I am reading the book Programming Ruby and am looking to upgrade the version of Ruby on my computer. I run Mac OS X Snow Leopard and doing ruby -v in the command line shows I am running Ruby 1.8.7.
I installed MacPorts and ran the sudo port install ruby19 command but whenever I type ruby -v, it still shows Ruby 1.8.7.
Could anyone help with this? Thank you.
You have to use ruby19 to run ruby if you installed it that way. You can also use irb19, and ri19.
The tool "rvm" is pretty good. It stands for Ruby Verson Manager I think, and the developer is good at support in the irc channels. You can install multiple versions of ruby along side each other pick the ones you want to use.
As @Andrew Grimm eluded, the problem you are having is likely due to a problem in your $PATH variable. Since macports typically installs stuff in /opt, modifying your $PATH variable to:
$ export PATH=/opt/local/bin:$PATH
Will most likely help. However, I would urge you to look into RVM as @hvgotcodes recommends.
As mentioned in hvgotcodes answer, RVM seems to be a great way of handling this.
I recently started learning Ruby (and Rails) myself, and this[1] tutorial has a great section on using RVM. I'd highly recommend you give it a go, it's especially handy so that you can follow different tutorials on different versions of Ruby if you wish.