Re: CRON tidbit

[Frank Miedreich <miedreich@acm.org>]

******    message to minivend-users from Frank Miedreich <miedreich@acm.org>     ******

>******    message to minivend-users from "Thompson-Jordan"
><Thompson-Jordan@mindspring.com>     ******
>
>I am sure that you all know everything there is to know about cron and
>crontab, but I just learned what the format of those cron files is and
>thought I would share it. In the Minivend manual it says:
>
>     - Put this in crontab to expire session database
>     44 4 * * * /home/user/minivend/bin/expireall -r
>
>What that line does is run the Minivend expireall program at 4:44 am each
>morning. Why that wasn't clear to me I'll never know :-) Hey Mike? Why
>4:44?
>
>The format for lines in your crontab is:
>
>     minute hour day month year program
>
>An asterisk mean "do every", so:
>
>     44 4 * * *    is every day at 4:44
>
>     30 12 1 * *   is every month on the 1st at 12:30
>
>There are a bunch of other complex and even more cryptic ways to specify
>dates and times (after all it is Unix). On my system you type the
>following to list your crontab (you may not need "-u username"):
>
>     crontab -u username -l
>
>To edit the crontab type the following, which brings up vi:
>
>     crontab -u username -e
>
>Good luck.
>

Please note that the fifth field is not the year, but the day of the week,
0 is Sunday and 6 is Saturday. Thus a line like:

32 23 * * 0 /home/user/minivend/bin/restart

would restart the server every sunday night at 11:32pm. For a less cryptic
way to specifiy times you can also say

32 23 * * sun /home/user/minivend/bin/restart

on many systems.

You can get the documentation by using
man crontab
to explain the command and
man 5 crontab
to get a complete explanation of the syntax for the crontab file.

The output of the command will be send to you via email, unless you append
a output redirection:
32 23 * * sun /home/user/minivend/bin/restart > /dev/null
would delete the output.

--
Frank Miedreich
Max-Planck-Institut fuer psychologische Forschung


-
To unsubscribe from the list, DO NOT REPLY to this message.  Instead, send
email with 'UNSUBSCRIBE minivend-users' in the body to Majordomo@minivend.com.
Archive of past messages: http://www.minivend.com/minivend/minivend-list