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]*.

diff --git a/docs/CONTAINER_INTERFACE.md b/docs/CONTAINER_INTERFACE.md
index 9b3e0e56ec846c4e82c5b53267e7b95d833305f2..411bd5873b7b3e78d1d560e4b8aafb61bd12283d 100644 (file)
--- a/docs/CONTAINER_INTERFACE.md
+++ b/docs/CONTAINER_INTERFACE.md
@@ -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.