crontab实现每秒执行

crontab

#!/bin/bash

step=$1

for (( i = 0; i < 600000; i=(i+step) )); do
    date +%Y%m%d‘ ‘%H:%M:%S >>/home/xiluhua/procNum.txt
    printf " "
    ps -ef|grep memcached | grep 11211 >> /home/xiluhua/procNum.txt
    printf "\n" >> /home/xiluhua/procNum.txt
    sleep $step
done