How to know that your machine hardware supports 64 bit OS

Once I was trying to install Docker for my project. I was looking at the documentation of docker and get to know that Docker is only works on 64 bit machine. I was running with Ubuntu 14.04 32.....

RVM shows message and takes time in Regenerating Ruby version Wrappers...

To use specific version of ruby, I used to create file .ruby-version in my rails application. Which will execute when I go to root directory of my project using cd command.

Once I was having.....