On Wed 03 Mar 04, 11:56 AM, Samuel N. Merritt <[EMAIL PROTECTED]> said: > On Wed, Mar 03, 2004 at 11:40:24AM -0800, Peter Jay Salzman wrote: > > On Wed 03 Mar 04, 11:28 AM, Jeff Newmiller <[EMAIL PROTECTED]> said: > > > On Wed, 3 Mar 2004, Ken Herron wrote: > > > > > > > --On Wednesday, March 03, 2004 10:11:10 -0800 Peter Jay Salzman > > > > <[EMAIL PROTECTED]> wrote: > > > > > > > > >> > 25 4 * * * root test -e /usr/sbin/anacron || run-parts --report > > > > >> /etc/cron.daily > > > > >> > > > > >> That line will only launch "run-parts" if /usr/sbin/anacron doesn't > > > > >> exist. Does /usr/sbin/anacron exist? > > > > > > > > > > ken, > > > > > > > > > > yeah, it does exist. daily definitely runs. it just runs at a time i > > > > > wasn't expecting. > > > > > > > > My point was that if /usr/sbin/anacron exists, then the crontab line > > > > above will not run cron.daily. You say that /usr/sbin/anacron exists, so > > > > cron.daily is not being launched as a result of the above crontab line. > > > > That means something else is running it. Something like anacron, for > > > > example. > > > > > > This list is great. This explains a longstanding puzzle (to me) of how > > > (and to some extent why) both cron and anacron are installed on my debian > > > box. > > > > > > Now that I see how it works, I am not too impressed with this kludge, > > > though... this is a deceptively obtuse configuration duplication between > > > these two packages. > > > > ok, maybe i'm slow, but i don't understand why that line will only > > launch if /usr/sbin/anacron doesn't exist. > > The shell uses short-circuit evaluation on conditionals. When it sees > A || B > it first evaluates A. Then if A is true, the value of the whole > conditional has to be true, so B never even gets evaluated. > > So, if "test -e /usr/sbin/anacron" is true because anacron is installed, > then the shell doesn't bother with "run-parts --report /etc/cron.daily" > because it has already figured out the value of the conditional. > > On the other hand, if "test -e /usr/sbin/anacron" is false, then the > shell is looking at (false || "run-parts --report /etc/cron.daily"), > which evaluates to whatever the right-hand side evaluates to. aiiieeeeeee........
if i told you what going through my head, you wouldn't believe me. ok. ken, jeff, sam. sorry. i'll shut up now. pete -- Make everything as simple as possible, but no simpler. -- Albert Einstein GPG Instructions: http://www.dirac.org/linux/gpg GPG Fingerprint: B9F1 6CF3 47C4 7CD8 D33E 70A9 A3B9 1945 67EA 951D _______________________________________________ vox-tech mailing list [EMAIL PROTECTED] http://lists.lugod.org/mailman/listinfo/vox-tech