Chapter 9. The Operating System

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in the script. If there are more than one daemon to start, the output should look like this:

echo  n "Starting remote file system services:"

echo  n " nfsd"; start stop daemon   start   quiet nfsd

echo  n " mountd"; start stop daemon   start   quiet mountd

echo  n " ugidd"; start stop daemon   start   quiet ugidd

echo "."

This makes it possible for the user to see what is happening and when the final daemon

has been started. Care should be taken in the placement of white spaces: in the example

above the system administrators can easily comment out a line if they don't want to start

a specific daemon, while the displayed message still looks good.

  When a system parameter is being set

If you have to set up different system parameters during the system boot, you should use

this format:

Setting

parameter

to "

value

".

You can use a statement such as the following to get the quotes right:

echo "Setting DNS domainname to \"$domainname\"."

Note that the same symbol (

) is used for the left and right quotation marks. A grave

accent (

`

) is not a quote character; neither is an apostrophe (

'

).

  When a daemon is stopped or restarted

When you stop or restart a daemon, you should issue a message identical to the startup

message, except that

Starting

is replaced with

Stopping

or

Restarting

respec 

tively.

For example, stopping the printer daemon will like like this:

Stopping printer spooler: lpd.

  When something is executed

There are several examples where you have to run a program at system startup or shut 

down to perform a specific task, for example, setting the system's clock using

netdate

or killing all processes when the system shuts down. Your message should look like this:

Doing something very useful...done.

You should print the

done.

immediately after the job has been completed, so that the

user is informed why they have to wait. You can get this behavior by saying

echo  n "Doing something very useful..."

do_something

echo "done."