Why basename with a suffix doesn't work in a subshell when used with find?

Question

The following command doesn't do the subtitution, why?

find ./ -name "*.dng" -exec echo `basename \{\} .dng`  \;

but this command work:

find ./ -name "*.dng" -exec basename \{\} .dng  \;

What I'm actually trying to do is to find all the dng in my hard drive and do:

touch -c -r {basename}.RW2  {basename}.dng

Answer 1

The following command doesn't do the subtitution, why?

find ./ -name "*.dng" -exec echo `basename \{\} .dng`  \;

As Cyrus already said in his comment, bash expands `basename \{\} .dng` to {} before invoking find; so what find receives is just echo {}, it doesn't see `basename \{\} .dng` part.

What I'm actually trying to do is to find all the dng in my hard drive and do:

touch -c -r {basename}.RW2 {basename}.dng

Assuming each reference file (*.RW2) is in the same directory as corresponding .dng file, I would do it like this:

find . -name '*.dng' -exec sh -c '
for dng do
  touch -c -r "${dng%.*}.RW2" "$dng"
done' _ {} +