Using links in crontab

• You should have spaces between the *
• Also as mentioned by @steeldriver - you have too many fields

Adding spaces and removing the extra * should work:

10 * * * * /path-to-link/

More info - how-do I add jobs to cron under linux

Example: Run backup cron job script

If you wished to have a script named /root/backup.sh run every day at 3am, your crontab entry would look like as follows. First, install your cronjob by running the following command:

crontab -e

Append the following entry:

0 3 * * * /root/backup.sh

Save and close the file.

How do I use operators?

An operator allows you to specifying multiple values in a field. There are three operators:

• The asterisk (*) : This operator specifies all possible values for a field. For example, an asterisk in the hour time field would be equivalent to every hour or an asterisk in the month field would be equivalent to every month.
• The comma (,) : This operator specifies a list of values, for example: “1,5,10,15,20, 25”.
• The dash (-) : This operator specifies a range of values, for example: “5-15” days , which is equivalent to typing “5,6,7,8,9,….,13,14,15” using the comma operator.
• The separator (/) : This operator specifies a step value, for example: “0-23/” can be used in the hours field to specify command execution every other hour. Steps are also permitted after an asterisk, so if you want to say every two hours, just use */2.

Yes you can use a link to a file in crontabs - with the same conditions as always e.g.

• the file that the link resolves to must be executable
• it must be able to run within the limted environment provided by cron

In fact, many common executable commands are symbolic links - even /bin/sh itself:

$ ls -l /bin/sh
lrwxrwxrwx 1 root root 4 Jan 11 13:58 /bin/sh -> dash

So for example

# m h  dom mon dow   command
40 * * * * /bin/sh -c 'echo "Hello from $0 (which is actually $(readlink -f $0))"' > /home/steeldriver/cron.out

results in

$ cat ~/cron.out
Hello from /bin/sh (which is actually /bin/dash)