How to remove files with filenames all in uppercase in linux?

Question

Say I have a directory containing the following files:

ls

ABC BCD CDE DEF abc bcd cde def Abc

How to remove all the files with filenames all in uppercase? (remove ABC BCD CDE DEF in this case)

Answer 1

Using GNU find:

find . -maxdepth 1 ! -name '*[![:upper:]]*' -delete

Note that this does not descend into subdirectories and does not delete non-empty directories whose filenames are all in uppercase.