こんな感じで書いてみました。
デプロイ方法はこちらをご覧ください。
#!/bin/bash -e
##-------------------------------------------------------------------
## File: check_memory_procs
## Author : Yutaka Hiroyama
## Description :
## --
##
## Created : <2015-08-05>
## Updated: Time-stamp: 
##-------------------------------------------------------------------
if [ "$1" = "-w" ] && [ "$2" -gt "0" ] && \
    [ "$3" = "-c" ] && [ "$4" -gt "0" ]; then

    procpattern=${5}

    total=`grep "MemTotal" /proc/meminfo | awk  -F' ' '{print $2}'`
    memVmSize=`ps aux | grep "$procpattern" | grep -v grep | grep -v check_proc_mem.sh | awk '{sum += $6} END {print sum}'`
    per=$((($memVmSize*100)/$total))

    memVmSize=$(($memVmSize/1024))

    if [ "$per" -ge "$4" ]; then
        echo "Memory: CRITICAL - $procpattern using $memVmSize MB ($per %)"
        $(exit 2)
    elif [ "$per" -ge "$2" ]; then
        echo "Memory: WARNING - $procpattern using $memVmSize MB ($per %)"
        $(exit 1)
    else
        echo "Memory: OK - $procpattern using $memVmSize MB ($per %)"
        $(exit 0)
    fi

else
    echo "check_memory_procs v1.0"
    echo ""
    echo "Usage:"
    echo "check_memory_procs -w <warn_%> -c <criti_%> <pattern_proc>"
    echo ""
    echo "Copyright (C) 2015 Yutaka Hiroyama"
    exit
fi