recursively add file extension to all files

Question

I have a few directories and sub-directories containing files with no file extension. I want to add .jpg to all the files contained within these directories. I\

Answer 1

like this,

for f in $(find . -type f); do mv $f ${f}.jpg; done

I am not expecting you have space separated file names,
If you do, the names will need to be processed a bit.

If you want to execute the command from some other directory,
you can replace the find . with find /target/directory.