sh-3.2# vim /opt/check_osx_updates.sh

#!/bin/sh
if [ "$#" == 2 ]; then
        WARNING="$1"
        CRITICAL="$2"
        UPDATES="$(softwareupdate -l|egrep '[*]'|wc -l|tr -d ' ')"

        if [ $UPDATES -lt $WARNING ]; then
                echo "OK - $UPDATES updates available for installation"
                exit 0
        elif [ $UPDATES -ge $WARNING -a $UPDATES -lt $CRITICAL ]; then
                echo "WARNING - $UPDATES updates available for installation"
                exit 1
        else
                echo "CRITICAL - $UPDATES updates available for installation"
                exit 2
        fi
else
        echo ""
        echo "USAGE:    ./check_osx_updates.sh WARNING CRITICAL"
        echo "EXAMPLE:  ./check_osx_updates.sh 1 5"
        echo ""
        echo "2012 By Christian Stankowic - info at stankowic hiphen development dot net"
fi

sh-3.2# /opt/check_osx_updates.sh 1 5
WARNING - 1 updates available for installation

sh-3.2# /opt/check_osx_updates.sh 

USAGE:    ./check_osx_updates.sh WARNING CRITICAL
EXAMPLE:  ./check_osx_updates.sh 1 5

2012 By Christian Stankowic - info at stankowic hiphen development dot net