03_Creating_CRONS.md

Managing Crons - Linux (Debian)

Install cron

First thing make sure that cron is installed:

which cron

If it's not the case simply install it by executing the following command:

sudo apt-get install cron

Cron structure

* * * * * command_to_be_executed
| | | | |
| | | | +----- Day of the Week   (0 - 6) (Sunday = 0)
| | | +------- Month             (1 - 12)
| | +--------- Day of the Month  (1 - 31)
| +----------- Hour              (0 - 23)
+------------- Minute            (0 - 59)

Create a new cron

Let's assume we want to run a python script each minute, we have to run the following command to edit the crontab:

crontab -e

then add a new line representing the shell command to run, in our case it would be:

*/1 * * * * python /path_to_script/script.py

You can use https://crontab.guru to get the right cron to be used.

You can then show the list of crons using

crontab -l

⚠️ to manage crons using python, you can use python-crontab