List all unique extensions for files contained in a directory

Solution 1:

Try this:

find . -type f | sed -rn 's|.*/[^/]+\.([^/.]+)$|\1|p' | sort -u

It outputs nothing for:

• Files with no extension
• Files with names that end in a dot
• Hidden files

It also might be useful to pipe it to sort | uniq -c.

Solution 2:

find . -type f | sed -E 's/.+[\./]([^/\.]+)/\1/' | sort -u

Works on OS X, except for files without extension. My downloads folder:

DS_Store
dmg
exe
localized
msi
nib
plist
pmproj
rar
tgz
txt
webloc
zip

You might need sed -r instead?

Minor issue: Files without extensions print their name. Hidden files (such as .DS_Store) print their name without leading ..