How to create a cron job using Bash automatically without the interactive editor?

Source: How to create a cron job using Bash automatically without the interactive editor?

Does crontab have an argument for creating cron jobs without using the editor (crontab -e). If so, What would be the code create a cronjob from a Bash script?

Answer 1:

You can add to the crontab as follows:

#write out current crontab
crontab -l > mycron
#echo new cron into cron file
echo "00 09 * * 1-5 echo hello" >> mycron
#install new cron file
crontab mycron
rm mycron

Cron line explaination

* * * * * "command to be executed"
- - - - -
| | | | |
| | | | ----- Day of week (0 - 7) (Sunday=0 or 7)
| | | ------- Month (1 - 12)
| | --------- Day of month (1 - 31)
| ----------- Hour (0 - 23)
------------- Minute (0 - 59)
Source nixCraft.

Answer 2:

(crontab -l ; echo "00 09 * * 1-5 echo hello") | crontab -