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Re: Rotation

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On 05/01/2016 14:37, Kaz Kylheku wrote:
> On 2016-01-05, BartC <bc@freeuk.com> wrote:
>> On 05/01/2016 04:59, Kaz Kylheku wrote:
>>

>>> Use the :quit command or type Ctrl-D on empty line to exit.
>>
>> That's interesting. I got reprimanded by Richard Heathfield in c.l.c
>> last year for saying that you type Ctrl-D at the 'start' of a line. He
>> said that as the line doesn't yet exist, you can't have the start of it.
>>
>> I wonder if talking about an 'empty' line is any different? He said
>> Ctrl-D is something you type /after/ the previous line is completed.

> In the case of canonical Unix TTY input, Ctrl-D (or whatever character
> is configured for that role) just means "cause the read system call to
> bail immediately, returning whatever characters have been accumulated
> into the caller's buffer already".
>
> If this occurs when no characters have been accumulated, then read
> returns 0, which looks like end-of-file. Indeed, no line of
> input is obtained, since no input is obtained at all.
> That doesn't mean that there never existed a line at all! The TTY user
> can edit the input line, then backspace over it and issue Ctrl-D.

Yes. Or a possible new line existed in the mind of the user, who then 
decides to type Ctrl-D first.

(A bit like changing your mind about going for a drive at the start of a 
proposed trip. The decision is determined by something other than the 
simple fact of finishing the previous trip or completing the previous 
line. And there might not have been a previous line!)

-- 
Bartc

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Rotation Paul <pepstein5@gmail.com> - 2016-01-04 09:25 -0800
  Re: Rotation David Brown <david.brown@hesbynett.no> - 2016-01-04 23:51 +0100
  Re: Rotation BartC <bc@freeuk.com> - 2016-01-05 01:24 +0000
    Re: Rotation Kaz Kylheku <kaz@kylheku.com> - 2016-01-05 04:59 +0000
      Re: Rotation BartC <bc@freeuk.com> - 2016-01-05 12:22 +0000
      Re: Rotation BartC <bc@freeuk.com> - 2016-01-05 12:55 +0000
        Re: Rotation Kaz Kylheku <kaz@kylheku.com> - 2016-01-05 14:37 +0000
          Re: Rotation BartC <bc@freeuk.com> - 2016-01-05 18:48 +0000
  Re: Rotation Melzzzzz <mel@zzzzz.com> - 2016-01-05 09:13 +0100

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