Answer by GrayedFox for Why crontab scripts are not working?

The default .bashrc files on UBuntu 16.04 (and many other versions) have a built in mechanism to not do anything if they are not an interactive shell.

This can prevent the file from being sourced correctly inside a script that is run by cron! To prevent this, comment out the following lines from the top of your .bashrc file:

Ubuntu 16.04

# If not running interactively, don't do anythingcase $- in    *i*) ;;      *) return;;esac

Ubuntu 12.04 and some other versions

# If not running interactively, don't do anything[ -z "$PS1" ] && return

So long as these are left in if cron runs a script which sources your .bashrc file you won't actually get any of the environment variables you are used to inside your terminal!