runlevel.8

upstart 事件驱动的Linux启动程序

.TH runlevel 8 "October 2006" "Upstart"
.\"
.SH NAME
runlevel \- output previous and current runlevel
.\"
.SH SYNOPSIS
\fBrunlevel\fR [\fIOPTION\fR]... [\fIUTMP\fR]
.\"
.SH DESCRIPTION
.B runlevel
reads the system
.I utmp
file
.RI "(typically " /var/run/utmp )
to locate the most recent runlevel record, then outputs the previous and
current runlevel from that record to standard output, separated by a single
space.

If there is no previous runlevel in the record, the letter
.I N
will be printed instead.

If no
.I utmp
file exists, or if no runlevel record can be found,
.B runlevel
prints the word
.I unknown
and exits with an error.
.\"
.SH OPTIONS
.TP
.BR --set =\fIRUNLEVEL
Store a new runlevel record in the
.I utmp
file.
.I RUNLEVEL
should be one of 0123456S.

The current runlevel in the output will be
.IR RUNLEVEL ,
the previous runlevel will be the runlevel from the last record or
.I N
.\"
.TP
.B --reboot
Store a record of the time the system was booted in the
.I utmp
file, using the current time.

This will not output anything.
.\"
.SH EXIT STATUS
.B runlevel
will exit with status
.I 0
if a
.I utmp
record was found or written to the file, otherwise it will exit with status
.IR 1 .
.\"
.SH NOTES
This tool is provided for compatibility with the traditional System V
.BR init (8).
Upstart has no notion of runlevels itself, this and the
.BR telinit (8)
tool are provided to emulate their behaviour.
.\"
.SH AUTHOR
Written by Scott James Remnant.
.\"
.SH REPORTING BUGS
Report bugs at https://launchpad.net/products/upstart/+bugs
.\"
.SH COPYRIGHT
Copyright \(co 2006 Canonical Ltd.
.br
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
.\"
.SH SEE ALSO
.BR init (8)
.BR telinit (8)