Decoding a crontab command

This is my first question on stackoverflow :)

I need t开发者_如何学Co add the following cPanel's crontab for a site I just migrated to hostgator, however I am having trouble understanding it.

Here is cron command that was passed:

*/30    *    *    *    *    /usr/local/bin/php /data/web/vhosts/advisorcheck.com/cron/geocode_paid_members.php
0        9,15       *       *       *       /usr/bin/wget http://www.advisorbackgroundcheck.com/--spider

I need help in decoding the above and adding it to the crontab!

There is a useful site at http://cronwtf.github.com/ where you can paste cron lines and it will give you an English explanation of what it will do. Pasting your lines yields the following results:

Runs /usr/local/bin/php /data/web/vhosts/advisorcheck.com/cron/geocode_paid_members.php at minutes :00, :30, every hour.

Runs /usr/bin/wget http://www.advisorbackgroundcheck.com/--spider at minute :00, on hours 9, 15, every day.

There is also a perl module Schedule::Cron::Events that does something similar, this module is available in Ubuntu 16.04. Hopefully it is available via other distros package managers.

To install the module on ubuntu:

$ sudo apt install libschedule-cron-events-perl

Using this module in a script:

#!/usr/bin/perl

use strict;
use warnings;

use Schedule::Cron::Events;

my $cron_line = shift;

my $count = 10;

my $cron = new Schedule::Cron::Events($cron_line, Seconds => time() );
my ($sec, $min, $hour, $day, $month, $year);

print "The next $count events for the cron line:\n\n" . $cron_line . "\n\nwill be:\n\n";

for (1..$count) {
    # find the next execution time
    ($sec, $min, $hour, $day, $month, $year) = $cron->nextEvent;
    printf(
        "Event %02d will start at %02d:%02d:%02d on %d-%02d-%02d\n",
        $_,
        $hour,
        $min,
        $sec,
        ($year+1900),
        ($month+1),
        $day,
    );
}

$cron->resetCounter;
($sec, $min, $hour, $day, $month, $year) = $cron->previousEvent;
printf(
    "\nThe most recent event started at %02d:%02d:%02d on %d-%02d-%02d\n",
    $hour,
    $min,
    $sec,
    ($year+1900),
    ($month+1),
    $day
);

will produce the following output:

$ ./cron-events.pl '0 9,15 * * *'
The next 10 events for the cron line:

0 9,15 * * *

will be:

Event 01 will start at 15:00:00 on 2017-02-21
Event 02 will start at 09:00:00 on 2017-02-22
Event 03 will start at 15:00:00 on 2017-02-22
Event 04 will start at 09:00:00 on 2017-02-23
Event 05 will start at 15:00:00 on 2017-02-23
Event 06 will start at 09:00:00 on 2017-02-24
Event 07 will start at 15:00:00 on 2017-02-24
Event 08 will start at 09:00:00 on 2017-02-25
Event 09 will start at 15:00:00 on 2017-02-25
Event 10 will start at 09:00:00 on 2017-02-26

The most recent event started at 09:00:00 on 2017-02-21

The first command will be executed every 30 minutes, while the second one will be executed twice a day (at 9⁰⁰ and 15⁰⁰).

Here's an explanation of crontab syntax: http://en.wikipedia.org/wiki/Cron#Examples