[ubuntu] 32 bit or 64 bit precise installation - which do I have?

view story

http://ubuntuforums.org – Hello everyone, I know this question sounds foolish....but I am compelled to ask anyway in spite of opprobrium I will (deservedly) receive. Two questions: 1. How do I query using the shell to determine which version (32 or 64 bit) of Ubuntu Precise I have installed. There must be a way. 2. If in fact I installed about a year ago the 32 bit version, how do I upgrade to 64 bit without disturbing --or minimally disturbing--existing files? Thanks, Mark Allyn (Hardware)