Question

I need unix cron command to run every 12 hours.

I have 500+ sub blogs in my server.

This is the file i want to run every 12 hours

http://*.mysite.com/somedir/index.php

Where * is my subdomain of my blogs.

I need cron command for all blogs.
Is it possible to run all of them with single command?
OR do i have to create command for each blog?

Answer 1

A crontab file has five fields for specifying day , date and time followed by the command to be run at that interval.

*     *     *   *    *        command to be executed
-     -     -   -    -
|     |     |   |    |
|     |     |   |    +----- day of week (0 - 6) (Sunday=0)
|     |     |   +------- month (1 - 12)
|     |     +--------- day of        month (1 - 31)
|     +----------- hour (0 - 23)
+------------- min (0 - 59)

* in the value field above means all legal values as in braces for that column.

You could use 0 1,13 * * * which means for every 1AM and 1PM.

0 1,13 * * * rm /var/www/*/somedir/index.php > /home/someuser/cronlogs/some.log 2>&1

where * can be replaced by different domain names.