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FreeBSD hs32.drive.ne.jp 9.1-RELEASE FreeBSD 9.1-RELEASE #1: Wed Jan 14 12:18:08 JST 2015 root@hs32.drive.ne.jp:/sys/amd64/compile/hs32 amd64 |
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$FreeBSD: release/9.1.0/usr.sbin/cron/doc/CONVERSION 72091 2001-02-06 11:21:58Z asmodai $ Conversion of BSD 4.[23] crontab files: Edit your current crontab (/usr/lib/crontab) into little pieces, with each users' commands in a different file. This is different on 4.2 and 4.3, but I'll get to that below. The biggest feature of this cron is that you can move 'news' and 'uucp' cron commands into files owned and maintainable by those two users. You also get to rip all the fancy 'su' footwork out of the cron commands. On 4.3, there's no need for the 'su' stuff since the user name appears on each command -- but I'd still rather have separate crontabs with separate environments and so on. Leave the original /usr/lib/crontab! This cron doesn't use it, so you may as well keep it around for a while in case something goes wakko with this fancy version. Most commands in most crontabs are run by root, have to run by root, and should continue to be run by root. They still have to be in their own file; I recommend /etc/crontab.src or /usr/adm/crontab.src. 'uucp's commands need their own file; how about /usr/lib/uucp/crontab.src? 'news' also, perhaps in /usr/lib/news/crontab.src... I say `how about' and `perhaps' because it really doesn't matter to anyone (except you) where you put the crontab source files. The `crontab' command COPIES them into a protected directory (CRONDIR/SPOOL_DIR in cron.h), named after the user whose crontab it is. If you want to examine, replace, or delete a crontab, the `crontab' command does all of those things. The various `crontab.src' (my suggested name for them) files are just source files---they have to be copied to SPOOLDIR using `crontab' before they'll be executed. On 4.2, your crontab might have a few lines like this: 5 * * * * su uucp < /usr/lib/uucp/uudemon.hr 10 4 * * * su uucp < /usr/lib/uucp/uudemon.day 15 5 * * 0 su uucp < /usr/lib/uucp/uudemon.wk ...or like this: 5 * * * * echo /usr/lib/uucp/uudemon.hr | su uucp 10 4 * * * echo /usr/lib/uucp/uudemon.day | su uucp 15 5 * * 0 echo /usr/lib/uucp/uudemon.wk | su uucp On 4.3, they'd look a little bit better, but not much: 5 * * * * uucp /usr/lib/uucp/uudemon.hr 10 4 * * * uucp /usr/lib/uucp/uudemon.day 15 5 * * 0 uucp /usr/lib/uucp/uudemon.wk For this cron, you'd create /usr/lib/uucp/crontab.src (or wherever you want to keep uucp's commands) which would look like this: # /usr/lib/uucp/crontab.src - uucp's crontab # PATH=/usr/lib/uucp:/bin:/usr/bin SHELL=/bin/sh HOME=/usr/lib/uucp # 5 * * * * uudemon.hr 10 4 * * * uudemon.day 15 5 * * 0 uudemon.wk The application to the `news' cron commands (if any) is left for you to figure out. Likewise if there are any other cruddy-looking 'su' commands in your crontab commands, you don't need them anymore: just find a good place to put the `crontab.src' (or whatever you want to call it) file for that user, put the cron commands into it, and install it using the `crontab' command (probably with "-u USERNAME", but see the man page). If you run a 4.2-derived cron, you could of course just install your current crontab in toto as root's crontab. It would work exactly the way your current one does, barring the extra steps in installing or changing it. There would still be advantages to this cron, mostly that you get mail if there is any output from your cron commands. One note about getting mail from cron: you will probably find, after you install this version of cron, that your cron commands are generating a lot of irritating output. The work-around for this is to redirect all EXPECTED output to a per-execution log file, which you can examine if you want to see the output from the "last time" a command was executed; if you get any UNEXPECTED output, it will be mailed to you. This takes a while to get right, but it's amazingly convenient. Trust me.