Re: [Wrapper-user] run levels

[Leif M. <le...@ta...>]

Arun,
    What are run levels?  Well that is a subject that I could spend all 
night explaining, and
has nothing to do with the Wrapper directly.

    Basicly, the UNIX system operates in various runlevels when it is in 
different states.
For example, when the system normally boots up, it goes into what is 
called "multi user mode",
or run level #2.   Then when the system is shutting down, it goes into 
"halt", level #0, or
"reboot", level #6 runtime level.   If you are having problems with your 
system, you may wish
to boot into a "single user" mode.  This is called run level #1.

    If you look in the rc*.* directories, you will see a list of shell 
scripts that are executed
when ever the system enters a specific run level.  The scripts within 
each directory are
executed in the order specified by their names.

    "Snn_xxx"  means that the "xxx" script will be executed with an 
order of "nn", and be
passed the "start" parameter.

    "Knn_xxx" means that the "xxx" script will be executed with an order 
of "nn" and be
passed the "stop" parameter.

    All of the scripts in run level #2, /etc/rc2.d/, will be executed on 
startup.  And then
all scripts in /etc/rc0.d/ will be executed on shutdown.

    So if you placed a symbolic link to your wrapper script in the 
following 2 directories:
/etc/rc0.d/K20myapp
/etc/rc2.d/S20myapp
Then your "myapp" application would be called with "myapp start" on 
system startup and
then "myapp stop" on system shudown.

    Make sense?

    Here is one site which kind of explains it.  I remember the first 
time I tried to figure
run levels out.  There are not many sites out there which explain it in 
an easy to
understand way.
http://www.pucmmsti.edu.do/materias/fnunez/RUTE_TUT/node35.html

    Please consider donating to the project if you have found this 
information useful.
Answering questions to make it possible for you to do your job takes 
real time.
Donations put me in a great mood and make me look forward to hearing 
from you
again.
http://wrapper.tanukisoftware.org/doc/english/donate.html

Cheers,
Leif

Ramachandra, Arun wrote:

> The help docs for starting the wrapperlistener app at reboot says:
> "We will want our application to be started for all multi-user run 
> levels and stopped for the halt, single-user and reboot runlevels."
>
> I did not quite understand what this means.
> Could anybody please explain? What exactly is meant by a run level?
>
>  -Thanks
>  -Arun
>
>