So I did:

bash-2.02$ perl -e '{warn scalar localtime,$/;sleep 60;redo}'
Wed Mar 21 10:27:12 2001
Wed Mar 21 10:28:12 2001
Wed Mar 21 10:29:12 2001
^C
[download]

Well, I looked at that and said to my self, "That would look nicer if the seconds field was just 00." So I tried:

bash-2.02$ perl -e 'while(time%60){}{warn scalar localtime,$/;sleep 60
+;redo}'
Wed Mar 21 10:39:00 2001
Wed Mar 21 10:39:59 2001
Wed Mar 21 10:40:59 2001
Wed Mar 21 10:41:59 2001
^C
[download]

That through me for a bit of a loop, and I thought about it and remembered that sleep is imprecise.
From Camel2: On some systems, the function sleeps till the "top of the second"
Ok, I can handle that, but then the "top of the second" ought to be 60-61 seconds, right? Nope.
From sleep: On some older systems, it may sleep up to a full second less than what you requested
Well, I can work with that, so after playing with select, I landed on:

bash-2.02$ perl -e '{while(time%60){}warn scalar localtime,$/;sleep 59
+;redo}'
Wed Mar 21 10:58:00 2001
Wed Mar 21 10:59:00 2001
Wed Mar 21 11:00:00 2001
Wed Mar 21 11:01:00 2001
^C
[download]

But what I don't understand, and perhaps someone can enlighten me, is why "top of the second" would round down like that, instead of up. Either I don't understand the phrase, or on some older systems it is just a different behaviour. The system, by the way, is running SunOS 5.7. Also, why didn't it drift before I added the initialization? I thought that maybe the initialization was putting it on the edge, so I added a select statement to pause it for an additional tenth of a second, and ten minutes later it had drifted off again. This leads me to think that the system clock it-self might be at fault. Ideas? Insights?

---

^*Why would you want keep alive packets? Why would a system time you out? Well actually, I'm behind a firewall that kills any tcp session where no data is passed for a couple of minutes (ie, the sequence numbers don't change). Not nice when you go to ask someone a question and come back to find that you have been disconnect. Technically, any amount of data would prevent the disconnect, but the time was just more esthetically pleasing.