How to find all file extensions recursively from a directory?
How about this:
find . -type f -name '*.*' | sed 's|.*\.||' | sort -u
list all extensions and their counts of current and all sub-directories
ls -1R | sed 's/[^\.]*//' | sed 's/.*\.//' | sort | uniq -c
find . -type f | sed 's|.*\.||' | sort -u
Also works on mac.