Re: [avrdude-dev] “Not a typewriter” avrdude err or on Android

[Anton Smirnov]

Okay, thanks for the explanation.

2013/6/10 Joerg Wunsch <address@hidden>

> As Anton Smirnov wrote:
>
> > > Frankly: I don't know.
>
> > Can you say what is required (compile params, flags, etc..) exactly?
> > I think i will have to ask for it from android engineers or smth.
>
> It's the POSIX (“Single UNIX Specification”, SUS) API calls
> tcgetattr()/tcsetattr(), in whatever way they might be implemented.
>
> If it's really just the isatty() call but the actual calls to
> tcsetattr()/tcgetattr() would work, it's certainly safe to must remove
> the isatty() test.  The meaning of “terminal” is not very strictly
> defined in SUS, but if a descriptor returns a failure for isatty() but
> can successfully modified via tcsetattr(), this would for sure be
> somewhat self-contradictional.
>
> OTOH, dropping the isatty() check is safe: when trying to apply the
> serial port operations to a non-tty descriptor, they are supposed to
> fail anyway, so it's not important to check the descriptor for
> belonging to a terminal device beforehand.
>

Okay, since i'm completely in stuck with it i have to try just
comment/remove isatty() check.


>
> > > Btw., there's no real need to pass the descriptor along a socket, you
> > > could as well pass it through a commandline option and just bypass the
> > > open().
>
> > Not sure that's true. AFAIK file descriptor is process-related and it
> means
> > nothing in context of another process
>
> If it follows the UNIX process model, file descriptors inherited
> after a fork() are supposed to be the same, I think.  SUS says
> (in the description of fork()):
>
> “The child process shall have its own copy of the parent's file
> descriptors. Each of the child's file descriptors shall refer to the
> same open file description with the corresponding file descriptor of
> the parent.”
>
> Of course, a foreign descriptor outside of a child process makes no
> sense, but inside a child process, it's supposed to work.  (File
> descriptors are mandated to be small integer numbers, where “small”
> refers to the requirement that each call that returns a new open
> descriptor actually returns the smallest number that is not currently
> open for that particular process.)
>
> (If it doesn't follow the UNIX process model, things are of course
> different.)
>

Well, now the question is "does android (linux) follow UNIX Process model
or not?".
Do you think i have to just pass file descriptor as int and just skip using
socket?


> --
> cheers, Joerg               .-.-.   --... ...--   -.. .  DL8DTL
>
> http://www.sax.de/~joerg/
> Never trust an operating system you don't have sources for. ;-)
>
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