How can I compare file structures before and after a software install?
In Terminal I can think of two choice:


ls -R.
tree directory-name/ (after you install it; i.e. brew install tree). The slash at the end preserves the display of special characters in the file the output is saved to.


In both case you redirect the output to a file before and after installation and compare the two files possibly using Apple FileMerge.app shipped with Xcode.