 -0800
                Re: Right C version for GCC David Brown <david.brown@hesbynett.no> - 2015-12-07 21:29 +0100
                Re: Right C version for GCC supercat@casperkitty.com - 2015-12-07 13:16 -0800
                Re: Right C version for GCC David Brown <david.brown@hesbynett.no> - 2015-12-07 23:35 +0100
                Re: Right C version for GCC jadill33@gmail.com - 2015-12-07 10:41 -0800
                Re: Right C version for GCC David Brown <david.brown@hesbynett.no> - 2015-12-07 21:35 +0100
  Re: Right C version for GCC Jorgen Grahn <grahn+nntp@snipabacken.se> - 2015-11-08 20:11 +0000
  Re: Right C version for GCC Ian Collins <ian-news@hotmail.com> - 2015-11-09 09:57 +1300
    Re: Right C version for GCC Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-11-08 13:06 -0800
      Re: Right C version for GCC Ian Collins <ian-news@hotmail.com> - 2015-11-09 10:16 +1300
        Re: Right C version for GCC "Morten W. Petersen" <morphex@gmail.com> - 2015-11-08 22:59 +0100
          Re: Right C version for GCC Ian Collins <ian-news@hotmail.com> - 2015-11-09 12:13 +1300
            Re: Right C version for GCC "Morten W. Petersen" <morphex@gmail.com> - 2015-11-09 00:43 +0100
              Re: Right C version for GCC Ian Collins <ian-news@hotmail.com> - 2015-11-09 13:00 +1300
                Re: Right C version for GCC "Morten W. Petersen" <morphex@gmail.com> - 2015-11-09 12:02 +0100
                Re: Right C version for GCC Keith Thompson <kst-u@mib.org> - 2015-11-09 09:00 -0800
                Re: Right C version for GCC Ian Collins <ian-news@hotmail.com> - 2015-11-10 07:25 +1300
                Re: Right C version for GCC "Morten W. Petersen" <morphex@gmail.com> - 2015-11-09 19:35 +0100
                Re: Right C version for GCC Ian Collins <ian-news@hotmail.com> - 2015-11-10 08:55 +1300
                Re: Right C version for GCC "Morten W. Petersen" <morphex@gmail.com> - 2015-11-09 21:00 +0100
                Re: Right C version for GCC Ian Collins <ian-news@hotmail.com> - 2015-11-10 09:04 +1300
                Re: Right C version for GCC "Morten W. Petersen" <morphex@gmail.com> - 2015-11-09 21:11 +0100
                Re: Right C version for GCC Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-11-09 20:18 +0000
                Re: Right C version for GCC "Morten W. Petersen" <morphex@gmail.com> - 2015-11-09 21:21 +0100
                Re: Right C version for GCC Ian Collins <ian-news@hotmail.com> - 2015-11-10 09:30 +1300
                Re: Right C version for GCC Keith Thompson <kst-u@mib.org> - 2015-11-09 12:53 -0800
                Re: Right C version for GCC Keith Thompson <kst-u@mib.org> - 2015-11-09 12:30 -0800
                Re: Right C version for GCC supercat@casperkitty.com - 2015-11-09 13:02 -0800
                Re: Right C version for GCC BartC <bc@freeuk.com> - 2015-11-09 21:35 +0000
                Re: Right C version for GCC supercat@casperkitty.com - 2015-11-09 14:41 -0800
                Re: Right C version for GCC BartC <bc@freeuk.com> - 2015-11-09 23:31 +0000
                Re: Right C version for GCC supercat@casperkitty.com - 2015-11-09 16:33 -0800
                Re: Right C version for GCC David Brown <david.brown@hesbynett.no> - 2015-11-10 11:16 +0100
                Re: Right C version for GCC Ian Collins <ian-news@hotmail.com> - 2015-11-11 08:04 +1300
                Re: Right C version for GCC raltbos@xs4all.nl (Richard Bos) - 2015-11-10 18:04 +0000
                Re: Right C version for GCC raltbos@xs4all.nl (Richard Bos) - 2015-11-10 18:03 +0000
                Re: Right C version for GCC Ian Collins <ian-news@hotmail.com> - 2015-11-11 08:23 +1300
          Re: Right C version for GCC David Brown <david.brown@hesbynett.no> - 2015-11-09 13:41 +0100
      Re: Right C version for GCC supercat@casperkitty.com - 2015-11-08 13:24 -0800
      Re: Right C version for GCC "Morten W. Petersen" <morphex@gmail.com> - 2015-11-08 23:00 +0100
        Re: Right C version for GCC Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-11-08 15:18 -0800
          Re: Right C version for GCC "Morten W. Petersen" <morphex@gmail.com> - 2015-11-09 00:35 +0100
          Re: Right C version for GCC Keith Thompson <kst-u@mib.org> - 2015-11-08 17:03 -0800
            Re: Right C version for GCC Jorgen Grahn <grahn+nntp@snipabacken.se> - 2015-11-09 12:42 +0000
  Re: Right C version for GCC Keith Thompson <kst-u@mib.org> - 2015-11-08 17:51 -0800
  Re: Right C version for GCC Les Cargill <lcargill99@comcast.com> - 2015-11-09 12:20 -0600
    Re: Right C version for GCC "Morten W. Petersen" <morphex@gmail.com> - 2015-11-09 19:36 +0100
    Re: Right C version for GCC BartC <bc@freeuk.com> - 2015-11-09 18:47 +0000
  Re: Right C version for GCC Stephen Sprunk <stephen@sprunk.org> - 2015-11-11 00:55 -0600
    Re: Right C version for GCC "Morten W. Petersen" <morphex@gmail.com> - 2015-11-12 14:39 +0100

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