
Here is my attempt to rename the files: $ ls


NOTE: The files are stored on a NAS (Synology DS1813+). My question is why does the proposed solution not work and how do I accomplish renaming the files such that I am only modifying the filename by making the extension lowercase? I found this question and answer but the proposed solution doesn't work.

When I copy files from my camera to my computer the filename extension is upper case.
