"shutdown now" on F11 as root problems and app crashes in

[Phil Meyer]

On 11/02/2009 11:39 AM, KC8LDO wrote:
> Rick;
>
> I just checked the command line version, using "--help", as you 
> suggested, and the info is there, of course. I wasn't expecting that 
> sort of default behavior. Nothing in the man page that warns about it. 
> Somebody may want to consider adding that tid-bit to the man page. I 
> thought the man pages were the main source of info for various 
> commands etc., looks like it isn't. Guess I'll just have to be more 
> careful. Another day, learn something new.
>
> Thanks;
>
> Leland C. Scott
> KC8LDO
> ----- Original Message ----- From: "Rick Stevens" <ricks at nerd.com>
> To: "KC8LDO" <kc8ldo at arrl.net>; "Community assistance, encouragement, 
> and advice for using Fedora." <fedora-list at redhat.com>
> Sent: Monday, November 02, 2009 1:19 PM
> Subject: Re: "shutdown now" on F11 as root problems and app crashes in
>
>
>> KC8LDO wrote:
>>> Bob;
>>>
>>> I did go back and read it, should have done that first. I did read 
>>> that one of the options the action taken is system dependent, the 
>>> "-h" option. That makes things more interesting.
>>>
>>> I'm sitting here at work, eating lunch, reading the man page, again, 
>>> for the shutdown command using a remote VNC session to my F10 box at 
>>> home. I don't see anything that mentions any sort of default action 
>>> if you fail to supply one of the options to the shutdown command. 
>>> All it says in general at the end of the man page is :
>>>
>>> "When invoked it generates a runlevel event, with an argument 
>>> containing the new runlevel."
>>>
>>> I'll have to look specifically at the one, man page, on the F11 box 
>>> later when I get home. Your comment suggests they are not the same.
>>>
>>> One last comment. If I was not by the local attached console and saw 
>>> what happened, but was working remotely when I issued the "shutdown 
>>> now" command, having the system drop down to a CLI interface, single 
>>> user mode, with the root prompt showing isn't very comforting. Also 
>>> my remote VNC session terminated too. Not my idea of a way to lose 
>>> control of the box and give somebody else the chance to have some 
>>> fun at the "free" root prompt either. Lucky for me this box is on my 
>>> home network where I'm the only one with physical access.
>>
>> "shutdown --help" on both F10 and F11 result in this data:
>>
>> "<snip>
>> The system is brought down into maintenance (single-user) mode by
>> default, you can change this with either the -r or -h option which
>> specify a reboot or system halt respectively.  The -h option can be
>> further modified with -H or -P to specify whether to halt the system, or
>> to power it off afterwards.  The default is left up to the shutdown
>> scripts.
>> </snip>"
>>
>> So it goes to run level 1 or "s" by default.

Just to add confusion to your research, you will find a whole group of 
UNIX/Linux admins that prefer to use the init command to shut down or 
change the state of a system.

These admins, like myself, are SYSV oriented, where the shutdown command 
was a simple shell script that called the init program.

On Fedora, SUSE and other SYSV oriented Linux distros, the old habit of 
using init is supported.

Thus:

# init 0

Goes to power off mode in Linux, and to firmware mode on Solaris.

# init 3

Goes to run level 3.

# init 5

Goes to run level 5, except on Solaris, where it is power off! :)

# init 6

Is the equivalent of typing reboot.

etc etc

Good Luck!