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runlevel(8) [linux man page]

runlevel(8)						      System Manager's Manual						       runlevel(8)

NAME

       runlevel - output previous and current runlevel

SYNOPSIS

       runlevel [OPTION]...  [UTMP]

DESCRIPTION

       runlevel  reads	the  system UTMP file, which defaults to /var/run/utmp when no alternate filename is given, to locate the most recent run-
       level record.

       The previous and current runlevel from that record are output separated by a single space.  If there is no previous runlevel in the record,
       the letter N will be substituted.

       If no runlevel record can be found, runlevel outputs the word unknown and exits with an error.

       During  system  boot,  the  environment variables RUNLEVEL and PREVLEVEL will be set by the init(8) daemon, these come from the runlevel(7)
       event generated by telinit(8) or shutdown(8).

       When these environment variables are set, runlevel will output the values from these instead.  Thus runlevel can be used in rc scripts as a
       replacement for the System-V who(1) -r command.

OPTIONS

       --quiet
	      Does  not  output the current and previous runlevel, nor does it output unknown in the case of error (but it will exit with an error
	      code).

	      This may be used to test for the presence of a runlevel entry, or to check for errors reading from the file.

EXIT STATUS

       runlevel will exit with status 0 if a UTMP record was found, otherwise it will exit with status 1.

ENVIRONMENT

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

       PREVLEVEL
	      runlevel will read the previous runlevel from this environment variable if RUNLEVEL
	       was given, in preference to reading from /var/run/utmp

FILES

       /var/run/utmp
	      Where the current and previous runlevels will be read from.

NOTES

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

       A change of runlevel is signalled by the runlevel(7) event, generated by either the telinit(8) or shutdown(8) tools.  This  event  includes
       the  new  runlevel  in  the  RUNLEVEL  environment  variable, as well as the previous runlevel (obtained from their own environment or from
       /var/run/utmp) in the PREVLEVEL variable.

       As well as generating the event, both tools write the new runlevel back to /var/run/utmp and append a new entry to /var/log/wtmp.

AUTHOR

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

REPORTING BUGS

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

COPYRIGHT

       Copyright (C) 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 PARTICU-
       LAR PURPOSE.

SEE ALSO

       runlevel(7) init(8) telinit(8) shutdown(8) who(1)

Upstart 							    2009-07-09							       runlevel(8)

Check Out this Related Man Page

telinit(8)						      System Manager's Manual							telinit(8)

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 prob-
       ably 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 not recommended since Upstart is currently unable to preserve its
	      state, but is necessary when upgrading system libraries.

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 (C) 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 PARTICU-
       LAR PURPOSE.

SEE ALSO

       runlevel(7) init(8) initctl(8) shutdown(8) runlevel(8)

Upstart 							    2009-07-09								telinit(8)
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