Sometimes when you are digging around in the under pinnings of Mac OS X, you need to access folders and files that are normally hidden by the OS. Thankfully there is preference in the Finder for this, which you can turn on and off in the Terminal.

The command is:

defaults write com.apple.Finder AppleShowAllFiles YES

The Finder needs to be restarted for this change to take effect. Luckily there is a Terminal command for this too:

killall Finder

Once you are done playing around with hidden files, you can stop showing them by replacing YES with NO in the original terminal command.

defaults write com.apple.Finder AppleShowAllFiles NO

It is as simple as that, but make sure your don’t break anything.