What is it? (was Re: Current Run-Level: How can you tell?)

[Wes Peters]

In article <1991Apr25.171617.13505 at ssd.kodak.com>, weimer at garden.ssd.kodak.com (Gary Weimer (253-7796)) writes:
> BSD Unix (?) has three "run levels": Single-user, Multi-user and Halt.
> Usually we say the system is: 
>      in Single-user mode
>      in Multi-user mode
>      Down ( 1/2 :-) )

       ^^^^^ Note that this is the natural state of all computers.  :-)

> System V (?) Unix has many levels:
>      0 == Halt
>      3 == normal Multi-user mode
>      others (this is were it gets brief :-) )

Not quite.  Actually:
	0 = Shutdown
	1 = Single-user (roughly)
	2 = Normal multi-user
	3 = Another multi-user
	4 = ?????
	5 = Enter monitor program, if present
	6 = Halt

Init state 3 is used to run multi-user, but is differentiated from 2 because
all the startup files can check to see what state you're in.  For instance,
you might define 2 to mean 'multiuser with network running' and 3 to mean
'multiuser with network shut off' or something similar.  Getty, which starts
the login process on terminals amongst other things, can tell what init
state you're in also.

Init state 5 goes into the setup program on my brother's 386, as close as
you can get to a 'monitor' program.  I don't have my System V manuals at
hand, or I'd be able to flush this out a little more for you.

	Wes Peters
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