Bash script to check for Java processes that have lived longer than their maximum expected run time

check_stuck_java.sh

#/bin/sh

# number of ticks since boot
UPTIME=$(awk '{print $1}' /proc/uptime | xargs printf '%.0f')
WARNINGS=
FOUND=0

for pid in $(pgrep -f java)
do
    # get elapsed jiffies in seconds for each java process
    STAT=$(cat /proc/$pid/stat)
    STARTTIME=$(getconf CLK_TCK | xargs expr $(awk '{print $22}' /proc/$pid/stat) /)
    TIME=$(expr $UPTIME - $STARTTIME)
    if [ "$(expr $UPTIME - $STARTTIME)" -gt 7200 ] # 2 hours
    then
        WARNINGS="$WARNINGS\nPID $pid running since $(ps h -p $pid -o lstart)"
        ((FOUND++))
    fi
done

if [ "$FOUND" -gt 0 ]
then
    echo -e "WARNING: $FOUND possibly stuck java processes.\n$WARNINGS"
    exit 1
fi

echo "OK: no stuck java processes."
exit 0