簡便なSafariとChromeのメモリ使用量の測定方法 ref: http://qiita.com/ikuwow/items/976166b30610f33f4643

file1.txt

$ sh safari_vs_chrome.sh &

file2.txt

$ tail -f safari_vs_chrome.log

file3.txt

2015-04-05 11:04:14 926424 874976
2015-04-05 11:04:15 926372 874972
2015-04-05 11:04:17 926380 874952
2015-04-05 11:04:18 926412 874952
2015-04-05 11:04:19 926456 874952
Date                Safari  Chrome
2015-04-05 11:04:20 926536 874952
2015-04-05 11:04:21 926484 874944
2015-04-05 11:04:22 926628 874960
（以下続く）

safari_vs_chrome.sh

#!/bin/bash

logfile="./safari_vs_chrome.log"

while sleep 1; do

    now=`date +%S`
    surplus=`expr $now % 10`
    if [ $surplus -eq 0 ];then
        echo 'Date                Safari  Chrome' > $logfile
    fi

    echo `date "+%Y-%m-%d %H:%M:%S"` \
    `ps aux | grep Safari | awk '{sum += \$6}END{print sum}'` \
    `ps aux | grep Chrome | awk '{sum += \$6}END{print sum}'` > $logfile
done