Monitor user time and memory usage of a process

prockmon

#!/bin/bash

if [[ $# < 2 ]];then
    echo 'need two parameters: $0 <interval> <pid>'
    exit 1;
fi

INTERVAL=$1
PID=$2

echo "  time  rss"

while [ $(ps -p $PID|wc -l) -gt 1 ];do
    ps -o time,rss -p $PID | tail -1
    sleep $1
done