Showing hidden files by default:
Run this to show hidden files in Finder again:
defaults write com.apple.finder AppleShowAllFiles -bool true osascript -e ‘tell application “Finder” to quit’ open -a Finder
Run this to hide them again:
defaults write com.apple.finder AppleShowAllFiles -bool false osascript -e ‘tell application “Finder” to quit’ open -a Finder