Basic functions of cron job in Asuswrt Merlin Wifi Router

Add a new cron job

cru a {id} min hour day moth week command

Where:

• id – Unique ID for each cron job
• min – Minute (0-59)
• hour – Hours (0-23)
• day – Day (0-31)
• month – Month (0-12 [12 is December])
• week – Day of the week(0-7 [7 or 0 is Sunday])
• command – Script or command name to schedule.

List cron jobs

cru l

Delete cron job

cru d {id}

Example of Cron Job

Let us add cron job on Asuswrt Merlin Wifi router to ping gateway every 1 hour, run:

cru a pinggw "0 * * * * /bin/ping -c 10 -q 192.168.2.254"

Above cron job will run /bin/ping command that sends only 10 pings and only display output at start.
To list current jobs run:

cru l

To delete current jobs run:

cru d pinggw

Verify it:

cru l

Create/Edit a script called services-start

Type the following command

vi /jffs/scripts/services-start

And add your command like below. Below is the case to update DNS every 10mins

cru a ddns "*/10 * * * * /usr/sbin/wget -O /dev/null 'http://ddns.dnszi.com/set.html?user=<your_id>&auth=<your_auth>&domain=<your_domain>&record=<your_record>'"

To enable boot time support for /jffs/scripts/, you should check following options