docs: remove /dev/tty* confusion

The text said /dev/tty* as a whole was the VT subsystem and that VT is
not supported in containers.

But that's not accurate as /dev/tty* will match /dev/tty too and that
one device node is special and is not related to VT: it always points to
the current process own controlling tty, regardless what that is.

hence, rewrite /dev/tty* as /dev/tty[0-9]*.
This commit is contained in:
Lennart Poettering 2022-12-23 18:39:54 +01:00 committed by Luca Boccassi
parent 0941ccae3c
commit 6ae5c39af1

View file

@ -298,9 +298,9 @@ care should be taken to avoid naming conflicts. `systemd` (and in particular
you cannot link them to each other.
4. Do not pretend that the real VTs are available in the container. The VT
subsystem consists of all the devices `/dev/tty*`, `/dev/vcs*`, `/dev/vcsa*`
plus their `sysfs` counterparts. They speak specific `ioctl()`s and
understand specific escape sequences, that other ptys don't understand.
subsystem consists of all the devices `/dev/tty[0-9]*`, `/dev/vcs*`,
`/dev/vcsa*` plus their `sysfs` counterparts. They speak specific `ioctl()`s
and understand specific escape sequences, that other ptys don't understand.
Hence, it is explicitly not OK to mount a pty to `/dev/tty1`, `/dev/tty2`,
`/dev/tty3`. This is explicitly not supported.