Ubuntu Manpage: telinit - change system runlevel

Provided by: upstart_1.12.1-0ubuntu4.2_amd64

NAME

       telinit - change system runlevel

SYNOPSIS

       telinit [OPTION]...  RUNLEVEL

DESCRIPTION

telinit may be used to change the system runlevel.

The RUNLEVEL argument should be one of the multi-user runlevels 2-5, 0 to halt the system, 6 to reboot
the system or 1 to bring the system down into single-user mode.

Normally you would use the shutdown(8) tool to halt or reboot the system, or to bring it down to single-
user mode.

RUNLEVEL may also be S or s which will place the system directly into single-user mode without actually
stopping processes first, you probably won't want that.

The runlevel is changed by emitting the runlevel(7) event, which includes the new runlevel in the
RUNLEVEL environment variable as well as the previous runlevel (obtained from the environment or from
/var/run/utmp) in the PREVLEVEL variable.

telinit will write the new runlevel to /var/run/utmp and append a new entry to /var/log/wtmp.

Other commands
telinit may be also used to send basic commands to the init(8) daemon for compatibility with System V.
These are:

Q or q to request that init(8) reload its configuration. This is rarely necessary since Upstart watches
its configuration with inotify(7) and is deprecated by the initctl(8) reload-configuration
command.

U or u to request that the init(8) daemon re-execute itself. This is necessary when upgrading the
Upstart init(8) daemon itself or any of its dependent system libraries to ensure disks can be
unmounted cleanly on shutdown.

Note that if the init daemon is not Upstart, this option will have no effect on the running
init(8) daemon.

OPTIONS

       -e KEY=VALUE
              This specifies an additional environment variable to be included in the event along with  RUNLEVEL
              and PREVLEVEL.

ENVIRONMENT

       RUNLEVEL
              telinit  will  read  the  current  runlevel from this environment variable if set in preference to
              reading from /var/run/utmp

FILES

       /var/run/utmp
              Where the current runlevel will be read from;  this  file  will  also  be  updated  with  the  new
              runlevel.

       /var/log/wtmp
              A new runlevel record will be appended to this file for the new runlevel.

NOTES

       The Upstart init(8) daemon does not keep track of runlevels itself, instead they are implemented entirely
       by its userspace tools.

       See runlevel(7) for more details.

AUTHOR

       Written by Scott James Remnant <scott@netsplit.com>

REPORTING BUGS

       Report bugs at <https://launchpad.net/upstart/+bugs>

COPYRIGHT

       Copyright © 2009 Canonical Ltd.
       This  is  free  software;  see  the  source  for  copying conditions.  There is NO warranty; not even for
       MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.