How to schedule R script in crontab on Mac Snow Leopard?

Question

So I have an R file that I would like to schedule to run every 10 minutes. I have created an entry for the file in crontab through the Terminal (using crontab -e). As so:

*/10    *       *       *       *       root    /Users/A/Documents/code/r/r_file.r

When I run the commands in the console it executes as designed and I can verify records in the database. However, with this cron setup I am not getting the end result.

I did get the following error message:

/bin/sh: root: command not found

I am sure this is a total rookie question as I do not have much experience with crontab. Any advice is greatly appreciated.

Thanks,

Jason

Answer 1

Is Rscript is in your path? More importantly, is it in path of the user running the commamd, here root? (Also consider running the command as you).

If so, try

*/10 * * * *      yourlogin    Rscript /Users/..../file.R

Test your understanding of crontab with a simpler job that just stores timestamps, maybe

*/10 * * * *      yourlogin    date > /tmp/testcrontab.txt

Once you have that mastered, run a simple R script and then move on to your real script.

Answer 2

The "root" part of you crontab line is what's screwing you up. When you use crontab -e, you should not specify the user because all the commands run as your current user (i.e. the user you are logged in as when you run crontab -e).

Also, you should always use full paths in your crontab.

The cron line should look like this:

*/10 * * * * /path/to/Rscript /Users/A/Documents/code/r/r_file.r