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 runlevel
       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 val-
       ues  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 pre-
       vious  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 PARTICULAR
       PURPOSE.

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



Upstart				  2009-07-09			   runlevel(8)