please explain

[Paul Howarth]

Deepak Oberoi wrote:
> can some one help me understand these few lines of
> code please?
> ::::::::::::
> ::::::::::::
> ::::::::::::
> make all -C /etc/mail -s

Run "make" silently in directory /etc/mail (see "man make")

> 35: else
> 36: for i in virtusertable access domaintable
> mailertable ; do

For each of the files ( virtusertable access domaintable mailertable )

> 37: if [ -f /etc/mail/$i ] ; then

If the file exists in directory /etc/mail

> 38: makemap hash /etc/mail/$i < /etc/mail/$i

Use the makemap program (see "man makemap") to "compile" the text file into a 
database format that sendmail can use directly.

> 39: fi
> 40: done
> 41: fi

End the if and loop constructs.

> 42: /usr/bin/newaliases > /dev/null 2>&1

Rebuild the aliases database from the text file.

> 43: daemon /usr/sbin/sendmail $([ "x$DAEMON" = xyes ]
> && echo -bd) \

This initscript has previously included the file /etc/sysconfig/sendmail, 
which may have set the DAEMON variable. If it did, start sendmail with 
parameter "-bd" (have sendmail listen for incoming SMTP mail connections). 
"daemon" is a function defined in /etc/rc.d/init.d/functions to start programs 
nicely in the background.

> 44: $([ -n "$QUEUE" ] && echo -q$QUEUE)

If the QUEUE variable is set, add -q$QUEUE to the parameters used when 
starting sendmail. Typically used to have sendmail process the mail queue 
every 20 or 30 minutes.

> $SENDMAIL_OPTARG

Add any optional parameters required.

> 45: RETVAL=$?

Set the variable RETVAL to the exit status of the "daemon" command. If the 
result is zero, all is well.

> 46: echo
> 47: [ $RETVAL -eq 0 ] && touch
> /var/lock/subsys/sendmail

If sendmail appears to have started properly, create an empty file 
/var/lock/subsys/sendmail to indicate that sendmail is running.

Paul.