http:///topic.blg?tuid=2995&tid=599668在Liux或BSD下，Crontab可以实现以秒运行程序的。
格式如下：
1 minute 1
1,5 minutes 1 and 5
* any minute
*/5 any minute that is divisible by 5
1:2 second 2 of minute 1
1:2,5:10 second 2 of minute 1 and second 10 of minute 5
*:3 second 3 of any minute
*:*/5 any second that is divisible by 5
只是设置分钟那里跟平时的不大一样，其他部分一样。
