Path: utzoo!attcan!uunet!husc6!mailrus!ukma!gatech!ulysses!hector!eric
From: eric@hector.UUCP (Eric Lavitsky)
Newsgroups: comp.sys.amiga
Subject: Re: DCRON
Message-ID: <11038@ulysses.homer.nj.att.com>
Date: 23 Dec 88 20:18:19 GMT
References: <8812230336.AA06015@postgres.Berkeley.EDU> <1176@dukeac.UUCP>
Sender: netnews@ulysses.homer.nj.att.com
Reply-To: eric@hector.UUCP (Eric Lavitsky)
Organization: AT&T Bell Laboratories
Lines: 33

In article <1176@dukeac.UUCP> rsb@dukeac.UUCP (R. Scott Bartlett) writes:
>In article <8812230336.AA06015@postgres.Berkeley.EDU> dillon@POSTGRES.BERKELEY.EDU (Matt Dillon) writes:
>	This doesn't allow one to modify the crontab file and expect cron to
>pick up on the changes immediately (well, a minute later).  With DCRON, if you
>modify the crontab, DCRON won't realize the change untill it has to do something
>from the old crontab.  I don't mind AmiCron polling the disk every minute at
>all; in fact, i use this feature to my advantage to know when the HD buffers
>have been flushed so that i can reboot (but that's beside the point).
>
>>(A further refinement
>>would be to read in the file into memory and not scan it at all from disk
>>unless it was modified, but unless you do something every minute the extra
>>memory taken up may not be worth it).
>I think that this might be worth it, in some form or another.

The easy way to do this is as follows:

	If the "cron" is run a second time, have it send a signal to the
	cron that is already running and then exit. This signal will tell the 
	running copy to read the table again.

So, you make a change to the table and run cron again. This simply signals the 
cron which is already running and then exits. DropCloth worked in a similiar 
fashion to kill itself if it found it was already running. This eliminates
the need for seperate commands or switches to do this sort of stuff...

-Eric

ARPA:	eric@topaz.rutgers.edu or eric@ulysses.att.com
UUCP:	{att,ucbvax}!ulysses!eric or {wherever!}rutgers!topaz!eric
SNAIL:	34 Maplehurst Ln, Piscataway, NJ 08854

"To err is human; To really f*ck up requires the root password."