Stupid question but what is the best way to insert a line to crontab from /boot/config/go script? I need to put a script to run each minute or two (for controlling fan speed) and /etc/cron.hourly is just too long.

 

Thanks!

 

# need the following to go to crontab from /boot/config/go

*/2 * * * * /boot/scripts/unraid-fan-speed.sh 1>/dev/null 2>&1

Stupid question but what is the best way to insert a line to crontab from /boot/config/go script? I need to put a script to run each minute or two (for controlling fan speed) and /etc/cron.hourly is just too long.

 

Thanks!

 

# need the following to go to crontab from /boot/config/go

*/2 * * * * /boot/scripts/unraid-fan-speed.sh 1>/dev/null 2>&1

 

I'd do it like this:

chmod +x /usr/local/bin/unraid-fan-speed.sh

crontab -l >/tmp/crontab

grep -q "unraid-fan-speed.sh" /tmp/crontab 1>/dev/null 2>&1

if [ "$?" = "1" ]

then

    crontab -l | egrep -v "control unRAID fan speed based on temperature:|unraid-fan-speed.sh" >/tmp/crontab

    echo "# control unRAID fan speed based on temperature:" >>/tmp/crontab

    echo "*/2 * * * * /usr/local/sbin/unraid-fan-speed.sh 1>/dev/null 2>&1" >>/tmp/crontab

    cp /tmp/crontab /var/spool/cron/crontabs/root-

    crontab /tmp/crontab

fi

In addition to adding the line to the new crontab, You must copy the new crontab file to /var/spool/cron/crontabs/root-  (with a trailing "dash" on the end)

since unRAID'd emhttp does not re-read the crontab if you make changes.  It uses the file for its next starting point.

Joe, thanks. Is it any good to copy directly a saved version of crontab to /var/spool/cron/crontabs/root and root-

I don't think it's good form to just use a saved static copy of a file that by it's nature should be dynamic.

 

With that said, on a rarely used environment you could likely get by without issue. Likewise in the future, if anything would change on the base unRAID distro or a new addon uses it, you might be spending time troubleshooting why something doesn't work unless you remember to double-check this overwrite.

With that said, on a rarely used environment you could likely get by without issue. Likewise in the future, if anything would change on the base unRAID distro or a new addon uses it, you might be spending time troubleshooting why something doesn't work unless you remember to double-check this overwrite.

 

Very true, thanks again!

I don't think it's good form to just use a saved static copy of a file that by it's nature should be dynamic.

 

With that said, on a rarely used environment you could likely get by without issue. Likewise in the future, if anything would change on the base unRAID distro or a new addon uses it, you might be spending time troubleshooting why something doesn't work unless you remember to double-check this overwrite.

I agree.  submit it as a "bug" to lime-tech.  It is their brain-damaged handling of crontab when dealing with the "mover" script that causes the issue.  They did not expect anybody else to be changing crontab.

 

I do not use the saved copy of crontab, emhttp does.  I always grab it dynamically using "crontab -l"

 

Joe L.