Change default crontab editor on Ubuntu
When you edit crontab for the first time on a Linux Ubuntu you will be asked which editor you want to use.
If you want to chage your first choice, maybe after adding another editor to your Ubuntu installation you may issue the following command
select-editor
Backup your bash history to a file
Flush the history to the file
history -w historybackup.txt
where historybackup.txt is the file name where to save your history.
Clear bash history completely
Flush the history to the file
history -w
Clear the history
history -c
Change keyboard layout from terminal type:
dpkg-reconfigure keyboard-configuration