crontab update

Ed Falk falk at peregrine.Sun.COM
Thu Mar 1 18:22:57 AEST 1990


In article <EMV.90Feb28121501 at duby.math.lsa.umich.edu> emv at math.lsa.umich.edu (Edward Vielmetti) writes:
>
>This is OK but -- I have a bunch of diskless machines with their
>crontab files all mounted via NFS from a server.  To update the whole
>batch I need to log in to every machine and run 'crontab' -- if
>I could automate the procedure somewhat I'd like to.

Why don't you make all the /usr/spool/cron/crontabs/root files
symlinks to /usr/lib/crontab (which you create)?


>crontab doesn't communicate with signals at least in SunOS 4.x.
>It writes something to /var/spool/cron/FIFO, but what?  Here's
>the trace I got:
>	open ("/var/spool/cron/FIFO", 05, 037777777776) = 3
>	write (3, "".., 26) = 26
>strings on crontab(1) doesn't help, anyone with sources care
>to decode this?

I wondered about that.  I can edit my crontab at 1410 and set something
to go at 1411, and it always works.  Cron is certainly finding out
about the change right away.

Anyway, if you do an 'ls -F' on /var/spool/cron/FIFO, you'll see that
it's a named pipe, not a regular file.  Clever.

		-ed falk, sun microsystems
		 sun!falk, falk at sun.com
		 card-carrying ACLU member.



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