Re: Out of ptys

Richard B. Johnson (root@chaos.analogic.com)
Mon, 17 Aug 1998 16:16:07 -0400 (EDT)


On 17 Aug 1998, H. Peter Anvin wrote:

> Followup to: <Pine.LNX.3.95.980817104046.3228A-100000@chaos.analogic.com>
> By author: "Richard B. Johnson" <root@chaos.analogic.com>
> In newsgroup: linux.dev.kernel
> >
> > open("/dev/ptyp1", O_RDWR) = -1 EIO (I/O error)
> > open("/dev/ptyp2", O_RDWR) = 3
> >
> > ioctl(1, TCGETS, 0xbffff1dc) = -1 EINVAL (Invalid argument)
> > ioctl(2, TCGETS, 0xbffff1d0) = -1 EINVAL (Invalid argument)
> >
> > These are invalid because the first 2 opens failed. We don't have
> > fds 1 and 2, only 0 and 3. (3 was the pty).
> >
>
> No, they are invalid because you don't have a stdout and stderr.
> open() doesn't work the way you seem to think here.
>

Well there was never a dup() of any kind, so there could not be a fd
for stdout or stderr. I can see from the source that the idea was
to open these devices until one could be found that did not fail.

> >
> > open("/dev/tty", O_RDWR) = -1 ENXIO (No such device or address)
> >
>
> ENXIO on /dev/tty means you don't have a current tty. From the trace
> I suspect you have your /dev/ptyp*'s set up properly but your
> /dev/ttyp*'s are broken.
>
>

Well this is what `MAKEDEV generic` set up.

ttyp0: character special (3/0)
ttyp1: character special (3/1)
ttyp2: character special (3/2)
ttyp3: character special (3/3)
ttyp4: character special (3/4)
ttyp5: character special (3/5)
ttyp6: character special (3/6)
ttyp7: character special (3/7)
ttyp8: character special (3/8)
ttyp9: character special (3/9)
ttypa: character special (3/10)
ttypb: character special (3/11)
ttypc: character special (3/12)
ttypd: character special (3/13)
ttype: character special (3/14)
ttypf: character special (3/15)

Cheers,
Dick Johnson
***** FILE SYSTEM WAS MODIFIED *****
Penguin : Linux version 2.1.115 on an i586 machine (66.15 BogoMips).
Warning : It's hard to remain at the trailing edge of technology.

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu
Please read the FAQ at http://www.altern.org/andrebalsa/doc/lkml-faq.html