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Re: ot: on stdin, stdout, stderr and crlf on windows

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Mike Terry <news.dead.person.stones@darjeeling.plus.com> writes:

[...]

>>>> I looked for a confirmation of this apparent fact and could not find
>>>> it.  Can you advise?  I don't see the replacements taking place; only
>>>> on stdout it seems to happen.  I'm not sure how to prove that.
>>>> Here's my attempt.  This program below shows all bytes it reads from
>>>> stdin.  C:\tmp>cat show-c.c #include <stdio.h> int main() { int c;
>>>> while ( (c = getchar()) != EOF) { printf("%d", c); } printf("\n"); }
>>>> C:\tmp>show-c.exe < empty.txt 10 So empty.txt must contain at least
>>>> byte 10.  But if Windows were fixing my line-terminations, it should
>>>> have added a byte 13 (on my back).
>>>
>>> This is backwards - by default Windows (well, VC++ compiler at least)
>>> assumes text lines end CR LF  (decimal values 13, 10).  The default
>>> text mode will convert CR LF to just LF, which you are seeing above -
>>> presumably empty.txt has just a single empty line terminated by CR LF
>>> ??   If you set the stdin mode to binary you should then expect output
>>> "1310".
>> You're right.  The Windows situation is reversed when we deal with
>> stdin.  If I input \r\n, it replaces to \n if in _O_TEXT.  I totally
>> missed that indeed because --- well, it's so confusing.  Thank you.
>> By the way, because I used write() and saw the translations taking
>> place, I conclude the kernel is doing these translations, not the local
>> C library.
>
> On Windows the low level OS APIs for file IO are ReadFile[Ex] and
> WriteFile[Ex].  These do not know about line endings, or whether the 
> files are ANSI/Unicode etc., they just read/write a block of
> data. Functions like read() write() are part of the CRT, and will
> internally end up calling ReadFile/WriteFile or one of their variants.

Interesting info.  Thanks so much.

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ot: on stdin, stdout, stderr and crlf on windows Meredith Montgomery <mmontgomery@levado.to> - 2021-12-04 20:24 -0300
  Re: ot: on stdin, stdout, stderr and crlf on windows Mike Terry <news.dead.person.stones@darjeeling.plus.com> - 2021-12-05 00:01 +0000
  Re: ot: on stdin, stdout, stderr and crlf on windows Mike Terry <news.dead.person.stones@darjeeling.plus.com> - 2021-12-05 00:13 +0000
    Re: ot: on stdin, stdout, stderr and crlf on windows Meredith Montgomery <mmontgomery@levado.to> - 2021-12-04 23:09 -0300
      Re: ot: on stdin, stdout, stderr and crlf on windows Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-12-04 18:27 -0800
      Re: ot: on stdin, stdout, stderr and crlf on windows Mike Terry <news.dead.person.stones@darjeeling.plus.com> - 2021-12-05 03:33 +0000
        Re: ot: on stdin, stdout, stderr and crlf on windows Meredith Montgomery <mmontgomery@levado.to> - 2021-12-05 09:17 -0300
  Re: ot: on stdin, stdout, stderr and crlf on windows Bonita Montero <Bonita.Montero@gmail.com> - 2021-12-05 15:04 +0100
  Re: ot: on stdin, stdout, stderr and crlf on windows Bonita Montero <Bonita.Montero@gmail.com> - 2021-12-05 15:13 +0100
    Re: ot: on stdin, stdout, stderr and crlf on windows John Forkosh <forkosh@panix.com> - 2021-12-06 08:20 +0000
      Re: ot: on stdin, stdout, stderr and crlf on windows Bonita Montero <Bonita.Montero@gmail.com> - 2021-12-06 09:45 +0100
      Re: ot: on stdin, stdout, stderr and crlf on windows Ben Bacarisse <ben.usenet@bsb.me.uk> - 2021-12-06 10:36 +0000
        Re: ot: on stdin, stdout, stderr and crlf on windows Bonita Montero <Bonita.Montero@gmail.com> - 2021-12-06 13:03 +0100
          Re: ot: on stdin, stdout, stderr and crlf on windows Ben Bacarisse <ben.usenet@bsb.me.uk> - 2021-12-06 12:34 +0000
            Re: ot: on stdin, stdout, stderr and crlf on windows Manfred <noname@add.invalid> - 2021-12-06 14:38 +0100
              Re: ot: on stdin, stdout, stderr and crlf on windows Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2021-12-06 06:00 -0800
                Re: ot: on stdin, stdout, stderr and crlf on windows Manfred <noname@add.invalid> - 2021-12-06 18:59 +0100
              Re: ot: on stdin, stdout, stderr and crlf on windows Ben Bacarisse <ben.usenet@bsb.me.uk> - 2021-12-06 17:08 +0000
                Re: ot: on stdin, stdout, stderr and crlf on windows scott@slp53.sl.home (Scott Lurndal) - 2021-12-06 17:18 +0000
            Re: ot: on stdin, stdout, stderr and crlf on windows John Forkosh <forkosh@panix.com> - 2021-12-07 01:11 +0000
              Re: ot: on stdin, stdout, stderr and crlf on windows Bart <bc@freeuk.com> - 2021-12-07 09:56 +0000
                Re: ot: on stdin, stdout, stderr and crlf on windows John Forkosh <forkosh@panix.com> - 2021-12-08 08:13 +0000
  Re: ot: on stdin, stdout, stderr and crlf on windows Tim Rentsch <tr.17687@z991.linuxsc.com> - 2021-12-10 01:10 -0800
    Re: ot: on stdin, stdout, stderr and crlf on windows gazelle@shell.xmission.com (Kenny McCormack) - 2021-12-10 11:00 +0000

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