The s6-linux-init-telinit program
s6-linux-init-telinit changes runlevels, i.e. changes the
system state. It is normally invoked as /sbin/telinit or
just init with an argument.
- s6-linux-init-telinit may be called with the same options as
s6-linux-init, but it ignores them all.
- It calls the runleveld
local service with
the rl argument. This local service executes the user-provided
runlevel script, which changes the system state to the state
described by rl.
- As a special case, if rl is 0 or 6,
s6-linux-init-telinit then executes into
s6-linux-init-hpr with the -p
or -r option respectively,
for compatibility with sysvinit's 0 and 6 runlevels
that respectively halt and reboot the machine.
- 100: wrong usage
- 111: system call failed
- Else, s6-linux-init-telinit exits with the same exit code
as the runlevel script called with the rl argument.
- If rl is 0 or 6, in case of success
s6-linux-init-telinit exits 0, but the system shuts down
immediately as it returns.
- Traditional sysvinit only allows integer runlevels, from 0 to 6.
More advanced service managers, like OpenRC or s6-rc, allow the admin to
define alphanumerical runlevels, or states. s6-linux-init-telinit
does not implement policy; it only makes sure the user-provided runlevel
script is called with the rl argument, under a safe and reproducible
environment. The runlevel script can then change the machine state
as chosen by the user - typically by invoking the service manager.
- The 0 and 6 special case has been added because
some legacy programs may assume that calling init 0 and init 6
respectively halt and reboot the system.
- The s6-linux-init-telinit
binary is not meant to be called directly by administrators. Instead, after a
the bin/ subdirectory of the target will contain a telinit
symlink to s6-linux-init-telinit. The bin/ subdirectory
should be copied by the administrator into /sbin for full
interface compatibility with sysvinit.
- When the system is running inside a container (and the -C
option has been given to
s6-linux-init-maker), the runleveld
service is not running, so s6-linux-init-telinit is not
functional and the runlevel script is never invoked.