Category Archives: Unix

The basics on vi editor

Invest half an hour of your life watching these videos. It’s worthy. The vi editor is built-in on any single Unix / Linux operating system distribution I’ve seen in my life.

Through these four basic videos you will learn how to enter vi, switch from the command to the insert mode and viceversa, how to navigate through a file and how to insert and delete text on it.

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Thanks to devdaily for this.


How to enable Cron for non-root users

If you try to edit a user’s crontab and get this error:

”crontab: you are not authorized to use cron.  Sorry.”

You need to log in as root and edit a config file to add the user that you want to access Cron too:

# vi /usr/lib/cron/cron.allow

We add the user:


We save & close.

Now we log in with the user and we are able to access its crontab:

$ crontab -e

[Seen: Nekan]