vi ~/.bash_aliases

repeat() {
    n=100
    s=1

    while true; do
        arg=$1
        if [ "$arg" == "-n" ]; then
            n=$2
            shift
            shift
        elif [ "$arg" == "-s" ]; then
            s=$2
            shift
            shift
        else
            break
        fi
    done

    while [ $((n -= 1)) -ge 0 ]; do
        "$@"
        sleep $s
    done
}

	source ~/.bash_aliases

	repeat ls -l
	repeat date
	repeat iostat
	repeat -n 3 curl 'http://www.lianghaijun.com'
	repeat -n 3 -s 300 curl 'http://www.lianghaijun.com'
	repeat -n 3 -s 0.5 sh -c "curl -I -s 'http://www.lianghaijun.com' | head -1"