Question: I have created a script to start a server (my first question). Now I want it to run on the system boot and start the defined server. What should I do to get this done? 

My findings tell me put this file in the `/etc/init.d` location, and it will execute when the system will boot. But I am not able to understand how the first argument on the startup will be `start`? Is this predefined somewhere to use `start` as `$1`? If I want to have a case `startall` that will start all the servers in the script, then what are the options I can manage?

My script is like this:

```
#!/bin/bash

case "$1" in
start)
     start
    ;;
stop)
    stop
    ;;

restart)
    $0 stop
    $0 start
    ;;
*)
    echo "usage: $0 (start|stop|restart)"
;;
esac

```

Answer: 
You don't have to --- and shouldn't --- create files in `/etc/rc.d/rcN.d/`; what you should do instead is put a comment in your init script reading

```
# chkconfig NNN A B

```

where `NNN` is the set of run-levels in which you want the script active (e.g., `345` if it's active in runlevels `3`, `4`, and `5`), and `A` and `B` are the start and stop priorities. Then `chkconfig --add foo` (assuming your script is named `foo`) will create the files in `/etc/rc.d/rcN.d/` with the appropriate names.

You can then use `service foo bar` to send the `bar` message to your script (e.g., `start`, `stop`, whatever -- that's where your `$1` comes from).
The $1 is the command line argument that is passed to your script, it is one of start, stop or restart. In [openSUSE](http://en.wikipedia.org/wiki/OpenSUSE), I don't remember having an option to pass other arguments into the script when useing the runlevel editor thingy, so I think that these are probably the only ones you should use.

I don't use [CentOS](http://en.wikipedia.org/wiki/CentOS) myself, but it seems that the program to control what is started at which runlevel is [ntsysv](http://centos.org/modules/newbb/viewtopic.php?viewmode=flat&order=ASC&topic_id=12486&forum=37).