cronjobs do not run

Question

I have recently switched from Ubuntu to MacOS. I tried to run the exact same cronjobs I ran on Ubuntu before, however they don't, and after trying to figure out if the crontab entries might have any errors, I more and more had the suspicion that cronjobs don't run on my MBP at all, so I added this line to crontab -e:

*/15 * * * * touch /Users/<my-user>/cronjob-success-"$(date +%Y%m%d)".txt

I'd expect it to run every 15 min (xxh15, xxh30, ...), however no new files appear. I also don't see any logs indicating cronjob runs.

The file exists in /usr/lib/cron/tabs/<my-user>. What am I doing wrong that this doesn't work?

I am on Catalina 10.15.6

You will need to grant permissions for command line tools to run on Catalina. — bmike, Sep 26 '20 at 22:10
I apologize. My comment was entered as an answer and come code has decided it’s a comment and not an answer. See https://apple.meta.stackexchange.com/questions/3969 for details. — bmike, Sep 26 '20 at 22:13
Also, did you add terminal app to the full disk entitlements and log out / restart? — bmike, Sep 26 '20 at 22:27
I added iTerm which I actually use, but also the Terminal app, as well as cron and crontab to Full Disk Access. I hadn't restarted, but did now. No success. — Yanick Nedderhoff, Sep 26 '20 at 23:03
cron treats % characters in the command as line delimiters; you need to escape them like ...date +\%Y\%m\%d... for the command to work. — Gordon Davisson, Sep 27 '20 at 00:01
@SteveChambers I have it on good authority it’s still in the Big Sur betas! — bmike, Sep 27 '20 at 18:45

Seamus · Accepted Answer · 2023-06-13T01:22:17.213

8

I'd recommend a couple of things:

Make sure cron has Full Disk Access in the Privacy tab of System Preferences (see s/s below)

When creating commands in crontab, help yourself out by writing errors generated by stderr to an output file using 2>&1, and using full pathnames (your cron job does not run w/ same environment as your user does);

EXAMPLE:

seamus@Dung-Pro ~ % crontab -l
/5  * * * /usr/bin/touch /Users/seamus/scripts/cronjob-success-"$(date)".txt

SOME OTHER IDEAS:

crontab guru: https://crontab.guru/
not always necessary, but using full path to command is a good habit!
it often helps to re-direct stderr (aka 2) to a file for review when things go wrong
re-direct may be done as follows:
>> /home/pi/cronjoblog 2>&1

This redirects stdout to /home/pi/cronjoblog and redirects stderr to stdout; i.e. both streams will be written to the file.
Finally, wrt the specific command in your question: that does not run for me either - it has something to do with the formatting specified for the date command - date with no formatting works fine. If you need to use that specific format, you should try @GordonDavisson comment to your question.

edited Jun 13 '23 at 01:22

answered Sep 27 '20 at 15:57

Seamus

4,547

2

Hey! Thanks for this. Others were partly right, but your answer is the most complete. In fact I had (and partly still have) a series of issues. Firstly, indeed I had to give Full Disk Access to cron. Secondly, it my test cronjob was indeed faulty and did not work. Your example did! I also logged stderr now and got /bin/sh: flock: command not found. I use flock to not run the same rsync twice. I am aware that it's original a linux thing, but I have installed https://github.com/discoteq/flock and the rsync works with flock from my user. I suspect cron uses another user and that breaks it? – Yanick Nedderhoff Sep 27 '20 at 16:48
If I type which flock I get /usr/local/bin/flock. I am not sure what to do with this though. – Yanick Nedderhoff Sep 27 '20 at 16:49
So, turns out I ignored one part of your answer. I had to specify the full path as you said (/usr/local/bin/flock) and it worked :) Thank you! – Yanick Nedderhoff Sep 27 '20 at 17:31
1

@YanickNedderhoff: Glad that helped. cron is an invaluable tool, IMHO. The key to getting results is (as in most things), is understanding its limitations. And thanks for the feedback - I should have made that business with the full path specification more prominent. – Seamus Sep 27 '20 at 17:57
2

I wish I could give you both more than one upvote. Super helpful explanations how to get to the right set of fixes. – bmike Sep 27 '20 at 18:33

score 2 · Answer 2 · edited Oct 02 '20 at 22:43

2

grant permissions for cron and possible the terminal apps / command line tools to run on Catalina.
check for full paths everywhere...
consider putting your commands in a script so you can debug them and avoid needing to escape characters like % or run cron in debug/test mode

edited Oct 02 '20 at 22:43

Wowfunhappy

7,383

answered Sep 26 '20 at 22:15

bmike

235,889

I did read about this before, but it does not seem to fix the issue in my case. I did at /usr/sbin/cron to Full Disk Access, but still the jobs don't run. – Yanick Nedderhoff Sep 26 '20 at 22:20
Also, where do cronjob logs show up so I can try to have a look? – Yanick Nedderhoff Sep 26 '20 at 22:21
@YanickNedderhoff I’ll have to dig for that. I converted 100% of my jobs to launchctl so I don’t need to futz with all the setup. – bmike Sep 26 '20 at 22:25
launchctl is new to me. I might move to that but first would like to get my existing setup migrated to MacOS. – Yanick Nedderhoff Sep 26 '20 at 23:04
1

I’ve edited my short answer in case it helps others in hindsight. Great work with Seamus - they are ace on the command line along with a few others here :) – bmike Sep 27 '20 at 18:33
2

@YanickNedderhoff: IMHO, launchctl is horribly arcane without the help of LaunchControl. – Seamus Sep 27 '20 at 18:33

cronjobs do not run

2 Answers2

SOME OTHER IDEAS:

Linked