Yes, it is good for the Proletariat to have those things in hiding. If I would also have to worry about the /etc directory, I would become totally insane. No, we just ask our questions, like John did, and let you do the dive into the deep dark unknown. Thanks, Lee, for all this help. I shall be definitely happier when I brush around with the macjanitor broom now. I just need to upgrade to 1.3 now. Marta
On Jan 13, 2006, at 9:37, Profile wrote: > Lee, > > Thanks so much, this is VERY informative, it also is a pleasure to > hear someone of intelligence speak (type). I'll see about upgrading > MacJanitor. > > John R. > > > On Jan 13, 2006, at 9:14 AM, Lee Larson wrote: > >> Yesterday I wrote that Apple has changed the way they do the periodic >> maintenance jobs on Mac OS X. I spent some time last night figuring >> out how it's being done now. Here's what's happening. >> >> The way most Unix systems have done the periodic maintenance from >> time immemorial is to schedule them as cron jobs. The cron daemon on >> a Unix system is a program that runs quietly in the >> background--that's why it's called a daemon--keeping track of a list >> of commands and times at which to run those commands. Each user can >> have a table of scheduled jobs, called a crontab. The mother of all >> crontabs is the system crontab, that's owned by the operating system >> itself. The system crontab listed the times to run the scripts called >> daily, weekly and monthly, to do periodic maintenance. >> >> The scripts are still there in the latest versions of Mac OS X. You >> just have to look in the /etc directory. The scripts are still there, >> but they are not used. >> >> To tell you what's being done now, I must go off on a tangent. >> >> Unix systems have had a very confusing way of starting things up when >> they are booted. Some things are launched by one set of scripts and >> another set of things are launched by another method entirely. (Linux >> users should think of rc.d and xinetd.) Apple wanted to clean this >> up, so they invented a new traffic cop that's the very first program >> launched by the kernel and called it launchd. (The "d" on the end is >> a clue that launchd is also a daemon.) All the startup stuff is >> handled in one place by launchd. Most of the functionality of crond >> was rolled into launchd, so Apple has turned off cron in Tiger. >> >> The new launchd periodically calls a program called periodic to >> handle the rest of the stuff crond used to do. The periodic program >> has its own cleanup scripts in the directory /etc/periodic/daily, >> /etc/periodic/monthly and /etc/periodic/weekly. (The /etc directory >> is invisible in the Finder because Apple is trying to hide the geeky >> Unix stuff from the proletariat.) >> >> As of version 1.3, MacJanitor calls the periodic program instead of >> the old crond scripts, so it should be safe to use it. (I have not >> tried it.) >> > > > > | The next meeting of the Louisville Computer Society will > | be January 24 at Pitt Academy, 6010 Preston Highway. > | The LCS Web page is <http://www.kymac.org>. > | List posting address: <mailto:macgroup at erdos.math.louisville.edu> > | List Web page: <http://erdos.math.louisville.edu/macgroup> | The next meeting of the Louisville Computer Society will | be January 24 at Pitt Academy, 6010 Preston Highway. | The LCS Web page is <http://www.kymac.org>. | List posting address: <mailto:macgroup at erdos.math.louisville.edu> | List Web page: <http://erdos.math.louisville.edu/macgroup>
