Watch VmRSS

watch-rss.bash

#!/bin/bash

usage_exit() {
    echo >&2 "Usage: ${0##*/} [-n interval] pid"
    exit $1
}

interval=1

while getopts 'hn:' OPT; do
    case "${OPT}" in
        h)
            usage_exit
            ;;
        n)
            if ! [[ ${OPTARG} =~ ^[.0-9]*$ ]]; then
                usage_exit 1
            fi
            interval=${OPTARG}
            ;;
        \?)
            usage_exit 1
            ;;
    esac
done
shift $((OPTIND - 1))

pid=$1
if ! [[ ${pid} =~ ^[1-9][0-9]*$ ]]; then
    usage_exit 1
fi

while true; do
    rss=$(ps -o rss= -p "${pid}")
    [[ $? -eq 0 ]] || exit 0
    printf "%s  % 9d kB\n" "$(date +'%F %T')" "${rss}"
    sleep "${interval}"
done