Chapter 9. The Operating System

68

A package should register its initscript services using

update rc.d

before it tries to invoke

them using

invoke rc.d

. Invocation of unregistered services may fail.

For more information about using

invoke rc.d

,

please consult its man page

invoke rc.d(8)

.

9.3.4 Boot time initialization

There used to be another directory,

/etc/rc.boot

, which contained scripts which were run

once per machine boot. This has been deprecated in favour of links from

/etc/rcS.d

to files

in

/etc/init.d

as described in `Introduction' on page

64

. Packages must not place files in

/etc/rc.boot

.

9.3.5 Example

The

bind

DNS (name server) package wants to make sure that the name server is running

in multiuser runlevels, and is properly shut down with the system. It puts a script in

/etc

/init.d

, naming the script appropriately

bind

. As you can see, the script interprets the

argument

reload

to send the name server a

HUP

signal (causing it to reload its configuration);

this way the system administrator can say

/etc/init.d/bind reload

to reload the name

server. The script has one configurable value, which can be used to pass parameters to the

named program at startup; this value is read from

/etc/default/bind

(see below).

#!/bin/sh

#

# Original version by Robert Leslie

# , edited by iwj and cs

test  x /usr/sbin/named || exit 0

# Source defaults file.

PARAMS=''

if [  f /etc/default/bind ]; then

. /etc/default/bind

fi

case "$1" in

start)

echo  n "Starting domain name service: named"

start stop daemon   start   quiet   exec /usr/sbin/named \

   $PARAMS

echo "."

;;

stop)