Which is the difference between S0 and T0 in /etc/inittab?

Bengt T

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Dec 4, 2008, 3:32:47 PM12/4/08

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In some cases I find "S0:12345:respawn agetty -L 9600 tty S0 vt102"
and in other cases ""T0:12345:respawn..." in rows of /etc/inittab
file.

Can anyone explain the difference between "S..." and T..." please?

Unruh

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Dec 4, 2008, 4:43:49 PM12/4/08

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Bengt T <bengt_t...@hotmail.com> writes:

The first item on the line is an arbitrary name for that line called the
id.

man inittab
id is a unique sequence of 1-4 characters which identifies an entry
in inittab (for versions of sysvinit compiled with the old libc5
(< 5.2.18) or a.out libraries the limit is 2 characters).
Note: traditionally, for getty and other login processes,
the value of the id field is kept the same as the suffix of the cor-
responding tty, e.g. 1 for tty1. Some ancient login accounting
programs might expect this, though I can't think of any.

Lew Pitcher

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Dec 4, 2008, 4:50:44 PM12/4/08

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On December 4, 2008 15:32, in alt.os.linux, Bengt T
(bengt_t...@hotmail.com) wrote:

There's no real difference - the "S0" and "T0" values are just labels, and
have no intrinsic meaning.

The rules (more or less) are that these labels should be unique, and should
in some way reflect the inittab entry. For instance, your "S0" entry
corresponds to a getty on the "S0" (ttyS0) device. Your "T0" entry may
correspond to a getty on the tty0 device.

In my (Slackware 12.0) /etc/inittab, I have
s1:12345:respawn:/sbin/agetty -L ttyS0 9600 vt100
s2:12345:respawn:/sbin/agetty -L ttyS1 9600 vt100
and
c1:1235:respawn:/sbin/agetty 38400 tty1 linux
c2:1235:respawn:/sbin/agetty 38400 tty2 linux
along with
ca::ctrlaltdel:/sbin/shutdown -t5 -r now
and
x1:4:respawn:/etc/rc.d/rc.4

HTH

--
Lew Pitcher

Master Codewright & JOAT-in-training | Registered Linux User #112576
http://pitcher.digitalfreehold.ca/ | GPG public key available by request
---------- Slackware - Because I know what I'm doing. ------

Bengt T

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Dec 5, 2008, 3:27:10 AM12/5/08

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On 4 Dec, 22:50, Lew Pitcher <lpitc...@teksavvy.com> wrote:
> On December 4, 2008 15:32, in alt.os.linux, Bengt T
>

> (bengt_tornqv...@hotmail.com) wrote:
> > In some cases I find "S0:12345:respawn agetty -L 9600 tty S0 vt102"
> > and in other cases ""T0:12345:respawn..." in rows of /etc/inittab
> > file.
>
> > Can anyone explain the difference between "S..." and T..." please?
>
> There's no real difference - the "S0" and "T0" values are just labels, and
> have no intrinsic meaning.
>
> The rules (more or less) are that these labels should be unique, and should
> in some way reflect the inittab entry. For instance, your "S0" entry
> corresponds to a getty on the "S0" (ttyS0) device. Your "T0" entry may
> correspond to a getty on the tty0 device.
>
> In my (Slackware 12.0) /etc/inittab, I have
> s1:12345:respawn:/sbin/agetty -L ttyS0 9600 vt100
> s2:12345:respawn:/sbin/agetty -L ttyS1 9600 vt100
> and
> c1:1235:respawn:/sbin/agetty 38400 tty1 linux
> c2:1235:respawn:/sbin/agetty 38400 tty2 linux
> along with
> ca::ctrlaltdel:/sbin/shutdown -t5 -r now
> and
> x1:4:respawn:/etc/rc.d/rc.4
>
> HTH
>
> --
> Lew Pitcher
>

> Master Codewright & JOAT-in-training | Registered Linux User #112576http://pitcher.digitalfreehold.ca/ | GPG public key available by request

> ---------- Slackware - Because I know what I'm doing. ------

Thanks for clarifying answers.

/Bengt