bash script skeleton to help with the basics (whatever that means)

script-skel.sh

 #!/usr/bin/env bash
############################
############################
############################
# Script Skeleton
# does nothing
# copy it and change it
# its supposed to be a starting
# point for your own scripts
############################
############################
############################
############################

MYPIDFILE="/tmp/${0##*/}.pid"
LOGFILE="${0##*/}.log"
ALARMALIAS="basis"


main()
{
is_interactive
############################
logit "Put Your Code Here"
sleep 10
############################
}


############################
# put your functions here
############################

############################
############################
############################
############################
####### STANDARD FUNCTIONS #
############################
############################
############################
############################

logit() # Provide Standard Logging of Messages
{
 echo  "`date '+%b %e %X'` - Node \"`hostname`\": $*"
}

mail_alarm()
{
 echo  "`date '+%b %e %X'` - Node \"`hostname`\": $*" | mailx -s"${0##*/} ALARM" $ALARMALIAS
}


is_interactive()
{
if /usr/bin/env tty > /dev/null
then
        logit "Not running in background putting messages to standard output."
else
        LOGDIR=$(dirname ${LOGFILE})
        if [ ! -d ${LOGDIR} ]
        then
                 mkdir -p ${LOGDIR}
        fi
        exec 1>>$LOGFILE
        exec 2>>$LOGFILE
fi
}

is_up()
{
HOST=$1
logit Checking to see if $1 is UP
if /usr/sbin/ping $HOST -n 5 | /usr/bin/grep -q "100% packet loss"
then
        logit $1 is DOWN
        return 1
else
        logit $1 is UP
        return 0
fi
}


trap 'rm -f "$MYPIDFILE;exit 2" >/dev/null 2>&1' 1 2 3 13 15
MYPID=$$
echo  $MYPID >> $MYPIDFILE
read INPUTPID < $MYPIDFILE
if [[ "$INPUTPID" != "$MYPID" ]] && ps -fp $INPUTPID 1>/dev/null 2>&1 && ps -fp $INPUTPID | grep -q ${0##*/}
then
        echo "Already Running on PID $INPUTPID"
        mail_alarm  It seems that this script is already running on PID $INPUTPID, I have quit to avoid a conflict, maybe I should be run less often, or the
re is another problem.
else
        main
        rm -f $MYPIDFILE
fi