问题
I found out that I have two versions of ruby installed on OSX 10.6.2 how can I uninstall the older version and make sure that everything is fine, the path point to the other one?
bash-3.2$ /usr/local/bin/ruby -v
ruby 1.8.7 (2009-06-12 patchlevel 174) [i686-darwin9.7.0]
bash-3.2$ /usr/bin/ruby -v
ruby 1.8.7 (2008-08-11 patchlevel 72) [universal-darwin10.0]
bash-3.2$ $PATH
bash: /usr/local/bin:/bin:/sbin:/usr/bin:/usr/sbin:/usr/libexec: No such file or directory
bash-3.2$ whereis ruby
/usr/bin/ruby
回答1:
The version of Ruby in /usr/bin is the system-installed version, and should be left in place.
The version you have in /usr/local/bin can probably be safely removed. Was it installed using a package manager (ie, MacPorts, Homebrew?). If so, remove it using your package manager.
If you compiled and installed it manually, you can try removing the binaries from /usr/local/bin, but you may still have gems and other files lying around (most likely in /usr/local/lib/ruby.)
Alternatively, you can leave them in place and manage your Ruby environment through RVM: http://rvm.beginrescueend.com/
回答2:
You don't have to uninstall the the older version. ALternatively you can use alias like and save it in the ~/.profile file of your the OSX directory.
alias ruby="<path_to_ruby_version_that_you_want_to_use>"
That should call ruby from the proper directory that you want.
Alternatively you can use symlink like this post suggests here How to uninstall Ruby from /usr/local?. Hope it helps!
回答3:
You should locate the Ruby you're actively using with which ruby, not whereis ruby. My whereis ruby outputs /usr/bin/ruby, but which ruby gives /Users/BinaryMuse/.rvm/rubies/ruby-1.9.2-p136/bin/ruby, because I manage my Ruby versions with RVM. Since /usr/local/bin is first in your PATH, which ruby will probably return /usr/local/bin/ruby, which appears to be what you want. A quick ruby -v can confirm this too.
All that being said, I second the recommendation of using RVM to manage version of Ruby and also what RVM calls gemsets, allowing you to have "buckets" of gems that you can use one at a time. It's quite a powerful and extremely useful tool.
来源：https://stackoverflow.com/questions/5213878/two-versions-of-ruby-installed-how-to-fix-that