Mac: Remove (non-empty) folders

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Console Command:

sudo rm -r folderName

Read further: http://www.macworld.com/article/2082021/master-the-command-line-deleting-files-and-folders.html

Mac: start TextEditor from the command line

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Console Command:
$ open -a TextEdit readme.txt

Mac: Display a tree-like structural view of any directory

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Console Command:
ls -R | grep ":" | sed -e 's/://' -e 's/[^-][^\/]*\//--/g' -e 's/^/   /' -e 's/-/|/'