CORE-POS/IS4C

#!/bin/bash
#
# posdriver-ssd2 Startup script for ssd
#
# chkconfig: - 80 20
# description: runs ssd scale driver as a daemon

# --COMMENTS - - - - - - - - - - - - - - - - - - - - - - - - -
#
# 16May12 EL Remove some of the superseded, commented code.
# 13May12 EL Change name to posdriver2-ssd to not conflict with upstream version.
#  8Apr12 EL Get PID of the ssd process after startup and record as ssdp.pid.
#            Add killing of the process to "stop"
#            Add "clean" option to rm ssdp.pid if process is gone in
#               order to allow start.
#            Add "status" option to show pid and ssdp.pid.
#            ? Is something needed to prevent multiple starts,
#               i.e. check if daemon already running before starting another?
#  7Apr12 EL In "start" change the location of the driver.
#            What do "success" and "failure" do? Added functions for them.
#            In start(), changed initial test from -z to ! -f

# --CONSTANTS - - - - - - - - - - - - - - - - - - - - - - - - -

NAME=posdriver2-ssd
DHOME=/var/run/${NAME}
KILL=/bin/kill

# --FUNCTIONS - - - - - - - - - - - - - - - - - - - - - - - - -

function noop()
{
    NOOP=""
}
function failure()
{
    echo "failure";
}
function success()
{
    echo "success";
}

# Make the directory to contain the posdriver2-ssd pid and log
#  if it doesn't exist, which it doesn't to begin with.
#  It apparently does not survive reboot.
function makelogdir ()
{
    if [ ! -d $DHOME ]; then
        #echo "Would make: $DHOME";
        /usr/bin/sudo mkdir -p $DHOME
        RETVAL=$?
        if [ "$RETVAL" = "0" ]; then
            echo "Made: $DHOME";
            success;
        else
            echo "Could not make: ${DHOME} : $RETVAL";
            failure;
            exit 1;
        fi
    else
        echo "${DHOME} (already) exists."
        #echo "${DHOME} does not need to be created."
    fi

# makelogdir
}

start(){
    echo "Starting $NAME"
    if [ ! -f ${DHOME}/ssdp.pid ]; then

        # Make the directory where the PID and log files are kept if it
        #  doesn't exist.
        makelogdir

        # Start the driver in the background as user nobody.
        /usr/bin/sudo -u nobody /var/www/IS4C/pos/is4c-nf/scale-drivers/drivers/rs232/ssd &> ${DHOME}/ssd.log &
        # Store the PID of the startup process.
        MYPID=$!
        echo $MYPID > ${DHOME}/ssd.pid
        RETVAL=$?
        if [ "$RETVAL" = "0" ]; then
            echo "Started: $NAME as PID: ${MYPID}"
            # See if the ssd process is actually running.
            #  It is not the same pid as the startup returned,
            #   and the startup process is no longer alive.
            # Apparently takes a bit of time for the daemon to start, or be known to ps.
            sleep 2
            MYPIDP=`/bin/ps --no-headers -C ssd -o pid=`
            if [ "$MYPIDP" ] ; then
                echo "Running: $NAME as PIDP: ${MYPIDP}"
                echo "$MYPIDP" > ${DHOME}/ssdp.pid
                success;
            else
                echo "$NAME PIDP: >${MYPIDP}< is not running."
                failure;
            fi
        else
            echo "Could not start: ${NAME} : $RETVAL"
            failure;
        fi
    else
        echo "$NAME is already running"
        failure;
    fi
    echo

# start
}

stop(){
    echo "Stopping $NAME"
    # Look for the pid of the actual daemon, not the startup process.
    if [ -f ${DHOME}/ssdp.pid ]; then
        MYPIDP=`cat ${DHOME}/ssdp.pid`
        # This works but reports "No such process" - why?
        #kill $MYPIDP
        $KILL `cat ${DHOME}/ssdp.pid`
        RETVAL=$?
        # In bash, quoting and " = " vs. -eq don't seem to matter.
        if [ "$RETVAL" = "0" ]; then
            # EL: Added rm.
            rm ${DHOME}/ssdp.pid
            RETVAL=$?
            if [ "$RETVAL" = "0" ]; then
                echo "Killed ${MYPIDP} and rm'd ${DHOME}/ssdp.pid"
                success;
            else
                echo "Killed ${MYPIDP} but could not rm ${DHOME}/ssdp.pid"
                failure;
            fi
        else
            echo "Could not kill ${MYPIDP} because: >$RETVAL<"
            failure;
        fi
    else
        echo "$NAME is not running"
    fi
    echo
# stop
}

clean(){

    echo "Cleaning $NAME"
    MYPIDP=`/bin/ps --no-headers -C ssd -o pid=`
    if [ -z "$MYPIDP" ] ; then
        if [ -f ${DHOME}/ssdp.pid ]; then
                rm ${DHOME}/ssdp.pid
                RETVAL=$?
                if [ "$RETVAL" = "0" ]; then
                    echo "ssd is not running. rm'd ${DHOME}/ssdp.pid"
                    noop;
                else
                    echo "Could not rm ${DHOME}/ssdp.pid"
                    echo "Since ssd is not running normal start should be possible."
                    noop;
                fi
        else
            echo "ssd is not running. No ${DHOME}/ssdp.pid to rm."
        fi
    else
        printf "The ssd is still running >${MYPIDP}< so did not rm ${DHOME}/ssdp.pid which "
        if [ -f ${DHOME}/ssdp.pid ]; then
            printf "does"
        else
            printf "does not"
        fi
        echo " exist."
        noop;
    fi

# clean
}

status(){

    echo "Status of $NAME"

    MYPIDP=`/bin/ps --no-headers -C ssd -o pid=`
    if [ "$MYPIDP" ] ; then
        echo "The ssd is running as >${MYPIDP}<"
    else
        echo "The ssd is not running."
    fi
    makelogdir;
    if [ -f ${DHOME}/ssdp.pid ]; then
        MYPIDF=`cat ${DHOME}/ssdp.pid`
        printf "${DHOME}/ssdp.pid exists and contains: >${MYPIDF}<\n"
        if [ "$MYPIDP" != "$MYPIDF" ] ; then
            printf "*** Alert: They don't agree!\n";
        fi
    else
        echo "${DHOME}/ssdp.pid does not exist."
    fi

# status
}

case "$1" in
    start)
        start
        ;;
    stop)
        stop
        ;;
    restart)
        stop
        sleep 2
        start
        ;;    
    clean)
        clean
        ;;
    status)
        status
        ;;
    *)
        echo $"Usage: $NAME {start|stop|restart|clean|status}"
        exit 1
esac

exit 0