How to create password protected folder in linux

htpasswd -c /var/www/folder_name/.htpasswd <username>

Should be prompted with new password

How to change default IDE of Ubuntu

Change default nano editor to vim

sudo update-alternatives –config editor

then…select vim

How to install :

# apt-get install <app_name>

How to remove :

#apt-get remove –purge <app_name>
#apt-get clean

Note:

<app_name> must be exactly the same from install to remove the application