The best way if you’re running as root, is to drop a file into /etc/cron.d if you use a package manager to package your software, you can simply lay down files in that directory and they are interpreted as if they were crontabs, but with an extra field for the username, e.g.: Filename: /etc/cron.d/per_minute Content: … Read more
This can happen if curl is asked to do plain HTTP on a server that does HTTPS. Example: $ curl http://google.com:443 curl: (52) Empty reply from server
I used /etc/crontab. I used vi and entered in the PATHs I needed into this file and ran it as root. The normal crontab overwrites PATHs that you have set up. A good tutorial on how to do this. The systemwide cron file looks like this: This has the username field, as used by /etc/crontab. … Read more
Here’s a good tutorial on what crontab is and how to use it on Ubuntu. Your crontab line will look something like this: 00 00 * * * ruby path/to/your/script.rb (00 00 indicates midnight–0 minutes and 0 hours–and the *s mean every day of every month.) Syntax: mm hh dd mt wd command mm minute … Read more
Use flock. It’s new. It’s better. Now you don’t have to write the code yourself. Check out more reasons here: https://serverfault.com/a/82863 /usr/bin/flock -n /tmp/my.lockfile /usr/local/bin/my_script
Instead of creating a crontab to run as the root user, create a crontab for the user that you want to run the script. In your case, crontab -u www-data -e will edit the crontab for the www-data user. Just put your full command in there and remove it from the root user’s crontab.
Here’s a one-liner that doesn’t use/require the new job to be in a file: (crontab -l 2>/dev/null; echo “*/5 * * * * /path/to/job -with args”) | crontab – The 2>/dev/null is important so that you don’t get the no crontab for username message that some *nixes produce if there are currently no crontab entries.
It’s running every minute of the hour 22 I guess. Try the following to run it every first minute of the hour 22: 0 22 * * * ….
0 and 7 both stand for Sunday, you can use the one you want, so writing 0-6 or 1-7 has the same result. Also, as suggested by @Henrik, it is possible to replace numbers by shortened name of days, such as MON, THU, etc: 0 – Sun Sunday 1 – Mon Monday 2 – Tue … Read more
Just do what cron does, run the following as root: run-parts -v /etc/cron.weekly … or the next one if you receive the “Not a directory: -v” error: run-parts /etc/cron.weekly -v Option -v prints the script names before they are run.